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    Exploring and measuring the co-existence between LTE and DVB-T2-Lite services

    Polak, L. ; Kaller, O. ; Klozar, L. ; Prokopec, J.
    Telecommunications and Signal Processing (TSP), 2013 36th International Conference on

    DOI: 10.1109/TSP.2013.6613943
    Publication Year: 2013 , Page(s): 316 - 320

    IEEE Conference Publications

    The development and effective use of wireless communication systems to provide mobile services is rapidly increasing. Nowadays, the world's most perspective standards to provide wireless multimedia services in high quality are LTE (Long-Term Evolution) and DVB-T2 Lite (DVB-2nd Generation Terrestrial). On the other hand, these wireless multimedia systems can many times operate in a neighboring frequency spectrum. Therefore, as a result, numerous co-existence scenarios are possible. The focus of this paper is to explore and measure the co-existence between LTE and DVB-T2 Lite multimedia services. Theoretical backgrounds of the coexistence scenarios, general workplace and the principle of the measuring method of the influence of the LTE services on DVB-T2 services and vice versa are clearly presented and described. Furthermore, deeper investigation of the mutual influence of the DVB-T2 system on the LTE system is also explored and graphically illustrated. Finally, all obtained results are evaluated and future work is outlined. View full abstract»

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    Spectrum sharing between S-band radar and LTE cellular system: A spatial approach

    Khawar, A. ; Abdel-Hadi, A. ; Clancy, T.C.
    Dynamic Spectrum Access Networks (DYSPAN), 2014 IEEE International Symposium on

    DOI: 10.1109/DySPAN.2014.6817773
    Publication Year: 2014 , Page(s): 7 - 14
    Cited by:  Papers (4)

    IEEE Conference Publications

    Spectrum sharing is a new way forward to solve spectrum scarcity problem. In this paper, we propose a spatial approach for spectrum sharing between a MIMO radar and an LTE cellular system with NBS base stations (BS). The MIMO radar and LTE share NBS interference channels i.e. Hi, i = 1,2, ..., NBS. We propose projecting the radar signal onto the null space of interference channel between the MIMO radar and LTE using our proposed interference-channel-selection algorithm, in order to have zero-interference from the MIMO radar. We select interference channel with the maximum null space i.e. arg max1≤i≤NBS dim [N(Hi)] and project the radar signal onto the null space of this channel. Our proposed spatial spectrum-sharing algorithm is radar-centric such that it causes minimum loss in radar performance by carefully selecting the interference channel and at the same time protects the ith LTE BS from the radar interference. Through our analytical and simulation results we show that the loss in the radar performance is less when the proposed interference-channel-selection algorithm is used to select the channel onto which radar signals are projected. View full abstract»

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    Planning of Mobile TV service in standalone and cooperative DVB-NGH and LTE networks

    Razzac, A.A. ; Elayoubi, S.E. ; Chahed, T. ; El Hassan, B.
    Modeling & Optimization in Mobile, Ad Hoc & Wireless Networks (WiOpt), 2013 11th International Symposium on

    Publication Year: 2013 , Page(s): 609 - 614

    IEEE Conference Publications

    We study in this paper the planning of DVB-NGH and LTE, both separately and in cooperation, for the offering of mobile TV service. For the case of standalone DVB-NGH, we show the trade-off between coverage and capacity. In the case of standalone LTE, we evaluate the need for expensive infrastructure deployment. In the DVB-NGH/LTE cooperative case, we investigate two scenarios: coverage extension and service extension and show how both DVB-NGH and LTE benefit from the two cooperation schemes: DVB-NGH can extend its coverage and offered services and LTE is able to decrease its infrastructure and hence cost. View full abstract»

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    Antenna selection in LTE: from motivation to specification

    Mehta, N.B. ; Kashyap, S. ; Molisch, A.F.
    Communications Magazine, IEEE

    Volume: 50 , Issue: 10
    DOI: 10.1109/MCOM.2012.6316788
    Publication Year: 2012 , Page(s): 144 - 150
    Cited by:  Papers (6)

    IEEE Journals & Magazines

    Transmit antenna selection technology has been adopted for the uplink by the next generation Long Term Evolution wireless standard in order to harness the spatial diversity offered by multiple antennas at the mobile transmitter, while keeping the hardware complexity and cost of a mobile low. In TAS, the number of RF chains for processing/up-conversion is smaller than the number of available antenna elements, so at any time the signals can only be transmitted from a (dynamically optimized) subset of antenna elements. As a result, the training procedure for AS needs to be carefully engineered. In LTE, this is accomplished by reusing the wideband sounding reference signal for the purpose of AS training. Furthermore, new mechanisms are required to facilitate feedback from the receiver (the base station) to the transmitter about which subset is optimal and should thus be used by the mobile. In LTE, this is accomplished by employing a unique masking technique on the downlink control channel that eliminates the feedback overhead at the expense of a minor increase in complexity at the mobile. This article provides an in-depth and systematic overview of all physical and higher layer features in the LTE standard that enable TAS. Also highlighted are the variety of technical and standardization challenges that drove the specification of AS in LTE, and the aspects of the LTE standard that are impacted by AS. View full abstract»

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    LTE-WiFi Link Aggregation at Femtocell Base Station

    Kojima, Yuji ; Suga, Junichi ; Kawasaki, Takeshi ; Okuda, Masato ; Takechi, Ryuichi
    WTC 2014; World Telecommunications Congress 2014; Proceedings of

    Publication Year: 2014 , Page(s): 1 - 6

    VDE Conference Publications

    In this paper, we propose the architecture and an algorithm of LTE-WiFi Link Aggregation (LA) provided by an LTE femtocell base station. The link aggregation simultaneously uses both an LTE link and a WiFi link in order to improve the throughput of an IP traffic flow. Our proposed LA architecture is transparent to any application and supports multiple PDN (Packet Data Network) connections for a mobile operator's Evolved Packet Core (EPC) and Local IP Access (LIPA) in a home network. For the above purposes, any application transmits/receives IP packets to/from an LA control module in a terminal via two virtual network layer device TUNs, for EPC and LIPA. Our proposed LA algorithm distributes a TCP traffic flow to LTE and WiFi links based on the Modulation and Coding Scheme (MCS) and Physical Resource Block (PRB) usage of the LTE link. We have shown in an experimental evaluation that the TCP traffic flows to PC and Android terminals make use of the available bandwidth of LTE and WiFi links by using our proposed algorithm. View full abstract»

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    Application of LTE to wireless sensor systems

    Beale, M.W. ; Barrett, S.J. ; Piggin, P.W. ; Young, P.A. ; Morioka, Y.
    Wireless Sensor Systems (WSS 2012), IET Conference on

    DOI: 10.1049/cp.2012.0603
    Publication Year: 2012 , Page(s): 1 - 5
    Cited by:  Papers (2)

    IET Conference Publications

    Wireless sensors may be connected directly to a cellular network. The power consumption and cost of these cellular devices need to be minimised. Sensors typically create small infrequent datagrams. A 3GPP Long Term Evolution (LTE) network needs to communicate many signalling messages in order to transfer these datagrams. This paper presents some novel techniques to reduce the power consumption and cost of LTE devices and to reduce the signalling associated with supporting sensor systems over an LTE network. View full abstract»

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    An efficient implementation of PRACH generator in LTE UE transmitters

    Ying He ; Jian Wang ; Yongtao Su ; Dutkiewicz, E. ; Xiaojing Huang ; Jinglin Shi
    Wireless Communications and Mobile Computing Conference (IWCMC), 2011 7th International

    DOI: 10.1109/IWCMC.2011.5982775
    Publication Year: 2011 , Page(s): 2226 - 2230
    Cited by:  Papers (3)

    IEEE Conference Publications

    An efficient hardware-optimized Physical Random Access Channel (PRACH) baseband signal generation algorithm and its ASIC implementation in the LTE user equipment (UE) transmitter are presented in this paper. A simplified DFT of the Zadoff-Chu (ZC) sequence as well as a phase computation are applied to the prime size DFT of the PRACH preamble and the large size IDFT is accomplished by groups of smaller size IFFTs. The optimized algorithm achieves significantly lower computational complexity compared with the original algorithm in the LTE specification and better performance compared to another publication. The ASIC architecture is also designed to reduce the memory size and logic complexity, which achieves a low hardware cost in terms of the cell area. The proposed design was implemented in 65nm CMOS and it was demonstrated that this design can satisfy the timing requirements of the LTE specification. View full abstract»

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    Re-authentication protocol from WLAN to LTE (ReP WLAN-LTE)

    Othmen, S. ; Zarai, F. ; Obaidat, M.S. ; Belghith, A.
    Global Communications Conference (GLOBECOM), 2013 IEEE

    DOI: 10.1109/GLOCOM.2013.6831277
    Publication Year: 2013 , Page(s): 1446 - 1451

    IEEE Conference Publications

    Different wireless technologies have been standardized and commercialized, but none of these technologies is considered the best because each one has its own advantages and disadvantages. For example, Wireless Local Area Network (WLAN) offers bit rates surpassing those of Third generation (3G), but is found lacking with respect to roaming, mobility support and lack of sufficient security measures and architecture beyond basic radio access. Hence, inter-working between heterogeneous wireless networks is important to combine their best features and achieve the optimal in wireless communications. Security in inter-working is a major challenge due to the difference of security architectures between these wireless technologies. Therefore, several authentication protocols have been proposed to improve security such as Extensible Authentication Protocol for 3rd generation Authentication and Key Agreement (EAP-AKA) protocol which is used in 3G mobile networks to authenticate to non-cellular networks such as WLANs. In this paper, we analyze threats and attacks of this standard and we propose a re-authentication protocol from WLAN to LTE (ReP WLAN-LTE). This proposed solution allows a mobile connected to a WLAN to migrate to a LTE network. Moreover, it provides perfect forward secrecy to guarantee stronger security, mutual authentication, and resistance to replay attack. Through extensive simulation experiments, we found out that our proposed protocol presents optimal values for handoff latency and satisfactory loss rates, which meet the need for the quality of services. View full abstract»

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    Impact of relay station positioning on LTE uplink performance at flow level

    te Hennepe, D.H. ; van den Berg, J.L. ; Karagiannis, G.
    Global Communications Conference (GLOBECOM), 2012 IEEE

    DOI: 10.1109/GLOCOM.2012.6503340
    Publication Year: 2012 , Page(s): 1586 - 1592

    IEEE Conference Publications

    Long Term Evolution (LTE) is the latest cellular system that is being standardized by the 3rd Generation Partnership Project (3GPP) and is expected to substantially improve end-user throughput and reduce user plane latency, while at the same time significantly improve user experience with full mobility. To realize these expectations, 3GPP is investigating the relay station (RS) usage in LTE networks, which is an intermediate station placed between a Mobile Station (MS) and evolved Node-Bs (eNode-Bs). The RS positioning is an important factor that severely influences the LTE uplink performance. This paper analyses the impact of RS positioning on the LTE uplink performance at flow level by using numerical and simulation experiments. View full abstract»

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    Measurement characteristics of LTE-MIMO antenna for 4 G mobile handy terminal

    Chan-Jin Park ; Dea-Hwan Park ; Kyeong-Sik Min ; Jeong-Won Kim ; In-Hwan Kim
    Antennas and Propagation (ISAP), 2012 International Symposium on

    Publication Year: 2012 , Page(s): 523 - 526

    IEEE Conference Publications

    This paper presents measurement characteristics of LTE-MIMO antenna for 4 G mobile handy terminal. The considered LTE band is the class 13 and 14 in this research. Main antenna is operated reconfigurable by voltage control. The measured bandwidth of proposed antenna has been observed about 53 MHz (746~798 MHz) for VSWR 3:1. The measured isolation between main antenna and sub antenna has been showed about - 13 dB below at LTE band. View full abstract»

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    A QoE preserving M2M-aware hybrid scheduler for LTE uplink

    Abdalla, I. ; Venkatesan, S.
    Mobile and Wireless Networking (MoWNeT), 2013 International Conference on Selected Topics in

    DOI: 10.1109/MoWNet.2013.6613808
    Publication Year: 2013 , Page(s): 127 - 132

    IEEE Conference Publications

    The 4th Generation (4G) Long Term Evolution (LTE) wireless networks are expected to be used for the majority of Machine to Machine (M2M) communication. M2M communication over 4G networks faces some challenges. The main challenge is how to accommodate the massive number of M2M devices without negatively impacting the human subscribers' Quality of Experience (QoE). This paper discusses the challenges of scheduling UEs and M2M terminals in LTE networks. The LTE scheduler plays an important role in distributing radio resources to user equipments (UEs) and M2M terminals. We present a hybrid uplink scheduler that balances the radio resources allocation to preserve human users QoE and fairly fulfills M2M terminals communication requests. The simulation results show that the proposed solution provides fair scheduling of M2M terminals without impacting the UE. View full abstract»

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    Analyzing the security techniques used in LTE Advanced and their evaluation

    Rasheed, I. ; Amin, A. ; Chaudhary, M. ; Bukhari, S. ; Rizwan, M. ; Ali, K.
    Digital Information Management (ICDIM), 2013 Eighth International Conference on

    DOI: 10.1109/ICDIM.2013.6694004
    Publication Year: 2013 , Page(s): 11 - 13

    IEEE Conference Publications

    In this paper we discuss about security which is the main element in the wireless communication. As the generation changes many steps are used to improve the security so in this we discuss many security techniques choose, implement and compare two of them which provide better security to customers in LTE Advanced. LTE Advanced is evolved and advanced version of LTE (Long Term Evolution) which is developed by 3GPP. We implement the security techniques which we can use in LTE Advanced. To secure our data we use security algorithms (KASUMI & TDES) which have two parts encryption and decryption. In encryption process we convert our original data in cipher text by using keys and then transmit this encrypted data to the receiver. And at the receiving end we decrypt the encrypted data with the same keys to recover the original data. KASUMI Algorithm is a block cipher that produces a 64-bit output from 64-bit input under the control of a 128-key and three functions. It has 8 rounds. TDES Algorithm is a block cipher that produces a 64-bit output from a 64-bit input under the control of three keys of 64-bits with a function. It has 16 rounds. We implement these techniques in Matlab for verifying our results, and then we conclude that both algorithms are efficient for security purposes, so that no one can crack our data. View full abstract»

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    Scheduling policies based on dynamic throughput and fairness tradeoff control in LTE-A networks

    Comsa, I.S. ; Aydin, M. ; Sijing Zhang ; Kuonen, P. ; Wagen, J.-F. ; Yao Lu
    Local Computer Networks (LCN), 2014 IEEE 39th Conference on

    DOI: 10.1109/LCN.2014.6925806
    Publication Year: 2014 , Page(s): 418 - 421

    IEEE Conference Publications

    In LTE-A cellular networks there is a fundamental trade-off between the cell throughput and fairness levels for preselected users which are sharing the same amount of resources at one transmission time interval (TTI). The static parameterization of the Generalized Proportional Fair (GPF) scheduling rule is not able to maintain a satisfactory level of fairness at each TTI when a very dynamic radio environment is considered. The novelty of the current paper aims to find the optimal policy of GPF parameters in order to respect the fairness criterion. From sustainability reasons, the multi-layer perceptron neural network (MLPNN) is used to map at each TTI the continuous and multidimensional scheduler state into a desired GPF parameter. The MLPNN non-linear function is trained TTI-by-TTI based on the interaction between LTE scheduler and the proposed intelligent controller. The interaction is modeled by using the reinforcement learning (RL) principle in which the LTE scheduler behavior is modeled based on the Markov Decision Process (MDP) property. The continuous actor-critic learning automata (CACLA) RL algorithm is proposed to select at each TTI the continuous and optimal GPF parameter for a given MDP problem. The results indicate that CACLA enhances the convergence speed to the optimal fairness condition when compared with other existing methods by minimizing in the same time the number of TTIs when the scheduler is declared unfair. View full abstract»

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    An efficient downlink packet scheduling algorithm for real time traffics in LTE systems

    Bin Liu ; Hui Tian ; Lingling Xu
    Consumer Communications and Networking Conference (CCNC), 2013 IEEE

    DOI: 10.1109/CCNC.2013.6488471
    Publication Year: 2013 , Page(s): 364 - 369

    IEEE Conference Publications

    Long term evolution (LTE) represents new technological advance, which is conceived to significantly boost cellular network performance of real time services. However, scheduling algorithms that support real time applications have not been defined in the third generation partnership project (3GPP) specifications. In this paper a packet scheduling scheme with low complexity based on Earliest Deadline First (EDF) and Proportion Fair (PF) algorithm is proposed to enhance the Quality of Service (QoS) for real time traffics such as video and VoIP in LTE downlink system and we call it Modified EDF-PF (M-EDF-PF). System level simulations are conducted to verify the efficiency of M-EDF-PF. Numerical results demonstrate that the proposed M-EDF-PF scheduling algorithm can achieve obvious performance improvement for real time flows in LTE downlink system. The performance of the packet scheduling algorithm is evaluated based on traffic flow throughput, packet loss ratio (PLR), packet delay, fairness index, and cell spectral efficiency. View full abstract»

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    Handover in the 3GPP long term evolution (LTE) systems

    Jihai Han ; Bingyang Wu
    Mobile Congress (GMC), 2010 Global

    DOI: 10.1109/GMC.2010.5634584
    Publication Year: 2010 , Page(s): 1 - 6
    Cited by:  Papers (9)

    IEEE Conference Publications

    One of the main goals of E-UTRAN is to provide seamless access to voice and multimedia services with strict delay requirements, which is achieved by supporting handover from source cell to target cell. Proper handover algorithms can make the system increased capacity, better coverage, higher throughput, reduced latency requirements. In this paper we give an overview of the LTE intra-access handover procedure, the simulation approach, and several latest handover algorithms which can enhance performance of the LTE systems are introduced. Finally the results show that the handover in the LTE system is complicated and imperfect, proper handover algorithms in the LTE system should be researched as quickly as possible. View full abstract»

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    An Improved Rate Matching Algorithm for 3GPP LTE Turbo Code

    Long Yu ; Xu Wang ; Jian Liu
    Communications and Mobile Computing (CMC), 2011 Third International Conference on

    DOI: 10.1109/CMC.2011.93
    Publication Year: 2011 , Page(s): 345 - 348
    Cited by:  Papers (4)

    IEEE Conference Publications

    Long Term Evolution (LTE) describes the standardization work by the Third Generation Partnership Project (3GPP) to define a new high-speed radio access method for mobile communications systems. Rate Matching (RM) is an essential component in the adaptive coding rate system and has a great impact on the error correcting performance in turbo code system for 3GPP LTE. In this paper, we propose an efficient RM algorithm based on the circular buffer and interlaced puncturing applying to the 3GPP LTE system. More specifically, both system-parity cross output model of turbo code and puncturing parity bits preferentially pattern in the bit collection and puncturing process are introduced to obtain more stable performance in this RM algorithm. The simulation results indicate that the proposed algorithm can effectively improve the bit error ratio (BER) performance, especially at high code rate conditions, compared with traditional algorithm in LTE turbo code. View full abstract»

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    Design and simulation of TD-LTE dual-mode mobile terminal antenna combined with MIMO technology

    Xuanxuan Wang ; Wenxiu Wang ; Dan Shi ; Yougang Gao
    Environmental Electromagnetics (CEEM), 2012 6th Asia-Pacific Conference on

    DOI: 10.1109/CEEM.2012.6410562
    Publication Year: 2012 , Page(s): 46 - 49

    IEEE Conference Publications

    with the developing trend of the mobile terminal globalization, multi-standard coexistence mobile communication terminal will play an increasingly importance on the everyday lives of the people. TD-LTE is the TD-SCDMA subsequent evolution technology, which is one of the third generation (3G) international communication standard technologies defined proposed by China and has been widely accepted and approved by other countries in the international, and is also widely considered in the forth generation (4G) mobile communication. MIMO technology, which utilizes multiple antenna to improve spectrum efficiency and increase the system channel capacity, is one of the 4G key technologies. In the basis of the wide deployment and application of the TD-LTE and TD-SCDMA networks, the paper puts forward a design of TD-LTE dual-mode mobile communication terminal system combined with MIMO technology in the 2.57-2.62GHz frequency band. The proposed MMO antenna system consists of two meander line monopole. They are designed to be bent opposite to one another to reduce the mutual coupling. The TD-SCDMA (1.8-2.4GHz) antenna system is based on the PIFA antenna structure, with the “inverted F” removed from the upper surface. To achieve a good matching, a rectangle sheet with size of 44.0mm×15.0mm on the full ground plane is removed. In addition, the effects of parameters between MIMO antennas and TD-SCDMA antenna are studied by using Ansoft High Frequency Structure Simulation (HFSS). On the basis of the simulated results, the proposed system has the isolation of 26.7dB at the central frequency of 2.6 GHz, the antenna gain improves to 6.34dB and the antenna radiation efficiency can reach to 98.12%. The design provides a favorable reference for TD-LTE dual-mode mobile terminal. View full abstract»

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    Modeling and event-driven simulation of coordinated multi-point joint transmission in LTE-advanced with constrained backhaul

    Artuso, M. ; Christiansen, H.L.
    Simulation Conference (WSC), 2014 Winter

    DOI: 10.1109/WSC.2014.7020150
    Publication Year: 2014 , Page(s): 3131 - 3142

    IEEE Conference Publications

    Inter-cell interference (ICI) is considered as the most critical bottleneck to ubiquitous 4th generation cellular access in the mobile long term evolution (LTE). To address the problem, several solutions are under evaluation as part of LTE-Advanced (LTE-A), the most promising one being coordinated multi-point joint transmission (CoMP JT). Field tests are generally considered impractical and costly for CoMP JT, therefore the need to provide a comprehensive and high-fidelity computer model to understand the impact of different design attributes and the applicability use cases. This paper presents a novel approach to the modelling and simulation of an LTE-A system with CoMP JT by means of discrete event simulation (DES) using OPNET modeler. Simulation results are provided for a full buffer traffic model and varying the characteristics of the interface between cooperating points. Gains of up to 120% are achieved for the system throughput when using CoMP JT. View full abstract»

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    Backhauling solutions for LTE networks

    Lometti, A. ; Addeo, C. ; Busi, I. ; Sestito, V.
    Transparent Optical Networks (ICTON), 2014 16th International Conference on

    DOI: 10.1109/ICTON.2014.6876351
    Publication Year: 2014 , Page(s): 1 - 6

    IEEE Conference Publications

    LTE and LTE advanced mobile technologies impose quite new requirements to backhauling network and may call for revolutionary approaches, like fronthauling, in order to exploit the full potential of the technology. In this paper we synthesize main requirements for LTE and LTE advanced backhauling and fronthauling, along with the underlining rationale, and describe to some extent possible different network designs, both at L1 (fronthauling) and L2 / L3 (backhauling), comparing them against those requirements. View full abstract»

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    QoS-enabled group communication in integrated VANET-LTE heterogeneous wireless networks

    Sivaraj, R. ; Gopalakrishna, A.K. ; Chandra, M.G. ; Balamuralidhar, P.
    Wireless and Mobile Computing, Networking and Communications (WiMob), 2011 IEEE 7th International Conference on

    DOI: 10.1109/WiMOB.2011.6085417
    Publication Year: 2011 , Page(s): 17 - 24
    Cited by:  Papers (3)

    IEEE Conference Publications

    Ubiquitous integration of high-speed WLANs with wide-range 3GPP systems results in the service extension of the backbone cellular network. This paper envisions such heterogeneous wireless network architecture by integrating IEEE 802.11p VANETs with 3GPP LTE to achieve seamless data connectivity for uninterrupted multimedia sessions amongst spatially-apart vehicular clusters. Issues on cluster head-based multicasting and QoS are explored in this paper. An adaptive multi-metric Cluster Head (CH) election mechanism is proposed to manage the VANET sub-clusters. In addition to this, construction of a 2-hop virtual overlay mesh-based shared multicast tree for lower-level multicasting within VANETs is discussed. Following this, the process of VANET-LTE upper-level communication is detailed, addressing the issues of CH and gateway handover, and resource allocation of the LTE eNB. The envisioned architecture enables the LTE to effectively schedule multimedia sessions based on the service requirements of the VANET gateways, thus satisfying QoS. Requisite simulation results are presented to evaluate the integrated network. View full abstract»

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    CR Enabled TD-LTE within TV White Space: System Level Performance Analysis

    Junfeng Xiao ; Feng Ye ; Tingjian Tian ; Hu, R.Q.
    Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE

    DOI: 10.1109/GLOCOM.2011.6133923
    Publication Year: 2011 , Page(s): 1 - 6
    Cited by:  Papers (3)

    IEEE Conference Publications

    Cognitive Radio has emerged as a new technology to improve spectrum utilization and to alleviate spectrum scarcity by allowing unlicensed users to sense and opportunistically access the under-utilized spectrum. This paper proposes a system framework for the Cognitive Radio enabled TD-LTE system that opportunistically accesses and utilizes the TV White Space spectrum. The system performance of both TV broadcasting network and TD-LTE network is evaluated and analyzed. The simulation studies show that the proposed framework can significantly improve the performance of both TV and TD-LTE systems when they are co-operating within the same TV spectrum with TV as the primary user and TD-LTE as the secondary user. Both TV spectrum utilization and TD-LTE coverage are greatly enhanced. View full abstract»

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    Performance of Authentication Protocols in LTE Environments

    Lianfen Huang ; Ying Huang ; Zhibin Gao ; Jianan Lin ; Xueyuan Jiang
    Computational Intelligence and Security, 2009. CIS '09. International Conference on

    Volume: 2
    DOI: 10.1109/CIS.2009.50
    Publication Year: 2009 , Page(s): 293 - 297
    Cited by:  Papers (4)

    IEEE Conference Publications

    Long-Term Evolution (LTE) is the next-generation network beyond 3G. Authentication service is one of the most essential services in LTE networks, which has significant effects on internet security. In this paper, we survey and compare three authentication protocols: Password Authentication Protocol, Lightweight Extensible Authentication Protocol, and Extensive Authentication Protocol-Transport Layer Security. We present our implementation approach for the LTE testbed. From the experimental results, we conclude that PAP and LEAP are not sufficiently secure due to their vulnerability to dictionary attacks, while EAP-TLS can provide robust security if the network users are not very concerned with the overhead. Our proposed LTE testbed is meaningful and can be used to test the efficiency of other protocols. View full abstract»

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    Interference Estimation of Analog TV and LTE System Based on Cognitive Radio

    Mingxing Liu ; Wenwen Ma
    Broadband and Wireless Computing, Communication and Applications (BWCCA), 2014 Ninth International Conference on

    DOI: 10.1109/BWCCA.2014.103
    Publication Year: 2014 , Page(s): 458 - 461

    IEEE Conference Publications

    The paper mainly discusses the interference between LTE system and Analog TV in the frequency band 700MHz, with the simulation of the interference probability caused by the LTE cell based on energy detection of cognitive radio. The formula of interference distribution is based on RSMN network model, and focuses on the interference probability changed with the distance between LTE cell and Analog TV as well as the radius of LTE cell. That is, we can minimize effect of the interference to a certain extent by adjusting the parameters above. View full abstract»

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    LTE eNodeB prototype based on GPP platform

    Niu Kai ; Sun Jianxing ; He Zhiqiang ; Kok Keong Chai
    Globecom Workshops (GC Wkshps), 2012 IEEE

    DOI: 10.1109/GLOCOMW.2012.6477583
    Publication Year: 2012 , Page(s): 279 - 284
    Cited by:  Papers (1)

    IEEE Conference Publications

    This paper presents a real-time LTE signal processing system based on general purpose processor (GPP) platform. LTE is one of the wideband wireless communication systems with strict requirements of performance and real-time. To meet these requirements, high-efficiency implementation methods such as SIMD instructions and multicore processing are applied to the system for accelerating the processing. Finally, we achieved an effective LTE eNodeB prototype on commodity PC platform with a low processing latency. The prototype supports most functions of MAC and PHY and reveals the feasibility of realizing real-time high-throughput signal processing systems based on GPP platform. View full abstract»

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    MIMO performance study of different antennas for LTE mobile phones in CTIA test mode

    Kun Zhao ; Shuai Zhang ; Zhinong Ying ; Sailing He
    Antennas and Propagation (EuCAP), 2013 7th European Conference on

    Publication Year: 2013 , Page(s): 727 - 731

    IEEE Conference Publications

    This paper reports a study of body loss for LTE MIMO antennas in mobile phones with the effects of different mobile phone lengths. Two designs of dual elements MIMO antenna (dual Semi PIFA and co-located antenna) are studied under two typical LTE and mobile phone frequency points (0.85GHz and 1.9 GHz) with three mobile phone lengths (110mm, 130mm and 150mm). And the performance of correlation and multiplex efficiency are also evaluated. The simulations are carried out on talking position in CTIA standard. In order to verify the simulation results, the measurements for the dual semi PIFA are carried out as well. The analysis for the results provides novel and useful information for the design of LTE MIMO antennas in mobile phones for body loss optimization. View full abstract»

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    Analysis of CQI Prediction for MU-MIMO in LTE Systems

    Badic, B. ; Balraj, R. ; Scholand, T. ; Bai, Z. ; Iwelski, S.
    Vehicular Technology Conference (VTC Spring), 2012 IEEE 75th

    DOI: 10.1109/VETECS.2012.6240035
    Publication Year: 2012 , Page(s): 1 - 5
    Cited by:  Papers (2)

    IEEE Conference Publications

    The aim of this paper is to get an insight of multiuser multiple-input and multiple-output (MU-MIMO) channel quality indicator (CQI) prediction for long term evolution (LTE) systems. MU-MIMO CQI predictions have been investigated for LTE Release 8 (rank one, Transmission Mode 5) and for LTE Release 9 (adaptive rank, Transmission Mode 8) at the link level. The relationship between CQI reporting and channel conditions is analytically analysed and demonstrated. The tradeoff between the performance gain and the feedback overhead w.r.t. MUMIMO CQI prediction is investigated as well. The results have shown how MU-MIMO CQI prediction is influenced by channel correlation and that significant improvements can be achieved through rank adaption and receiver choice. The results have also shown the potentially most efficient system configuration (feedback design and CQI prediction scheme) to facilitate MUMIMO transmission for practical LTE systems. View full abstract»

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    Surrogate Based Centralized Automated Optimization Applied to LTE Mobility Load Balancing

    Khan, Y. ; Sayrac, B. ; Moulines, E.
    Vehicular Technology Conference (VTC Fall), 2013 IEEE 78th

    DOI: 10.1109/VTCFall.2013.6692427
    Publication Year: 2013 , Page(s): 1 - 5
    Cited by:  Papers (2)

    IEEE Conference Publications

    Deployment of Long Term Evolution (LTE) amp; LTE- Advanced networks will be challenged by cost and complexity. Self Organizing Network (SON) functionalities promise significant improvement of the network in terms of reducing OPerational EXpenditure (OPEX) and performance improvement. In this paper, we propose a recursive automated optimization method which builds statistical models of the functional relationships between noisy Key Performance Indicators (KPIs) and network parameters; and performs stochastic optimization during the model building process. The proposed methodology is applied to a centralized intra-LTE Mobility Load Balancing (MLB) problem and its performance is evaluated through system level simulations. The results show that the proposed modeling and optimization approach is a promising solution for centralized intra-LTE MLB in terms of optimization performance and convergence under noisy data. View full abstract»

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    Efficient Frequency Domain Packet scheduler for Point-to-Multipoint transmissions in LTE networks

    Araniti, G. ; Scordamaglia, V. ; Condoluci, M. ; Molinaro, A. ; Iera, A.
    Communications (ICC), 2012 IEEE International Conference on

    DOI: 10.1109/ICC.2012.6364383
    Publication Year: 2012 , Page(s): 4405 - 4409
    Cited by:  Papers (6)

    IEEE Conference Publications

    Long Term Evolution (LTE) is the emerging 4G wireless technology developed to provide high quality services in mobile environments. It is foreseen that multimedia services and mobile TV will assume an important role for the LTE proliferation in mobile market. However, several issues are still open and meaningful improvements have to be introduced for managing physical resources when group-oriented services should be supplied. To this end, we propose a Frequency Domain Packet Scheduling (FDPS) algorithm for efficient radio resource management of Multimedia Broadcast/Multicast Services (MBMS) in LTE networks. The proposed scheduler exploits an optimization process to organize multicast subscribers in subgroups according to channel quality feedbacks provided by users. Optimization is driven by the aim of minimizing the “user dissatisfaction” with a consequent improvement in the network capacity. The effectiveness of the proposed scheduling algorithm is evaluated through simulation; obtained results demonstrate significant improvement in the multicast traffic performance. View full abstract»

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    Policies and technology constraints for auctions in TV white spaces - A practical approach for LTE-A

    Parzy, M. ; Bogucka, H.
    Wireless Communication Systems (ISWCS), 2012 International Symposium on

    DOI: 10.1109/ISWCS.2012.6328523
    Publication Year: 2012 , Page(s): 1024 - 1028
    Cited by:  Papers (2)

    IEEE Conference Publications

    In this paper we consider the auction approach for cognitive spectrum usage by mobile radio systems, in particular TV white spaces (TVWS) spectrum auctions for LTE and its extension LTE-A. Our auction model considers the nature of TVWS, such as the variety of the allowable transmit power, spectrum fragmentation, and its time availability, as well as various spectrum market characteristics, the nature of potential market participants, regulatory aspects and technology constraints. The impact of these aspects is considered in the proposed auction mode which proposes medium-term combinatorial auction of heterogeneous objects defined by frequency bandwidth and power constraints. Simultaneous auction in time domain is also considered, which allows for reaching the maximum efficiency in terms of the spectrum sold and the achieved auctioneer's profit. The auction is organized in independent areas by the centralized spectrum broker. View full abstract»

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    Implementation trade-offs of fountain codes in LTE and LTE-A

    Hamdoun, H. ; Loskot, P. ; O'Farrell, T.
    Communications and Networking in China (CHINACOM), 2012 7th International ICST Conference on

    DOI: 10.1109/ChinaCom.2012.6417519
    Publication Year: 2012 , Page(s): 419 - 424
    Cited by:  Papers (1)

    IEEE Conference Publications

    The fountain codes are attractive for efficient multicast delivery of large data or multimedia files over unreliable wireless channels. These codes are standardized and intended to operate at the application layer. In this paper, the fountain codes are incorporated into the LTE protocol stack at the medium access (MAC) layer. It is shown that the MAC layer implementation of the fountain codes requires that not only the LTE parameters are optimized, but also, that the adaptive modulation and coding (AMC) scheme mechanism is modified. Provided that such optimization and modifications are adopted, for instance, in the LTE-Advanced, the MAC layer fountain codes can significantly outperform the application layer fountain codes in terms of the energy consumption-transmission delay trade-off. View full abstract»

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    LTE PHY performance analysis under 3GPP standards parameters

    Rezaei, F. ; Hempel, M. ; Sharif, H.
    Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), 2011 IEEE 16th International Workshop on

    DOI: 10.1109/CAMAD.2011.5941095
    Publication Year: 2011 , Page(s): 102 - 106
    Cited by:  Papers (6)

    IEEE Conference Publications

    Long Term Evolution (LTE) has been introduced by 3GPP (3rd Generation Partnership Project) and is poised to dominate the 4th generation (4G) of mobile telecommunication networks. In this article, we present an in-depth analysis of the LTE physical layer's characteristics and its performance. Our work is unique in providing a detailed performance study based on Release 8 of the 3GPP standard. Several works have discussed the LTE performance; however, most have been restricted to limited scenarios. Our work shows a more comprehensive investigation of the maximum data throughput under different conditions and scenarios. Our performance study includes TDD and FDD operational modes for uplink and downlink transmissions in different antenna diversity schemes, data modulation, and code rates. Our results show that LTE (3GPP-Release 8) supports downlink throughputs of up to 300Mbps and for the uplink a throughput of up to 75 Mbps. View full abstract»

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    Uplink burst LTE-A signal transmission on a converged millimeter-wave and RoF system

    Dat, P.T. ; Kanno, A. ; Kawanishi, T.
    Microwave Photonics (MWP) and the 2014 9th Asia-Pacific Microwave Photonics Conference (APMP), 2014 International Topical Meeting on

    DOI: 10.1109/MWP.2014.6994477
    Publication Year: 2014 , Page(s): 13 - 16

    IEEE Conference Publications

    We propose a high-speed uplink burst-mode LTE-A signal transmission on a converged millimeter-wave and radio-over-fiber system. By using a newly developed burst-mode optical amplifier, we successfully transmit an uplink 5-carrier component LTE-A signal over a converged 5-m 92.5-GHz wireless link and 20-km radio-over-fiber system. View full abstract»

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    A policy based conflict resolution mechanism for MLB and MRO in LTE self-optimizing networks

    Zia, N. ; Mwanje, S.S. ; Mitschele-Thiel, A.
    Computers and Communication (ISCC), 2014 IEEE Symposium on

    DOI: 10.1109/ISCC.2014.6912543
    Publication Year: 2014 , Page(s): 1 - 6

    IEEE Conference Publications

    Mobility Load Balancing (MLB) and Mobility Robustness Optimization (MRO) are two major SON (Self-Organizing Network) use cases specified for LTE (Long Term Evolution) by 3GPP (3rd Generation Partnership Project). MRO targets at optimizing the handover (HO) performance of the network by adjusting the HO point. Whereas, MLB reduces the congestion in traffic hotspots by advancing HOs from overloaded hotspot cells to less loaded neighbor cells. However, MLB degrades HO performance of the network because advanced HOs lead to worse SINR (Signal-to-Interference plus Noise Ratio) conditions with the target cells as compared to the original HO point. Hence, MLB can trigger MRO to optimize the HO performance and MRO can in turn trigger MLB to adjust the HO point for advanced HOs. Resultantly, MLB and MRO working in parallel can lead to oscillations. In this paper we present a policy based mechanism, termed as MLB-Static, which exploits users' mobility state to minimize the impact of MLB on HO performance and hence prevents oscillations. The simulation results, for a hexagonal LTE macro cellular deployment, show that MLB-Static has negligible impact on HO performance of the network as compared to conventional MLB while the gain of conventional MLB is preserved by MLB-Static. View full abstract»

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    Performance evaluation of ICN/CCN based service migration approach in virtualized LTE systems

    Satria, T.A. ; Karimzadeh, M. ; Karagiannis, G.
    Cloud Networking (CloudNet), 2014 IEEE 3rd International Conference on

    DOI: 10.1109/CloudNet.2014.6969038
    Publication Year: 2014 , Page(s): 461 - 467

    IEEE Conference Publications

    The continuous growth in using mobile devices (e.g. smart phones, tablets, etc.) has increased the complexity in provisioning cellular network resources. Applying the cloud computing model in LTE (Long Term Evolution) systems could be a good solution to increase LTE's performance by building a shared distributed mobile network that can optimize the utilization of resources, minimize communication delays, and avoid bottlenecks. One of the most important concepts used in mobile networks is service continuity. Mobile users moving from one sub-network to another should be able to seamlessly continue to retrieve content and use services (e.g. video streaming, electronic games, VoIP, etc.) that they want. In this paper, the Information Centric Networking/Content Centric Networking (ICN/CCN) approach is proposed to be used as a solution for service continuity in virtualized LTE systems. By using NS3 simulation experiments it is shown that the introduced approach is able to satisfy the performance related service continuity requirements. View full abstract»

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    Improving third-party relaying for LTE-A: A realistic simulation approach

    Gomez-Cuba, F. ; Gonzalez-Castano, F.J.
    Communications (ICC), 2014 IEEE International Conference on

    DOI: 10.1109/ICC.2014.6883673
    Publication Year: 2014 , Page(s): 2344 - 2350

    IEEE Conference Publications

    In this article we propose solutions to diverse conflicts that result from the deployment of the (still immature) relay node (RN) technology in LTE-A networks. These conflicts and their possible solutions have been observed by implementing standard-compliant relay functionalities on the Vienna simulator. As an original experimental approach, we model realistic RN operation, taking into account that transmitters are not active all the time due to half-duplex RN operation. We have rearranged existing elements in the simulator in a manner that emulates RN behavior, rather than implementing a standalone brand-new component for the simulator. We also study analytically some of the issues observed in the interaction between the network and the RNs, to draw conclusions beyond simulation observation. The main observations of this paper are that: i) Additional time-varying interference management steps are needed, because the LTE-A standard employs a fixed time division between eNB-RN and RN-UE transmissions (typical relay capacity or throughput research models balance them optimally, which is unrealistic nowadays); ii) There is a trade-off between the time-division constraints of relaying and multi-user diversity; the stricter the constraints on relay scheduling are, the less flexibility schedulers have to exploit channel variation; and iii) Thee standard contains a variety of parameters for relaying configuration, but not all cases of interest are covered. View full abstract»

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    Power efficient uplink LTE with CPM-SC-IFDMA

    Rahman, R. ; Perrins, E. ; Green, M.
    MILITARY COMMUNICATIONS CONFERENCE, 2011 - MILCOM 2011

    DOI: 10.1109/MILCOM.2011.6127721
    Publication Year: 2011 , Page(s): 507 - 512

    IEEE Conference Publications

    Power efficiency represents a key concern in the mobile communication field. Poor power efficiency leads to shorter battery life and increases the cost of the mobile device. Improving power efficiency is more important for uplink transmission since in uplink the transmitter is placed in the battery-powered mobile device which has limited power resources. In this paper we propose a power efficient scheme, CPM-SC-IFDMA, for uplink transmission in LTE (Long Term Evolution). The proposed scheme, CPM-SC-IFDMA, combines the key advantages of CPM (continuous phase modulation) with SC-IFDMA (Single Carrier Frequency Division Multiple Access with Interleaved subcarrier mapping) in order to increase the power amplifier efficiency of the transmitter. In this work, we investigate the bit error rate (BER) performance of the proposed scheme in LTE specified channels. The BER performance of the CPM-SC-IFDMA scheme is compared with that of a LTE specified transmission scheme, QPSK-LFDMA (QPSK modulated SC-FDMA with localized subcarrier mapping), combined with convolutional coding (CC-QPSK-LFDMA). We first show that CPM-SC-IFDMA has a much higher power efficiency than CC-QPSK-LFDMA by simulating the PAPR (peak-to-average-power-ratio) plots. Then, using the data from the PAPR plots and the conventional BER plots (BER as a function of signal-to-noise-ratio), we show that, when compensated for power efficiency loss CPM-SC-IFDMA has a superior performance relative to CC-QPSK-LFDMA by up to 3.8 dB in the LTE specified channels. View full abstract»

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    4-bit Flash Analog to Digital Converter design using CMOS-LTE Comparator

    Kulkarni, M. ; Sridhar, V. ; Kulkarni, G.H.
    Circuits and Systems (APCCAS), 2010 IEEE Asia Pacific Conference on

    DOI: 10.1109/APCCAS.2010.5774817
    Publication Year: 2010 , Page(s): 772 - 775
    Cited by:  Papers (1)

    IEEE Conference Publications

    This paper proposes 4-bit, 1.8V Flash Analog to Digital Converter (ADC) design using CMOS-LTE (CMOS Linear Tunable Transconductance Element) Comparator with 500nm technology. Reference voltages are generated by systematically sizing the transistors of the comparators, thus completely eliminating the resistive ladder network required for the architecture. The PSRR (Power Supply Rejection Ratio) results obtained are compared with 4-bit TIQ (Threshold Inverter Quantizer) Comparator Flash Analog to Digital Converter designed with 500nm technology. It is observed that, with the use of CMOS-LTE Comparator PSRR is improved. The DC simulation results of CMOS-LTE Comparator ADC shows DNL and INL of +0.16/-0.16 LSB and +0.16/-0.104 LSB. The total power dissipation observed is 0.28753 mW. View full abstract»

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    Hybrid Current-Mode Class-S Power Amplifier With GaN Schottky Diode Using Chip-On-Board Technique for 955 MHz LTE Signal

    Jun-Chul Park ; Jong-Gwan Yook ; Bong Hyuk Park ; Namcheol Jeon ; Kwang-Seok Seo ; Dongsu Kim ; Woo-Sung Lee ; Chan-Sei Yoo
    Microwave Theory and Techniques, IEEE Transactions on

    Volume: 61 , Issue: 12 , Part: 1
    DOI: 10.1109/TMTT.2013.2288084
    Publication Year: 2013 , Page(s): 4168 - 4178
    Cited by:  Papers (1)

    IEEE Journals & Magazines

    This paper presents a gallium nitride (GaN)-based hybrid current-mode class-S (CMCS) power amplifier (PA) using a bandpass delta-sigma modulator (BPDSM) for a 955-MHz LTE signal. To enhance the drain efficiency of the CMCS PA, the chip-on-board (COB) technique, which can reduce the external parasitic components of the packaged transistor and allow fast switching operation at high frequencies by minimizing distortion of the pulse waveform, is adopted. Also, GaN Schottky barrier diodes are fabricated in-house to protect the switching transistor against the high negative voltage swing. The differential output filter and balun composed of lumped LC resonators are integrated at the back of the switching transistor to extract amplified LTE signal from the output rectangular waveform, and the fabricated CMCS PA is measured and analyzed at four different states of BPDSM according to the coding efficiency from different input power level to obtain higher power and efficiency. Finally, a cavity bandpass filter (BPF) is added to the output circuit for a more accurate reduction of the harmonics and out-of-band noise signals to enhance system efficiency. From the measured results for an 8.5-dB PAPR 3 G LTE 10-MHz input signal, the proposed CMCS PA has a maximum average output power of 37.61 and 30.78 dBm, and the resulting drain efficiencies of 33.3% and 38.6% with the drain voltage of 19 and 7 V, respectively. View full abstract»

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    High efficiency wideband envelope tracking power amplifier with direct current sensing for LTE applications

    Myoungbo Kwak ; Jinseong Jeong ; Hassan, M. ; Yan, J.J. ; Kimball, D.F. ; Asbeck, P.M. ; Larson, L.E.
    Power Amplifiers for Wireless and Radio Applications (PAWR), 2012 IEEE Topical Conference on

    DOI: 10.1109/PAWR.2012.6174933
    Publication Year: 2012 , Page(s): 41 - 44
    Cited by:  Papers (4)

    IEEE Conference Publications

    A high efficiency wideband envelope tracking power amplifier for LTE applications is presented. The CMOS envelope amplifier with direct current sensing has a measured average efficiency of 78% with a 5 MHz LTE signal. The envelope tracking power amplifier including a GaAs HBT RF stage has overall power added efficiency (PAE) above 46% with an average LTE output power of 27.6 dBm and a gain of 26.5 dB. View full abstract»

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    Cluster-Based Vehicular Data Collection for Efficient LTE Machine-Type Communication

    Ide, C. ; Kurtz, F. ; Wietfeld, C.
    Vehicular Technology Conference (VTC Fall), 2013 IEEE 78th

    DOI: 10.1109/VTCFall.2013.6692136
    Publication Year: 2013 , Page(s): 1 - 5

    IEEE Conference Publications

    Machine-Type Communication (MTC) poses an ongoing research topic in the development of cellular communication systems. In this context, the efficient collection of extended Floating Car Data (xFCD) via Long Term Evolution (LTE) is a major challenge. In this paper, we present cluster-based xFCD collection schemes in order to form clusters with a long lifetime. As a result, the proposed clustering algorithms reduce the occurring cellular communication traffic. For the performance evaluation of the presented algorithm, a novel system model is used. By means of the system model, the user mobility can be modeled realistically and a precise quantification of the utilization of the LTE network for xFCD transmission is possible. The results show that the LTE network utilization can be significantly reduced by the proposed clustering algorithms. View full abstract»

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    Cross layer scheduling algorithm for LTE downlink

    Avramova, A.P. ; Ying Yan ; Dittmann, L.
    Telecommunications Forum (TELFOR), 2012 20th

    DOI: 10.1109/TELFOR.2012.6419208
    Publication Year: 2012 , Page(s): 307 - 310

    IEEE Conference Publications

    The LTE standards is leading standard in the wireless broadband market. In order to accommodate the increased demand for mobile data services the radio interface in the LTE standard is enhanced with advanced technologies such as OFDMA (Orthogonal Frequency Division Multiple Access) and MIMO (multiple antenna) techniques. The Radio Resource Management at the base station plays major role in satisfying the users demand for high data rates and QoS. Resources for both downlink and uplink transmission need to be assigned such that the capacity, throughput, and cell edge performance are optimized. This paper evaluates a cross layer scheduling algorithm that aims at minimizing the resource utilization. The algorithm makes decisions regarding the channel conditions and the size of transmission buffers and different QoS demands. The simulation results show that the new algorithm improves the resource utilization as well as provides better guaranties for QoS. View full abstract»

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    A study of algorithm for LTE intra-frequency handover

    Yanbin Yuan ; Ziqing Chen
    Computer Science and Service System (CSSS), 2011 International Conference on

    DOI: 10.1109/CSSS.2011.5974650
    Publication Year: 2011 , Page(s): 1986 - 1989
    Cited by:  Papers (2)

    IEEE Conference Publications

    One of the main goals of LTE is to provide seamless access to voice and multimedia services with strict delay requirements, which is achieved by supporting effective handover algorithm from source cell to target cell. In this paper we first give an overview of the LTE architecture and the LTE intra frequency handover procedure .Secondly, we analysis the performance of A3 handover algorithm based on A3 Event from the handover failure rate. Then ,we propose a new handover algorithm which can reduce the pingpang handover compared to A3 algorithm. View full abstract»

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    Adaptive double thresholds handover mechanism in small cell LTE-A network

    Qiang Shen ; Jing Liu ; Zhangpeng Huang ; Xiaoying Gan ; Zhifeng Zhang ; Dong Chen
    Wireless Communications and Signal Processing (WCSP), 2014 Sixth International Conference on

    DOI: 10.1109/WCSP.2014.6992103
    Publication Year: 2014 , Page(s): 1 - 6

    IEEE Conference Publications

    Rapid demands for large capacity services and shortage spectrum resources have motivated the deployment of small cells in LTE-A network. Small cells are low-cost, low power nodes with limited coverage region, as the existence of small cells, more sophisticated network architecture increases the difficulty in dealing with mobility management. The contradiction between traffic demands and network resources is also very prominent, the rationally tradeoff between high quality service demands and signaling overhead in HO procedure should be considered in mobility management. Aiming at solving these issues, efficient handover (HO) mechanisms are more and more concerned to enhance mobility management in small cell networks. In this paper, we proposed a Self-Organizing Networks (SON) based Double Thresholds Optimization (DTO) handover algorithm, which offers an efficient method to mitigate handover signaling overhead while satisfying user's requirements of service quality. Specifically, through optimizing two key HO parameters associated with HO procedure, DTO enhances mobility robustness management effectively. Furthermore, a system-level LTE simulator is implemented to evaluate the mobility performance. The results strongly verify that the proposed DTO algorithm can assist LTE network in achieving an appropriate compromise between handover (HO) signaling overhead and quality of service (QoS), besides, load balance is acquired with rational allocation of resources. View full abstract»

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    On the performance of LTE-Advanced MIMO: How to set and reach beyond 4G targets

    Lahetkangas, Eeva ; Pajukoski, Kari ; Tiirola, Esa ; Hamalainen, Jyri ; Zhong Zheng
    European Wireless, 2012. EW. 18th European Wireless Conference

    Publication Year: 2012 , Page(s): 1 - 6

    VDE Conference Publications

    Standardization of 3GPP LTE-Advanced (LTE-A), also called as 4G, is continuing strongly. Yet, in parallel the discussion on performance targets for systems beyond 4G have been initiated in industry. The aim of this paper is to investigate the link level performance of LTE-A downlink (DL) when large antenna array MIMO is employed. The link level simulation results show very high user throughputs when employing e.g. 8x8 MIMO. Yet, the comparison between simulation results and known spectral efficiency bounds show that LTE-A performance is still quite far away from theoretical limits. Results also indicate that realistic beyond 4G peak rate target on link level can be set close to 10 Gbps provided that 8x8 MIMO and 256QAM are applied, and the operation bandwidth can be doubled from current 100MHz. The spatial correlation in both transmitter and receiver ends will reduce the performance. View full abstract»

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    Coordinated Beamforming Technology in TD-LTE-Advanced System

    Lin Hui ; Wang Wen Bo
    Communications and Mobile Computing (CMC), 2010 International Conference on

    Volume: 2
    DOI: 10.1109/CMC.2010.23
    Publication Year: 2010 , Page(s): 213 - 216
    Cited by:  Papers (2)

    IEEE Conference Publications

    As extension of MIMO technology in cellular system with multiple cell sites, Cooperative Network MIMO is a hot topic for the research of future wireless communication. In current study of TD-LTE-Advanced (LTE-Advanced TDD) system, various coordinated beamforming schemes have shown to be very promising candidates. In this paper we introduce a few implementations of coordinated beamforming technology with different levels of coordination, together with system level simulations and analysis. View full abstract»

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    UE performance evaluation on LTE indoor and outdoor testbeds

    Hung, J.-T.J. ; Chia-Yu Ku ; Hsiao-Chin Cheng ; Li-Ping Tung ; Lin, B.-S.P.
    Wireless and Pervasive Computing (ISWPC), 2013 International Symposium on

    DOI: 10.1109/ISWPC.2013.6707431
    Publication Year: 2013 , Page(s): 1 - 5

    IEEE Conference Publications

    As the ever increasing demands for higher data rate, lower system latency, and high speed in mobile communications, 4G/LTE systems widely deployed provide better support for these requirements. This increased the complexity of UE (user equipment) and eNBs (evolved Node B) structures, but with simplified core networks. A more flat architecture is achieved to raise data rate and low system latency that are appreciated by users using real-time or high throughput applications such as MAR (mobile augmented reality) or video game applications. The work introduces indoor and outdoor LTE (Long Term Evolution) testbeds for UE performance evaluation via IOT (interoperability) tests and field trials. Throughput for distinct UL-DL (uplink-downlink) configurations were measured to evaluate devices' performance. View full abstract»

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    LTE application and congestion performance

    Calin, D. ; Bong Ho Kim
    Bell Labs Technical Journal

    Volume: 18 , Issue: 1
    DOI: 10.1002/bltj.21590
    Publication Year: 2013 , Page(s): 5 - 25

    Alcatel-Lucent Journal

    The complexity of today's wireless networks and the new applications from smartphones call for an in-depth understanding of the mutual impact of networks and applications. We have created a unique Long Term Evolution (LTE) end-to-end network and application performance platform which fulfills several pre-identified needs: 1) to model an actual market so that when traffic models change one can quickly assess the overall impact to customers, 2) optimize products to achieve the best end user experience, 3) develop guidelines for network deployment and capacity analysis, and 4) understand and extend application performance results from the field and lab testing. In this paper we analyze and report the impact of thin traffic applications on the LTE network. In particular, we analyze the performance of underlying packet transmission protocols and the impact of machine-to-machine telemetry on the LTE control plane. We further propose a protocol enhancement to reduce the signaling load and packet transmission delays over a LTE network. View full abstract»

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    Investigation of Control Signaling and Reference Signal Design for Downlink MU-MIMO in LTE-Advanced

    Xiaoming She ; Taoka, H. ; Jianchi Zhu ; Lan Chen
    Vehicular Technology Conference (VTC Spring), 2011 IEEE 73rd

    DOI: 10.1109/VETECS.2011.5956240
    Publication Year: 2011 , Page(s): 1 - 6

    IEEE Conference Publications

    3rd Generation Partnership Project (3GPP) is specifying Long Term Evolution Advanced (LTE-A) targeting for higher average cell and cell-edge spectrum efficiency over LTE, and multi-user MIMO (MU-MIMO) is identified as a key technique to reach the International Mobile Telecommunication Advanced (IMT-A) performance requirements. In this paper, we present the investigation on the MU-MIMO enhancement issues in LTE-A mainly from the viewpoint of MU-MIMO transparency, i.e., necessity of indication of co-scheduled UEs in the same resource block, and demodulation reference signal (DM-RS) configuration. Besides qualitative analysis from various system impacts, e.g., signaling overhead, scheduling flexibility and channel estimation accuracy, extensive numerical results are provided by both link-level and system-level simulations. In addition, we further propose an adaptive data mapping scheme for transparent MU-MIMO to improve the channel estimation accuracy. Moreover, a novel system-level simulation methodology taking into account dynamic change of channel estimation error is provided in this paper. Finally, based on the investigation results, we propose transparent MU-MIMO with quasi-orthogonal DM-RS configuration in LTE-A. View full abstract»

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    Joint resource management in down-link LTE systems: A non-cooperative game model

    Chungang Yang ; Jiandong Li ; Min Sheng
    Signal Processing, Communications and Computing (ICSPCC), 2011 IEEE International Conference on

    DOI: 10.1109/ICSPCC.2011.6061614
    Publication Year: 2011 , Page(s): 1 - 4
    Cited by:  Papers (1)

    IEEE Conference Publications

    A joint PRB management and power control in LTE self-optimizing networks is proposed using the non-cooperative game with resource consuming pricing into consideration. We derive the closed-form of optimal PRB and power control strategies, based on which we develop the joint PRB and power control algorithms for the down-link LTE. Simulation results verify the performance of the presented scheme with the benchmark schemes. View full abstract»

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    Analysis of PDCCH Performance for M2M Traffic in LTE

    Osti, P. ; Lassila, P. ; Aalto, S. ; Larmo, A. ; Tirronen, T.
    Vehicular Technology, IEEE Transactions on

    Volume: 63 , Issue: 9
    DOI: 10.1109/TVT.2014.2314532
    Publication Year: 2014 , Page(s): 4357 - 4371

    IEEE Journals & Magazines

    As Long-Term Evolution (LTE) is starting to be widely deployed, the volume of machine-to-machine (M2M) traffic is increasing very rapidly. From the M2M traffic point of view, one of the issues to be addressed is the overload of the random access channel. The limitation in the physical downlink control channel (PDCCH) resources may severely constrain the number of devices that an LTE Evolved Node B (eNB) can serve. We develop a Markov model that describes the evolution of the Message 4 queue in the eNB formed by several users performing the random access procedure simultaneously, and then, we study its stability and performance. Our model explicitly takes into account the four initial steps in the random access procedure. By utilizing the model, we are able to determine the stability limit of the system, which defines the maximum throughput and the probability of failure of the random access procedure due to different causes. We observe that the sharing of the PDCCH resources between Messages 2 and 4 with different priorities makes the performance of the whole random access procedure deteriorate very rapidly near the stability limit. However, we can extend the maximum throughput and improve the overall performance by increasing the PDCCH resource size. Furthermore, we estimate the upper limit of the number of devices that can be served by an LTE eNB and determine the minimum PDCCH resource size needed to satisfy a given traffic demand. View full abstract»

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    Capacity evaluation of Carrier Aggregation techniques in LTE-Advanced system

    Shayea, I. ; Ismail, M. ; Nordin, R.
    Computer and Communication Engineering (ICCCE), 2012 International Conference on

    DOI: 10.1109/ICCCE.2012.6271160
    Publication Year: 2012 , Page(s): 99 - 103
    Cited by:  Papers (1)

    IEEE Conference Publications

    In Long Term Evaluation (LTE)-Advanced system, Carrier Aggregation (CA) technique that provide substantial enhancement in data rate transmission for downlink and uplink over wider bandwidth have been proposed. The basic idea of CA technique is to aggregate several smaller contiguous or noncontiguous components, thus concurrent radio resources across multiple carriers are utilized. This paper overview CA technique including data aggregation schemes, bandwidth structure, and CA implementation in LTE-Advanced systems. A simulation model for LTE-Advanced in the downlink has been developed to investigate the impact of CA using up to five Component Carriers (CCs) on the system performance in terms of average throughput and number of active users per cell with respect to non-CA. Simulation show that CA improves the system performance in term of average user throughput within the cell coverage area as CCs increases. Furthermore, CA implementation can enhance the system capacity in term of number of active users in each cell. View full abstract»

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    Optimal MBMS Power Allocation Exploiting MIMO in LTE Networks

    Alexiou, A. ; Bouras, C. ; Kokkinos, V. ; Rekkas, E.
    Vehicular Technology Conference, 2009. VTC Spring 2009. IEEE 69th

    DOI: 10.1109/VETECS.2009.5073746
    Publication Year: 2009 , Page(s): 1 - 5
    Cited by:  Papers (1)  |  Patents (1)

    IEEE Conference Publications

    In the frame of the Long Term Evolution (LTE) of mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance for the LTE proliferation in mobile market. To this end, Multimedia Broadcast/Multicast Service (MBMS) is envisaged to play an instrumental role during LTE standardization process. MBMS was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS) in order to deliver multimedia data from a single source entity to multiple destinations. However, downlink capacity in such networks is limited by base station transmission power. As an aftermath, in MBMS efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. In this paper we propose a power control scheme for efficient selection of MBMS bearers. The proposed mechanism on the one hand manages to economically utilize power resources during MBMS transmissions, while on the other hand exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks. Simulation results indicate that the proposed scheme results to significant power and capacity improvements. View full abstract»

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    Effects of SINR estimation errors on the DL cell throughput of an LTE system in different environments

    Ostermayer, G. ; Neumeier, R. ; Eder, S.
    Communications (MICC), 2013 IEEE Malaysia International Conference on

    DOI: 10.1109/MICC.2013.6805824
    Publication Year: 2013 , Page(s): 196 - 201

    IEEE Conference Publications

    In this paper we analyze the influence of errors in SINR estimation on the system level performance of an LTE system. Additionally we investigate the effect of the selection of the SINR/CQI mapping curve on the cell throughput and error resistance. We focus on downlink scenarios in a macro-cell (57 cells deployed in a hexagonal grid) and a micro-cell environment (Manhattan grid deployment with 72 cells). Up to 20 users are simultaneously active in the observed cell. For that we use a Best CQI scheduling algorithm. Our investigations are done using a simulation environment based on two tools with different modeling accuracy. With that approach the simulation runtime can be kept short enough in order to produce results efficiently. Simulations have shown that the LTE system is very resistant to SINR estimation errors, but it does not always achieve the best cell throughput performance when operating with the parameters for the SINR-to-modulation-and-coding curves recommended in the LTE-standard documents [1]. However, by increasing cell throughput performance, the resistance to SINR estimation errors decreases. View full abstract»

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    The research on the design of the RF front-end for the LTE - Advanced mobile terminals

    Fei Huang ; Jianyi Zhou ; Yingying Chu ; Zhiqiang Yu ; Weicheng Huang
    Microwave and Millimeter Wave Circuits and System Technology (MMWCST), 2013 International Workshop on

    DOI: 10.1109/MMWCST.2013.6814527
    Publication Year: 2013 , Page(s): 372 - 375

    IEEE Conference Publications

    LTE-Advanced technology is required to support 100MHz channel bandwidth and transfer rates in excess of 1Gbps. The 2.6GHz band is one of the core band of LTE-Advanced technology. This paper provide the detailed design of the RF front-end. The receiver uses the traditional double-conversion superheterodyne structure, while transmitter uses a zero-IF structure, able to obtain high receiver sensitivity and channel selectivity and small size. The tests' results show that the overall system performance is generally satisfactory. In the transmitter, the maximum output power is up to 23dBm and IMD3 is better than 45dB, for the 100MHz 16-QAM signal, the modulation accuracy is better than 4.18%; in the receiver, the gain flatness is less than 2.66dB, for the 5MHz 16-QAM modulated signals within the passband, the modulation accuracy is better than 1.34%. The transceiver switch time is less than 1.72μs. View full abstract»

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    Effect of Relaying on Coverage in 3GPP LTE-Advanced

    Beniero, T. ; Redana, S. ; Hamalainen, J. ; Raaf, B.
    Vehicular Technology Conference, 2009. VTC Spring 2009. IEEE 69th

    DOI: 10.1109/VETECS.2009.5073520
    Publication Year: 2009 , Page(s): 1 - 5
    Cited by:  Papers (31)

    IEEE Conference Publications

    Current broadband wireless networks are characterized by large cell sizes. Yet, even in advanced networks that will be built using 3 GPP Long Term Evolution (LTE), also referred to as 3GPP LTE-Advanced, or mobile WiMAX radio interface, users on the cell edge will face relatively low signal-to-interference-plus-noise-ratio (SINR). An attractive solution for this problem is provided by multihop technologies. In this paper we consider the feasibility of Decode and Forward (DF) Relay Nodes (RNs) from 3GPP LTE-Advanced perspective. We propose a novel evaluation methodology that can be used to find a relation of RN transmission power, ratio between number of Base Stations (BSs) and RNs, and performance of the system. Evaluation of DF relays in 3GPP LTE-Advanced framework indicates a good performance gain. View full abstract»

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    Soft interference cancellation receiver for SC-FDMA uplink in LTE

    Shi Cheng ; Narasimhan, R.
    Wireless Communications and Networking Conference (WCNC), 2013 IEEE

    DOI: 10.1109/WCNC.2013.6555095
    Publication Year: 2013 , Page(s): 3318 - 3322

    IEEE Conference Publications

    In this paper, a new soft interference cancellation (SIC) receiver is proposed for the single-carrier frequency-division multiple access (SC-FDMA) multiple-input multiple-output (MIMO) uplink in the Long Term Evolution (LTE) and LTE-Advanced (LTE-A) systems. The receiver works in an iterative fashion between the equalizer and decoder, by using the feedback from the decoder to cancel interfering spatial streams. In addition, the receiver also cancels inter-symbol interference of the desired stream caused by frequency selective fading channel, which reduces the well known “noise enhancement” effect in SC-FDMA. Two types of structures, parallel SIC (P-SIC) and serial SIC (S-SIC) are presented, and an iterative channel estimation method is introduced to further improve the performance of the SIC receiver. Feedback reliability metrics are defined and applied during equalization to avoid catastrophic error propagation. Simulation results demonstrate that with proper reliability metrics, hard slicing on feedback symbol generation can be used to save computational complexity with very small performance loss compared to soft slicing. View full abstract»

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    Power Allocation-Based Adjacent Channel Interference Reduction for Coexisting TD-LTE and LTE-FDD Networks

    Yang Lan ; Harada, A.
    Vehicular Technology Conference (VTC Spring), 2013 IEEE 77th

    DOI: 10.1109/VTCSpring.2013.6692717
    Publication Year: 2013 , Page(s): 1 - 5

    IEEE Conference Publications

    In Long Term Evolution (LTE) networks, two operators might deploy their networks based on frequency division multiplexing (FDD) and time division multiplexing (TDD) in the same geographical area utilizing adjacent frequency bands. In this kind of an environment, the mutual interference, also called adjacent channel interference (ACI), caused by the coexisting adjacent channels of those networks will result in capacity degradation in both systems. In this paper, we investigate the coexistence problem between two macrocells in LTE networks and propose a power allocation-based solution comprising two methods for the base station (BS)-to-BS ACI scenario. Compared to the guard band (GB)-based solution, the proposed methods offer higher spectrum efficiency and even better performance when the GB is equal to or narrower than 10 MHz. View full abstract»

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    Simulation-based performance study of YouTube service in 3G LTE

    Prados-Garzon, J. ; Ameigeiras, P. ; Navarro-Ortiz, J. ; Lopez-Soler, J.M.
    World of Wireless, Mobile and Multimedia Networks (WoWMoM), 2013 IEEE 14th International Symposium and Workshops on a

    DOI: 10.1109/WoWMoM.2013.6583422
    Publication Year: 2013 , Page(s): 1 - 3

    IEEE Conference Publications

    In this paper, we study the performance of the YouTube service over 3G Long Term Evolution (LTE) by means of dynamic network simulations. We consider a typical configuration of an LTE network for TCP traffic and the traffic generation model for YouTube `Flash' videos downloaded onto a personal computer (PC). Furthermore, in order to achieve more reliable results in the simulations, the main configuration parameters are obtained for TCP Cubic congestion control algorithm used by YouTube media servers. The results obtained show that: the number of pauses experimented by users during video download are heavily influenced by the cell load, but the same is not true for pause duration; most of the packet losses occur during initial burst due to the TCP adaptation to the BDP of the link, and, unlike packet losses during throttling phase, these are not depend on radio link quality; and in most cases the user do not use the maximum data rate achievable in the LTE interface. View full abstract»

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    Comparison of Different Virtual MIMO Detection Schemes for 3GPP LTE

    Shengbing Cai ; Zhemin Duan ; Jin Gao
    Wireless Communications, Networking and Mobile Computing, 2009. WiCom '09. 5th International Conference on

    DOI: 10.1109/WICOM.2009.5303835
    Publication Year: 2009 , Page(s): 1 - 5
    Cited by:  Papers (2)

    IEEE Conference Publications

    This paper addresses the issues of MIMO detection schemes for LTE uplink at received port when VMIMO scheme is deployed at transmitter, which is always a trade-off between performance and complexity. More specifically,the authors will focus on the deployment of of virtual MIMO in the UTRA LTE uplink and investigate two different received detection algorithms,namely zero-forcing and minimum mean squared error successive interference cancellation, proposed for V-MIMO detection considering performances and as well as computational complexity.Finally link level simulation results are provided to evaluate algorithms for implementation and feasibility.lt has shown ZF-SIC outperforms somewhat MMSE-SIC in terms of BER under diverse practical scenarios dedicated for LTE systems. View full abstract»

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    Algorithms for Enhanced Inter-Cell Interference Coordination (eICIC) in LTE HetNets

    Deb, S. ; Monogioudis, P. ; Miernik, J. ; Seymour, J.P.
    Networking, IEEE/ACM Transactions on

    Volume: 22 , Issue: 1
    DOI: 10.1109/TNET.2013.2246820
    Publication Year: 2014 , Page(s): 137 - 150
    Cited by:  Papers (4)

    IEEE Journals & Magazines

    The success of LTE heterogeneous networks (HetNets) with macrocells and picocells critically depends on efficient spectrum sharing between high-power macros and low-power picos. Two important challenges in this context are: 1) determining the amount of radio resources that macrocells should offer to picocells, and 2) determining the association rules that decide which user equipments (UEs) should associate with picos. In this paper, we develop a novel algorithm to solve these two coupled problems in a joint manner. Our algorithm has provable guarantee, and furthermore, it accounts for network topology, traffic load, and macro-pico interference map. Our solution is standard compliant and can be implemented using the notion of Almost Blank Subframes (ABS) and Cell Selection Bias (CSB) proposed by LTE standards. We also show extensive evaluations using RF plan from a real network and discuss self-optimized networking (SON)-based enhanced inter-cell interference coordination (eICIC) implementation. View full abstract»

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    On the Evolution of Multi-Cell Scheduling in 3GPP LTE / LTE-A

    Pateromichelakis, E. ; Shariat, M. ; ul Quddus, A. ; Tafazolli, R.
    Communications Surveys & Tutorials, IEEE

    Volume: 15 , Issue: 2
    DOI: 10.1109/SURV.2012.071812.00127
    Publication Year: 2013 , Page(s): 701 - 717
    Cited by:  Papers (12)

    IEEE Journals & Magazines

    This paper provides a holistic overview of multi-cell scheduling strategies in emerging wireless systems. Towards this objective, the evolution of interference management techniques is thoroughly investigated from simple inter-cell interference coordination (ICIC) techniques towards more advanced coordinated multipoint transmissions (CoMP), while comparing and contrasting their common features and differences. Finally CoMP is explored in detail as an advanced and challenging mechanism to fully cooperate between adjacent cells in order to have an efficient resource allocation and inter-cell interference mitigation in multi-cell environments. View full abstract»

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    LTE planning for Soft Frequency Reuse

    Giambene, G. ; Yahiya, T.A.
    Wireless Days (WD), 2013 IFIP

    DOI: 10.1109/WD.2013.6686468
    Publication Year: 2013 , Page(s): 1 - 7

    IEEE Conference Publications

    Future 4G cellular systems will address the need of capacity increase for the support of diverse Internet services. This article deals with cell capacity issues and cell planning for LTE technology. The Soft Frequency Reuse (SFR) scheme is considered here as an interesting approach to efficiently utilize the bandwidth in LTE systems. With SFR, a cell is divided into two parts (the central part and the external part) using different reuse schemes. On the basis of a suitable path loss model, we have been able to characterize the Signal to Interference plus Noise Ratio (SINR) and the probability to use different transmission modes in a cell with SFR. This has allowed us to evaluate the capacity of a cell that can be achieved with SFR. Finally, a cell capacity optimization has been carried out by means of extensive numerical results in order to select both the radius of the cell-center region and the border-to-center power ratio of SFR. View full abstract»

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    Performance of Channel-Aware M2M communications based on LTE network measurements

    Ide, Christoph ; Dusza, Bjoern ; Wietfeld, Christian
    Personal Indoor and Mobile Radio Communications (PIMRC), 2013 IEEE 24th International Symposium on

    DOI: 10.1109/PIMRC.2013.6666400
    Publication Year: 2013 , Page(s): 1614 - 1618

    IEEE Conference Publications

    The interaction between Machine-to-Machine (M2M) Communications, also known as Machine-Type Communications (MTC), and Human-to-Human (H2H) Communications is a recent topic in the context of cellular networks like Long Term Evolution (LTE). In this paper, we evaluate the performance of Channel-Aware MTC (CAT) based on LTE resource allocation measurements of a real LTE deployment. By means of a novel measurement setup, which uses a real-time spectrum analyzer, the LTE resource utilization in terms of occupied Resource Blocks (RBs) of the uplink is quantified for different channel conditions. Furthermore, the resource distribution in time and frequency domain, which is determined by the scheduler, is analyzed in this paper allowing for the calculation of average data rates and the spectral efficiency. The measurement results are used to quantize the potential gain of CAT. It is shown that by means of the scheme, the influence of MTC on other LTE users can be significantly reduced. In addition, the fraction of available RBs can be increased by 47%. View full abstract»

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    Multisite field trial for LTE and advanced concepts

    Irmer, R. ; Mayer, H.-P. ; Weber, A. ; Braun, V. ; Schmidt, M. ; Ohm, M. ; Ahr, N. ; Zoch, A. ; Jandura, C. ; Marsch, P. ; Fettweis, G.
    Communications Magazine, IEEE

    Volume: 47 , Issue: 2
    DOI: 10.1109/MCOM.2009.4785385
    Publication Year: 2009 , Page(s): 92 - 98
    Cited by:  Papers (36)  |  Patents (1)

    IEEE Journals & Magazines

    The 3GPP LTE standard is stable now in its first release (Release 8), and the question is how good its performance is in real-world scenarios. LTE is also a good base for further innovations, but it must be proven that they offer performance advantages for the price of their complexity. This article evaluates the performance of LTE Release 8 as a baseline and advanced concepts currently in discussion such as cooperative MIMO based on system-level simulations, and measurements in the laboratory and a multisite field testbed within the EASY-C project. View full abstract»

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    Scheduling and capacity estimation in LTE

    Osterbo, O.
    Teletraffic Congress (ITC), 2011 23rd International

    Publication Year: 2011 , Page(s): 63 - 70
    Cited by:  Papers (4)

    IEEE Conference Publications

    Due to the variation of radio condition in LTE the obtainable bitrate for active users will vary. The two most important factors for the radio conditions are fading and pathloss. By including both fast fading and shadowing and attenuation due to distance we have developed analytical models to investigate obtainable bitrates for the basic resource unit in LTE. In addition we estimate the total cell throughput/capacity by taking scheduling into account. Particularly, the cell throughput is investigated for three types of scheduling algorithms; Round Robin, Proportional Fair and Max SINR (signal-to-interference-plus-noise ratio) were also fairness among users is part of the analysis. In addition models for cell throughput/capacity for a mixture of Guaranteed Bit Rate (GBR) and Non-GBR greedy users are derived. Numerical examples show that multi-user gain is large for the Max-SINR algorithm, but also the Proportional Fair algorithm gives relative large gain relative to plain Round Robin. The Max-SINR has the weakness that it is highly unfair when it comes to capacity distribution among users. Further, the model visualize that use of GBR with high rates may cause problems in LTE due to the high demand for radio resources for users with low SINR, i.e. at cell edge. Hence, for GBR sources the allowed guaranteed rate should be limited. View full abstract»

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    The effect of a new hybrid decision handover algorithm on QoS in two-tier LTE-A network

    Knapp, A. ; Godor, G.
    Software, Telecommunications and Computer Networks (SoftCOM), 2014 22nd International Conference on

    DOI: 10.1109/SOFTCOM.2014.7039126
    Publication Year: 2014 , Page(s): 331 - 335

    IEEE Conference Publications

    New sophisticated solutions are required in next generation networks to provide appropriate quality of service for users. The introduction of small cells in Long Term Evolution (LTE) raises numerous problems along with undoubted advantages to the engineers and researchers. In this paper a new handover decision algorithm is described for two-tier macrocell-small cell LTE-Advanced (LTE-A) using network map, i.e. positioning service and additional network provided information. The proposed algorithm processes information on the reported RSSI, the speed of users and the actual load of cells extended with a sliding averaging window on RSSI. Simulation results focus on QoS parameters and show that the new decision procedure ensures higher system throughput and lower delay than the legacy, strongest cell algorithm in most scenarios. View full abstract»

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    LTE-advanced downlink throughput evaluation in the 3G and TV white space bands

    Ameen, A.S. ; Mellios, E. ; Doufexi, A. ; Dahnoun, N. ; Nix, A.R.
    Personal Indoor and Mobile Radio Communications (PIMRC), 2013 IEEE 24th International Symposium on

    DOI: 10.1109/PIMRC.2013.6666240
    Publication Year: 2013 , Page(s): 771 - 775
    Cited by:  Papers (1)

    IEEE Conference Publications

    To maintain a high quality of service to the increasing number of smartphone users, additional spectrum is required. The TV white space bands provide a good opportunity to achieve this goal. They can be used as standalone spectrum or aggregated with other licensed bands to increase the total available bandwidth. This paper compares the downlink throughput performance of LTE-Advanced in two different frequency bands. It also addresses the impact of smartphone orientation, with results quoted for three different elevation angles. We consider the higher LTE-Advanced band at 2.6 GHz and the TV white space band at 800 MHz. The radio channel is modelled using a state-of-the-art 3D ray-tracing tool combined with measured 3D radiation patterns for the base station and handset antennas. The throughput performance for a large number of base station and mobile terminal locations is investigated in two different UK cities. We use the computationally efficient received bit information rate algorithm to compute packet error rate as a function of channel structure and SNR. The approach reduces simulation run time by a factor of more than 300. Similar average throughput vs SNR results are observed in both frequency bands. However, higher K-factor and total received power levels are observed when the user equipment is tilted to 45o in elevation. Throughput results show that the efficiency of carrier aggregation between LTE and TVWS bands depends on the cell size and the type of urban environment. View full abstract»

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    Optimized scheduling algorithm for LTE downlink system

    Tran, S.V. ; Eltawil, A.M.
    Wireless Communications and Networking Conference (WCNC), 2012 IEEE

    DOI: 10.1109/WCNC.2012.6214011
    Publication Year: 2012 , Page(s): 1462 - 1466
    Cited by:  Papers (2)

    IEEE Conference Publications

    Orthogonal Frequency Division Multiple Access (OFDMA), Multiple Input Multiple Output (MIMO), and Adaptive Modulation and Coding (AMC) are advanced signal processing techniques introduced in the wireless 3GPP LTE standard. In MIMO-OFDMA system, by taking advantage of the spatial dimension and depending on the time-varying wireless channel condition, the most efficient modulation and coding with spatial multiplexing or spatial diversity is selected to increase system capacity or improve system reliability. Wireless resource is divided into resource blocks (RBs), and the central idea is to effectively allocate these RBs to maximize system capacity and satisfy all active users QoS requirements. Scheduling of the available RBs in an optimized manner is therefore a main thrust in the design of LTE system. In this paper, an optimized scheduling algorithm from a holistic view of the LTE downlink system taking into account the combination of frequency-time packet scheduling (FTPS) with added spatial dimension or MIMO and QoS awareness is developed. Simulation results are presented that confirm the performance improvement of the proposed technique. View full abstract»

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    A low complexity channel estimation approach of LTE downlink system

    Subin Wang ; Chunjing Hu ; Tao Peng ; Wenbo Wang
    Communication Technology (ICCT), 2012 IEEE 14th International Conference on

    DOI: 10.1109/ICCT.2012.6511204
    Publication Year: 2012 , Page(s): 143 - 147

    IEEE Conference Publications

    Channel estimation is critical to receiver performance in the long term evolution (LTE) system. Reference signals are interspersed with data signals among the subcarriers to aid channel estimation. Linear minimum mean square error (LMMSE) channel estimation is an efficient approach to estimate the knowledge of channel with high complexity. This paper proposed a channel estimation approach based on singular value decomposition (SVD) for downlink channel in LTE system. Compared to the conventional algorithm, the proposed approach investigates the channel autocorrelation matrix respectively and substitutes it by small submatrices to reduce the complexity. The simulation result demonstrates that the complexity is significantly reduced with negligible performance degradation, so it could be a candidate of the channel estimation algorithm for downlink channel estimation in LTE system. View full abstract»

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    WiFi leakage detection in LTE downlink for in-device interference avoidance

    Xue Li ; Plumb, B. ; Zhiqiang Wu
    Circuits, Devices & Systems, IET

    Volume: 8 , Issue: 5
    DOI: 10.1049/iet-cds.2013.0449
    Publication Year: 2014 , Page(s): 397 - 405

    IET Journals & Magazines

    To allow users to access networks ubiquitously, more user equipments contain multiple radio transceivers. Because of the proximity of transmit and receive frequencies of in-device wireless technologies, the transmitter (TX) of one in-device wireless technology can interfere with the reception of another technology within the same device, and the spurious emissions of the aggressor TX may result in unacceptable interference at the victim receiver. Hence, it is crucial to detect the in-device interference and adapt strategies to avoid harm. Here, we consider one scenario in 3GPP discussions: the co-existence of Long-Term Evolution (LTE) with WiFi. Different from traditional spectrum sensing which detects signal in the background of Gaussian noise, the WiFi leakage detection in this study aims to detect WiFi leakage in the presence of both LTE signal and noise. Furthermore, most of the WiFi signal features are lost in the WiFi leakage because of the LTE RX filtering which makes the WiFi leakage problem very challenging. By identifying unique features of the WiFi leakage, we investigate this problem thoroughly and propose a suite of detection algorithms, including energy-ratio-based, entropy ratio-based and cyclostationary analysis-based algorithms. Simulations under different scenarios are presented to illustrate the effectiveness and efficiency of the proposed techniques. View full abstract»

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    The MIMO antenna design for a TD-LTE mobile phone

    Wang Wei ; Wei Chongyu ; Wei Weichen
    Antennas & Propagation (ISAP), 2013 Proceedings of the International Symposium on

    Volume: 02
    Publication Year: 2013 , Page(s): 1311 - 1313

    IEEE Conference Publications

    TD-LTE mobile communication systems use MIMO technology. In this paper, a mobile phone MIMO antenna design with two elements having high isolation is presented. The antenna can work in 2300/2500MHz frequency bands. The method of distance isolation is used to reduce the coupling between the two antenna elements. HFSS is used in the simulation analysis and optimization of the antenna. Test results show that antenna return loss, gain and isolation between the two elements meet the TD-LTE phone needs. View full abstract»

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    Spectrum sensing and detection of incumbent-UEs in secondary-LTE based aerial-terrestrial networks for disaster recovery

    Arunthavanathan, S. ; Kandeepan, S. ; Evans, R.J.
    Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), 2013 IEEE 18th International Workshop on

    DOI: 10.1109/CAMAD.2013.6708117
    Publication Year: 2013 , Page(s): 201 - 206
    Cited by:  Papers (5)

    IEEE Conference Publications

    In a disaster recovery scenario, there is a need for the deployment of a supplementary communications infrastructure when the regular communications infrastructure is considered to be damaged and is temporarily unavailable. Hence, we consider such a supplementary network operating as secondary user of the spectrum, which opportunistically utilizes the same spectral band as the incumbent regular network until the incumbent comes alive. When the incumbent network comes alive, it is important to vacate the corresponding spectral bands without interfering with its communications. In our work, we consider both the secondary and incumbent networks as LTE networks where the secondary network has an aerial base station with low altitude platform. In this paper, we propose a method to perform spectrum sensing at the aerial eNodeB for the secondary LTE network in order to detect the incumbent user equipments on ground to avoid interfering with them. A novel approach is presented to perform this task considering the 3GPP-LTE uplink transmission specifications. Moreover, we consider the energy based spectrum sensing for detecting the incumbent users on the ground by the aerial eNodeB, and extensive simulation results are presented in a Rice fading environment for the detection and the false alarm probabilities. View full abstract»

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    LTE-HI: A new solution to future wireless mobile broadband challenges and requirements

    Shanzhi Chen ; YingMin Wang ; Fei Qin ; Zukang Shen ; Shaohui Sun
    Wireless Communications, IEEE

    Volume: 21 , Issue: 3
    DOI: 10.1109/MWC.2014.6845051
    Publication Year: 2014 , Page(s): 70 - 78

    IEEE Journals & Magazines

    Future wireless mobile broadband systems will address the demand of high data rate due to the explosive growth of mobile Internet traffic. Deploying a layer of dense small cells with low transmit power is an effective means to meet the data rate requirement. As one of the prospective solutions to future mobile broadband systems, TDD-based LTE-Hi aims to provide higher performance in hotspots and indoor environments by exploiting wider transmission bandwidth in higher frequency band(s) and being seamlessly integrated with conventional LTE macro-cells. This article outlines the main challenges faced by future wireless mobile broadband and presents the key technical enhancements for LTE-Hi. View full abstract»

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    Efficient measurement procedure for handover in LTE femtocell networks

    Chia-Wei Chang ; Yu-Hsiang Lin ; Rong-Hong Jan ; Chien Chen
    Mobile and Wireless Networking (iCOST), 2012 International Conference on Selected Topics in

    DOI: 10.1109/iCOST.2012.6271278
    Publication Year: 2012 , Page(s): 119 - 123
    Cited by:  Papers (1)

    IEEE Conference Publications

    In LTE (Long Term Evolution) femtocell networks, user equipment (UE) has to measure all the eNBs and Home eNBs (HeNBs) in the Measurement Configuration and find a suitable eNB (or HeNB) to hand over to. However, there are many HeNBs under the coverage of one eNB. In other words, the UE has to measure all the eNBs and HeNBs, no matter whether they are in or out of range. In addition, in many urban areas, the indoor signal strength of LTE networks is fairly good due to the dense deployment of eNBs. As a consequence, the source eNB will not ask the UE entering the coverage of an HeNB to perform the measurement procedure because the source eNB can still provide a desirable signal strength. In this case, the UE will still camp on the eNB, and the HeNB is therefore idle. In this paper, we propose an efficient measurement procedure for handover in LTE femtocell networks to solve the two above-mentioned problems. The simulation results show that the measurement overhead and the average idle time are significantly reduced. View full abstract»

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    The role of MSC Server in LTE based network architecture

    Majačić, D. ; Pećnik, K.
    MIPRO, 2010 Proceedings of the 33rd International Convention

    Publication Year: 2010 , Page(s): 440 - 443

    IEEE Conference Publications

    LTE is new technology for mobile telecommunications that take in consideration all architecture elements from current mobile networks. Every new technology is much better accepted if it offers interoperation with network elements that are currently used. Goal of this paper is to examine position of MSC Server in core networks after introducing of LTE system in already complex mobile networks. Starting point is that current mobile networks with MSC Server are using CS access and ISUP protocol for voice services, while LTE networks are pure PS networks and main protocol is SIP protocol. This paper will analyze requirements for MSC Server for interoperation with LTE and IMS systems. Also possibility of using voice services and SMS in LTE networks and continuity of voice session while changing access network will be analyzed. View full abstract»

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    A study on uplink scheduling techniques in LTE

    Ang Ee Mae ; Wee Kuok Kwee ; Anwar, K.
    Electronics, Information and Communications (ICEIC), 2014 International Conference on

    DOI: 10.1109/ELINFOCOM.2014.6914366
    Publication Year: 2014 , Page(s): 1 - 2

    IEEE Conference Publications

    In the event of the growing demands, Long-Term Evolution (LTE) was introduced to satisfy user's needs. User's demands are for improvement in the throughput as well as the Quality of Service (QoS) in the wireless network. Hence, through this research, tests on several uplink scheduling methods are carried out, and the data produced from the tests are collected and analyzed. Simulation results showed that LTE-compliant round robin approach outperforms the first maximum expansion which has been proposed earlier in transmitting real-time applications over LTE. View full abstract»

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    Enabling LTE/WiFi coexistence by LTE blank subframe allocation

    Almeida, E. ; Cavalcante, A.M. ; Paiva, R.C.D. ; Chaves, F.S. ; Abinader, F.M. ; Vieira, R.D. ; Choudhury, S. ; Tuomaala, E. ; Doppler, K.
    Communications (ICC), 2013 IEEE International Conference on

    DOI: 10.1109/ICC.2013.6655388
    Publication Year: 2013 , Page(s): 5083 - 5088
    Cited by:  Papers (3)

    IEEE Conference Publications

    The recent development of regulatory policies that permit the use of TV bands spectrum on a secondary basis has motivated discussion about coexistence of primary (e.g. TV broadcasts) and secondary users (e.g. WiFi users in TV spectrum). However, much less attention has been given to coexistence of different secondary wireless technologies in the TV white spaces. Lack of coordination between secondary networks may create severe interference situations, resulting in less efficient usage of the spectrum. In this paper, we consider two of the most prominent wireless technologies available today, namely Long Term Evolution (LTE), and WiFi, and address some problems that arise from their coexistence in the same band. We perform exhaustive system simulations and observe that WiFi is hampered much more significantly than LTE in coexistence scenarios. A simple coexistence scheme that reuses the concept of almost blank subframes in LTE is proposed, and it is observed that it can improve the WiFi throughput per user up to 50 times in the studied scenarios. View full abstract»

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    Throughput, Capacity, Handover and Latency Performance in a 3GPP LTE FDD Field Trial

    Wylie-Green, M.P. ; Svensson, T.
    Global Telecommunications Conference (GLOBECOM 2010), 2010 IEEE

    DOI: 10.1109/GLOCOM.2010.5683398
    Publication Year: 2010 , Page(s): 1 - 6
    Cited by:  Papers (4)

    IEEE Conference Publications

    This article presents a summary of 3GPP Long Term Evolution (LTE) radio system performance during the execution of a multi-site field trial. This exhaustive testing campaign, performed over the lower 700 MHz and 2 GHz bands, includes a battery of stationary and mobility throughput cases, multi-user capacity scenarios, handover performance and latency tests, that have been designed to reveal LTE radio performance under a variety of realistic user scenarios. Tests have been performed using a Category 2 LTE UE, which can handle a maximum transport of 50 Mbps in the downlink and 25 Mbps in the uplink. As the results indicate, the system boasts a peak downlink single-user throughput in excess of 49 Mbps and a peak uplink single-user throughput observed of 19 Mbps, which is quite close to the theoretical uplink limit of 21 Mbps. In multi-user scenarios with four active users, in the best case, we have measured a cell throughput of 47 Mbps in the downlink and 20 Mbps in the uplink, which is close to the theoretical best. Finally, as we show, the system achieves a handover success rate of 100% and a best case average user plane latency of 22ms. View full abstract»

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    A survey of trunking communications over LTE: Implementation framework, application requirements, and quality of service

    Hongtao Yu ; Siyue Sun ; Qiyue Yu ; Chenguang He ; Weixiao Meng ; Xuezhi Tan ; Zhongzhao Zhang
    Wireless Communications and Networking Conference (WCNC), 2013 IEEE

    DOI: 10.1109/WCNC.2013.6555293
    Publication Year: 2013 , Page(s): 4439 - 4444

    IEEE Conference Publications

    Trunking communications has been widely applied in dedicated areas for many years, owning to its powerful functionality of scheduling and immediate group communication. Evolution of such services over the cellular mobile network attracts more and more interests due to its wider coverage and cheaper establishment and maintenance cost, especially with the coming era of Long Term Evolution (LTE). In this paper, a survey work is proposed to analyze the application prospects and requirements of the trunking communications over LTE. Taking the push-to-talk over cellular (PoC) as a candidate, the implementation framework is presented. Additionally, the key issues to guarantee quality-of-service (QoS) of the LTE-based PoC service are well analyzed in this paper. View full abstract»

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    Device-to-Device Discovery for Proximity-Based Service in LTE-Advanced System

    Kae Won Choi ; Zhu Han
    Selected Areas in Communications, IEEE Journal on

    Volume: 33 , Issue: 1
    DOI: 10.1109/JSAC.2014.2369591
    Publication Year: 2015 , Page(s): 55 - 66

    IEEE Journals & Magazines

    In this paper, we propose a device-to-device (D2D) discovery scheme as a key enabler for a proximity-based service in the Long-Term Evolution Advanced (LTE-A) system. The proximity-based service includes a variety of services exploiting the location information of user equipment (UE), for example, the mobile social network and the mobile marketing. To realize the proximity-based service in the LTE-A system, it is necessary to design a D2D discovery scheme by which UE can discover another UE in its proximity. We design a D2D discovery scheme based on the random access procedure in the LTE-A system. The proposed random-access-based D2D discovery scheme is advantageous in that 1) the proposed scheme can be readily applied to the current LTE-A system without significant modification; 2) the proposed scheme discovers pairs of UE in a centralized manner, which enables the access or core network to centrally control the formation of D2D communication networks; and 3) the proposed scheme adaptively allocates resource blocks for the D2D discovery to prevent underutilization of radio resources. We analyze the performance of the proposed D2D discovery scheme. A closed-form formula for the performance is derived by means of the stochastic geometry-based approach. We show that the analysis results accurately match the simulation results. View full abstract»

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    Self-configuration of basic LTE radio parameters using Magnetic Field Model

    Premnath, K.N. ; Pradhan, P. ; Darshan, R. ; Schmelz, L.C.
    Wireless Communication Systems (ISWCS), 2012 International Symposium on

    DOI: 10.1109/ISWCS.2012.6328325
    Publication Year: 2012 , Page(s): 36 - 40

    IEEE Conference Publications

    The success of communication service providers (CSPs) relies on efficient operational strategies for managing their networks, including the planning, optimisation and maintenance, in order to meet the desired Quality of Service (QoS), Quality of Experience (QoE) and business goals and requirements. Such business goals and requirements include, amongst others, the reduction of Operational and Capital Expenditure (OPEX and CAPEX). Self Organising Networks (SON) functionalities, including self-configuration, self-optimisation and self-healing, play a crucial role in minimising OPEX [1]. SON has been leveraged by the operator forum Next Generation Mobile Networks (NGMN) [12] and standardised by the 3rd Generation Partnership Project (3GPP) [9][11], in particular for Long Term Evolution (LTE) radio access networks. This paper presents a new solution for the self-configuration of the basic LTE radio parameters Physical Cell ID (PCI) and Physical Random Access Channel (PRACH) using Magnetic Field Model (MFM) techniques, providing a new approach with respect to the existing solutions for PCI allocation [3] in LTE networks. View full abstract»

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    Low complexity downlink channel estimation for LTE systems

    Rana, M.M. ; Jinsang Kim ; Won-Kyung Cho
    Advanced Communication Technology (ICACT), 2010 The 12th International Conference on

    Volume: 2
    Publication Year: 2010 , Page(s): 1198 - 1202
    Cited by:  Papers (1)  |  Patents (1)

    IEEE Conference Publications

    The 3rd generation partnership project (3GPP) long term evolution (LTE) is designed for high speed data rate, higher spectral efficiency, improved services, and lower latency as well as high-capacity voice support. LTE uses orthogonal frequency division multiplexing access (OFDMA) scheme for the downlink transmission and single carrier frequency division multiple access (SCFDMA) in uplink. Main challenges for a terminal implementation are efficient realization of the inner receiver, especially for channel estimation (CE) and equalization. In this paper, a new channel estimator is presented for an OFDMA system under the umbrella of the 3GPP LTE that can avoid the ill-conditioned least square (LS) problem. This channel estimation method uses knowledge of channel properties to estimate the unknown channel transfer function at non-pilot sub-carriers. Therefore, the computational complexity can be reduced significantly. View full abstract»

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    A red-based discard strategy for unacknowledged mode RLC in LTE

    Yi Zheng ; Qiyue Yu ; Weixiao Meng ; Cheng Li
    Global Communications Conference (GLOBECOM), 2013 IEEE

    DOI: 10.1109/GLOCOMW.2013.6855702
    Publication Year: 2013 , Page(s): 4753 - 4758

    IEEE Conference Publications

    In order to satisfy the increasing demands of wireless mobile communications, Long Term Evolution (LTE) has been proposed as an all-IP-based network to bring higher peak data rates and better spectral efficiency. As one of the sub-layers of LTE, Radio Link Control (RLC) layer is likely to congest or overflow due to handover or undesirable channel condition. In this paper, based on Random Early Detection (RED), a discard strategy is proposed for Unacknowledged Mode (UM) RLC to overcome the congestion and buffer overflow problems. Taking LTE systems into account, a simpler improved RED discard strategy is proposed, which is suitable to the delay-sensitive stream that transmitted by a UM RLC entity. This discard strategy can be employed in UE for uplink or evolved NodeBs (eNB) for downlink. The delay and discard performances of the proposed discard strategy are evaluated by both computer simulations and theoretical analysis. According to the simulation results, some suggestions about configuring parameters of the proposed discard strategy are given. In the end, to systematize the strategy and make it more practical, a cross-layer specific proposal is proposed. View full abstract»

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    Design of anelectrically small meander antenna for LTE mobile terminals in the 800 MHz band

    Sharawi, M.S. ; Faouri, Y.S. ; Iqbal, S.S.
    GCC Conference and Exhibition (GCC), 2011 IEEE

    DOI: 10.1109/IEEEGCC.2011.5752508
    Publication Year: 2011 , Page(s): 213 - 216
    Cited by:  Papers (3)

    IEEE Conference Publications

    Fourth generation mobile networks (also called Long Term Evolution - LTE) will make use of multiple-input-multiple-output (MIMO) technology to achieve very high data rates in both the uplink and downlink. MIMO is based on the use of multiple antenna systems within the mobile terminal as well as the base station. The small size of the mobile terminal poses series integration and antenna miniaturization challenges. In this work, we propose an electrically small antenna (ESA) that is based on the meander antenna structure that operates in the 800 MHz band of LTE and 3G cellular standards. The antenna has a measured center frequency of 897 MHz, bandwidth of 185 MHz and total size of 23.5 × 43 mm2. Both simulation and experiment results are presented. A study on the effect of the various antenna parameters that will aid the designer fine tune his structure is also discussed. View full abstract»

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    Simulation and research of TD-LTE power control algorithm

    Chen Yan Yu
    Computer Science & Education (ICCSE), 2012 7th International Conference on

    DOI: 10.1109/ICCSE.2012.6295206
    Publication Year: 2012 , Page(s): 868 - 871

    IEEE Conference Publications

    Uplink power control is a key radio resource management function. It is typically used to maximize the power of the desired received signals while limiting the generated interference. This paper presents the 3GPP long Term Evolution (LTE) power control mechanism, and compares its performance to two reference mechanisms. TD-LTE communications systems are interference limitation systems, The use of power control technology demonstrate the superiority of TD-LTE. Power control is the key technology Resource Allocation Management and interference management, The effective Power Control algorithm reduce the mutual interference of UE, In the case of satisfying the quality of communication of each user, Minimize the emission power, So as to reduce interfere, increase the capacity of system, prolong the standby time of mobilephone. View full abstract»

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    On performance of MIMO-OFDM based LTE systems

    Ajey, S. ; Srivalli, B. ; Rangaraj, G.V.
    Wireless Communication and Sensor Computing, 2010. ICWCSC 2010. International Conference on

    DOI: 10.1109/ICWCSC.2010.5415899
    Publication Year: 2010 , Page(s): 1 - 5
    Cited by:  Papers (2)

    IEEE Conference Publications

    4G wireless systems predominately employ multiple input multiple output (MIMO) with an orthogonal frequency division multiplexing (OFDM) system. Like other 4G systems long term evolution (LTE) also employs MIMO-OFDM physical layer. MIMO helps in increasing the throughput whereas OFDM converts a frequency selective fading channel to multiple flat fading sub-channels facilitating easy equalization. It is proposed that LTE system should mandatorily support 2×2 MIMO setup. Our paper focuses on the performance of such a LTE system with two transmit antennas and two receive antennas in a frequency selective fading environment. View full abstract»

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    Performance of Uplink Carrier Aggregation in LTE-Advanced Systems

    Hua Wang ; Rosa, C. ; Pedersen, K.
    Vehicular Technology Conference Fall (VTC 2010-Fall), 2010 IEEE 72nd

    DOI: 10.1109/VETECF.2010.5594543
    Publication Year: 2010 , Page(s): 1 - 5
    Cited by:  Papers (8)  |  Patents (1)

    IEEE Conference Publications

    Carrier aggregation (CA) has been proposed to aggregate two or more component carriers (CCs) to support a much wider transmission bandwidth for LTE-Advanced systems. With carrier aggregation, it is possible to schedule a user equipment (UE) on multiple component carriers simultaneously. In this paper, we evaluate the performance of uplink CA in LTE-Advanced systems with different CC allocation schemes. We first present the radio resource management (RRM) framework of multi-component carrier LTE-Advanced systems, with special attention on CC selection, adaptive transmission bandwidth, and uplink power control. Simulation results show that with CA and advanced CC selection algorithm, the cell edge user throughput of LTE-Advanced UEs maintains the same as Rel'8 UEs, but substantial performance gains can be achieved in terms of average and cell center user throughput, especially in low load traffic conditions. View full abstract»

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    Joint scheduling for MU-CoMP in uplink LTE-advanced systems

    Yang Liu ; Peng Chen
    Communication Technology (ICCT), 2012 IEEE 14th International Conference on

    DOI: 10.1109/ICCT.2012.6511217
    Publication Year: 2012 , Page(s): 214 - 218

    IEEE Conference Publications

    It has been observed that on the uplink, coordinated multiple-point transmission (CoMP) can obtain significant performance improvements in interference rejection, which has been one of the key techniques in the Long Term Evaluation-Advanced (LTE-A) systems. Meanwhile, multi user-multiple input multiple output (MU-MIMO) can obviously enhance the system spectral efficiency by allocating the same time-frequency resource to multiple users. To obtain high network transmission quality, MU-CoMP will become the promising solution for LTE-A systems, in which the scheduling scheme is the key effect factor. In this paper, a joint scheduling scheme is proposed for optimally employing CoMP and MU-MIMO in the LTE-A systems based on two network topologies. To evaluate the effectiveness of the scheme, the performance of single user (SU)/MU adaptive CoMP using the proposed scheme is simulated and analyzed compared with SU-CoMP, and the simulation results show SU/MU-CoMP can achieve significant gain in cell average spectral efficiency. View full abstract»

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    Multiuser MIMO Scheduling for LTE-A Downlink Cellular Networks

    Jiancun Fan ; Li, G.Y. ; Xiaolong Zhu
    Vehicular Technology Conference (VTC Spring), 2014 IEEE 79th

    DOI: 10.1109/VTCSpring.2014.7022997
    Publication Year: 2014 , Page(s): 1 - 5

    IEEE Conference Publications

    In this paper, we investigate multiuser MIMO scheduling in LTE downlink cellular networks. We formulate the downlink LTE-A MIMO scheduling as a weighted sum rate maximization problem by allocating the RBs to users or user pairs subject to some constraints in LTE-A. We develop a low-complexity MU-MIMO scheduling and resource allocation algorithm and propose an adaptive switching approach between SU-MIMO and MU-MIMO to improve network performance. System-level simulation results demonstrate significantly performance improvement of the proposed MU-MIMO scheduling algorithm and the adaptive switching algorithm. View full abstract»

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    Improved Pilot-Aided channel estimation in LTE uplink

    Hu Su-juan ; Xie Jun ; Yang Feng
    Computational Problem-Solving (ICCP), 2011 International Conference on

    DOI: 10.1109/ICCPS.2011.6089776
    Publication Year: 2011 , Page(s): 64 - 67
    Cited by:  Papers (1)

    IEEE Conference Publications

    Channel Estimation (CE) is one of the key technologies in mobile communication system and also important in Sounding Reference Signal (SRS) that is used to detected channel quality information in LTE uplink. According to the latest LTE specification, the pilot aided CE algorithms for LTE uplink are researched in this paper. To improve the performance and decrease the complexity of traditional channel estimation methods, here we propose a novel Pilot-Aided channel estimation algorithm - Conjugate Cancel (CC) channel estimation, after LS, MMSE and SRS are introduced. The goal of the method is to reduce the computational complexity and restrain the interference of noise. Stimulation shows that the improved method is prior to the traditional algorithms respectively while achieving the purpose of Channel Estimation. View full abstract»

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    Carrier aggregation framework in 3GPP LTE-advanced [WiMAX/LTE Update]

    Iwamura, M. ; Etemad, K. ; Mo-Han Fong ; Nory, R. ; Love, R.
    Communications Magazine, IEEE

    Volume: 48 , Issue: 8
    DOI: 10.1109/MCOM.2010.5534588
    Publication Year: 2010 , Page(s): 60 - 67
    Cited by:  Papers (49)  |  Patents (5)

    IEEE Journals & Magazines

    Carrier aggregation is one of the most distinct features of 4G systems including LTEAdvanced, which is being standardized in 3GPP as part of LTE Release 10. This feature allows scalable expansion of effective bandwidth delivered to a user terminal through concurrent utilization of radio resources across multiple carriers. These carriers may be of different bandwidths, and may be in the same or different bands to provide maximum flexibility in utilizing the scarce radio spectrum available to operators. Support for this feature requires enhancement to the LTE Release 8/9 PHY, MAC, and RRC layers while ensuring that LTE Release 10 maintains backward compatibility to LTE Release 8/9. This article provides an overview of carrier aggregation use cases and the framework, and their impact on LTE Release 8/9 protocol layers. View full abstract»

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    Position Assisted Coordinate HARQ in LTE Systems for High Speed Railway

    Wantuan Luo ; Xuming Fang ; Shasha Li ; Yingying Xia
    Vehicular Technology Conference (VTC Spring), 2013 IEEE 77th

    DOI: 10.1109/VTCSpring.2013.6692716
    Publication Year: 2013 , Page(s): 1 - 5

    IEEE Conference Publications

    Voice over IP (VoIP) in LTE-R (LTE for Railway) will replace the circuit-switched (CS) voice service of the GSMR (GSM for Railway). However, it will face new problems in high speed railway scenario. In overlapping areas, the handover signaling (i.e. handover measurement and decision) is of higher priority than Hybrid Automatic Repeat reQuest (HARQ) retransmission so that the HARQ retransmission will be canceled when conflicts happen. If an user equipment (UE) is handed over to the target eNodeB (eNB), the HARQ retransmission or ACK/NACK of source eNB will not be received by the UE as normal, and the UE will wait for the potential retransmission and ACK/NACK. These particular problems will increase the VoIP packet error rate (PER) significantly. In order to solve these problems, a position assisted coordinate HARQ scheme in LTE system for high speed railway is proposed. With the help of trains position, the source eNB and target eNB share packets through coordination. If the handover is triggered, the UE will stop sending ACK/NACK. When the handover is completed, the UE sends the ACK of the last continuous packet to ensure lossless handover. Simulation results show that our proposal can reduce the VoIP PER in high speed railway scenario, and improve the system reliability, as well as VoIP capacity. View full abstract»

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    UMTS LTE downlink cell size calculation

    Afric, W. ; Pilinsky, S.Z.
    ELMAR, 2012 Proceedings

    Publication Year: 2012 , Page(s): 105 - 108

    IEEE Conference Publications

    This paper deals with cell size calculations for UMTS LTE downlink. As LTE uses adaptable modulation technique, the possibility to use various modulation techniques in cells with different size was analyzed. At the basis of Okomura-Hata propagation model, the equation for maximal cell radius was calculated taking into account the height and gain of both base station and mobile station antenna, transmitter power and losses and receiver sensitivity and losses. Various simulations were performed to give insight into signal propagation in European urban and suburban area. At the basis of simulations it is shown for these areas that UMTS cell structure and size can be used also for LTE cells which will be covered with 64QAM modulation. View full abstract»

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    Admission control strategies and QoS evaluation based on mobility in LTE

    Ben Rejeb, S. ; Nasser, N. ; Tabbane, S.
    Global Communications Conference (GLOBECOM), 2013 IEEE

    DOI: 10.1109/GLOCOMW.2013.6855724
    Publication Year: 2013 , Page(s): 4883 - 4888

    IEEE Conference Publications

    Mobile communication systems have evolved considerably in recent years encouraging the deployment of multiple systems or multi-cellular technology. Quality of service (QoS) offered to mobile users improves from one system to another for example 4G systems, offer better QoS than that offered by 3G and 3.5G systems. In addition, 4G systems such as LTE (Long Term Evolution) can expand cellular coverage and provide higher throughput. New technologies enhance accessibility to the Internet. Migration services from Internet to mobile networks become an important research topic for telecommunications sector. This paper calculates and evaluates system performance by developing a new LTE mechanism for allocating resources in the downlink based on call admission control (CAC) taking into account mobility within and between cellular users. This mechanism uses adaptive modulation and coding (AMC) that divided the geographical area into several concentric regions. With this mechanism each call accepted by the system maintains its initial throughput regardless of the position of the user in the cell. View full abstract»

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    Coordinated LTE uplink radio interface scheduling

    Toseef, U. ; Weerawardane, T. ; Golderer, R. ; Hauth, S. ; Timm-Giel, A. ; Gorgt, C.
    Wireless and Mobile Networking Conference (WMNC), 2013 6th Joint IFIP

    DOI: 10.1109/WMNC.2013.6549002
    Publication Year: 2013 , Page(s): 1 - 8

    IEEE Conference Publications

    Long Term Evolution (LTE) promises substantially higher radio interface throughput compared to 3G access technologies. Sometimes, the bandwidth demands of a time varying LTE user traffic cannot be fulfilled by the existing transport network either due to the limited capacity or because of the inaccuracies involved in the transport link bandwidth dimensioning. This often results in a congestion situation in the transport network. In this study a novel congestion control scheme is introduced for the LTE uplink which works based on the coordination between the limited transport network capacity and the time varying radio interface capacity. The proposed mechanism operates at the eNB where the two network interfaces can be monitored in order to efficiently minimize the congestion situations. The coordination based congestion control algorithm is implemented in an LTE network simulator and its performance is studied for various system load configurations. The simulation results confirm that the proposed algorithm effectively mitigates the congestion and helps achieve an improved uplink application performance. Furthermore, a significant application performance gain is also observed for the downlink applications when the congestion in the uplink is controlled. View full abstract»

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    LTE Downlink Inter-Cell Interference Assessment in an Existing GSM Metropolitan Deployment

    Simonsson, A. ; Hagerman, B. ; Chistoffersson, J. ; Klockar, L. ; Koutsimanis, C. ; Cosimini, P.
    Vehicular Technology Conference Fall (VTC 2010-Fall), 2010 IEEE 72nd

    DOI: 10.1109/VETECF.2010.5594554
    Publication Year: 2010 , Page(s): 1 - 5
    Cited by:  Papers (5)

    IEEE Conference Publications

    In a loaded 1-reuse cellular network as e.g. 3GPP Long Term Evolution (LTE) the inter-cell interference limits the user bitrate for link adaptive packet data access. The cell isolation together with the link performance defines the spectrum efficiency and the achievable gain of higher order modulation or other link improving features. In this paper the cell isolation is measured as geometry factor in a dense city network. The measurements are performed on commercial GSM live traffic capturing the real spatial distribution including indoor usage. The cell plan of the studied metropolitan network is found to be very good and well optimised with the potential to support high user bitrates and high capacity for future LTE high speed radio accesses. The measured geometry factor distribution is superior to those that have been used for capacity evaluations in 3GPP indicating good performance of a possible LTE in existing deployments. A very good match between the live traffic measurements and simulations is found when introducing a tilted 3D antenna model into the cellular radio network simulation environment. Further, the tilted 3D antenna model results in a more realistic amount of interfering cells experienced at simulation estimations of spectrum efficiency. View full abstract»

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    Linearity vs. power consumption of CMOS LNAs in LTE systems

    Szczepkowski, G. ; Farrell, R.
    Signals and Systems Conference (ISSC 2013), 24th IET Irish

    DOI: 10.1049/ic.2013.0044
    Publication Year: 2013 , Page(s): 1 - 8

    IET Conference Publications

    This paper presents a study of linearity in wideband CMOS low noise amplifiers (LNA) and its relationship to power consumption in context of Long Term Evolution (LTE) system. Using proposed figure of merit to compare 35 state-of-the-art LNA circuits published in recent years, the paper shows a proportional but relatively weak dependence between amplifier performance (that is combined linearity, noise figure and gain) with power consumption. As a result, the predicted increase of LNA performance, necessary to satisfy stringent linearity specifications of LTE standard, may require a significant increase in power, a critical budget planning aspect for both handheld devices and base stations operating in small cells. View full abstract»

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    A LTE basic system level simulator on capacity

    Paz Arteaga, C.S. ; Martinez Gomez, E.J. ; Quintero Florez, V.M. ; Hernandez, C.M.
    Communications and Computing (COLCOM), 2014 IEEE Colombian Conference on

    DOI: 10.1109/ColComCon.2014.6860423
    Publication Year: 2014 , Page(s): 1 - 6

    IEEE Conference Publications

    This paper describes the overview of the basic system level simulator for calculation of LTE network capacity, its development, implementation, testing and two simulation scenarios, varying the cell size and number of user equipment by sector to evaluate the performance in capacity (SINR and throughput) in a specific LTE network. View full abstract»

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    Channel estimation for LTE downlink in High Altitude Platforms (HAPs) systems

    Aziz, M.R.K. ; Iskandar
    Information and Communication Technology (ICoICT), 2013 International Conference of

    DOI: 10.1109/ICoICT.2013.6574570
    Publication Year: 2013 , Page(s): 182 - 186

    IEEE Conference Publications

    We describe in this paper, channel estimation performance evaluation of Long Term Evolution (LTE) downlink that uses Orthogonal Frequency Division Multiplexing (OFDM) technique, which employs High Altitude Platforms (HAPs) as radio communication channel. HAPs have advantages due to unique altitude position between terrestrial and satellite systems and hence promising as alternative candidate for radio communication channel in the future. LTE is predecessor of LTE Advanced that has been selected as Fourth Generation (4G) of mobile communication systems. Channel estimation is the vital part of receiver if the system uses coherent and multi-level demodulation. Therefore, we choose two estimation methods, Least Square (LS) and Linear Minimum Mean Square Error (LMMSE), to evaluate the performance in term of Mean Square Error (MSE) and Bit Error Rate (BER) versus Signal Noise to Ratio (SNR). The evaluations are performed in different elevation angles from HAPs to user in the ground, velocities of user, and modulation orders. The performance evaluation results of MSE and BER for LMMSE are better than LS, which lower elevation angle has lower performance. Furthermore, higher velocity make increases the performance gap between elevation angles. Finally, higher modulation order also produces lower performance. View full abstract»

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    Buffering-aided resource allocation for Type I relay in LTE-Advanced cellular networks

    Long Wang ; Qinghe Du ; Pinyi Ren ; Li Sun ; Yichen Wang
    Global Communications Conference (GLOBECOM), 2014 IEEE

    DOI: 10.1109/GLOCOM.2014.7037514
    Publication Year: 2014 , Page(s): 4484 - 4489

    IEEE Conference Publications

    3GPP LTE-Advanced (LTE-A) cellular networks support relay transmissions to improve the cell-edge users throughput as well as the system capacity, so that mobile communications services including multimedia transmissions, data download, real-time online gaming, etc., can be served with better quality-of-services (QoS). In LTE-A networks, Type I relay is widely used, where the relay station (RS) and evolved Node B (eNB) independently schedule and allocate resource for their served user equipments (UE). Existing research often assumes that the backhaul link (connecting eNB and relay) and the access link (connecting relay and UE) employ the same transmission rate, in order to avoid traffic congestions at the RS without queuing buffer. However, this makes the total relay throughput subject to the worse channel quality between the backhaul link and access link, thus severely degrading the system capacity as the wireless channels vary with time. To overcome this problem, this paper enables buffering function at RSs and proposes a buffering-aided three-step resource allocation scheme, which can efficiently make use of the time-varying channel qualities for data delivery. Furthermore, optimizations for the long-term fairness and overall network throughput are jointly designed. Also conducted is a set of system-level simulations to evaluate the performances of the proposed scheme. Simulation results show that the proposed scheme can not only improve the average network throughput compared with existing baseline schemes, but also achieve better long-term fairness over RS-served UEs and eNB-served UEs. View full abstract»

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