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    Selfish attacks and detection in cognitive radio Ad-Hoc networks

    Minho Jo ; Longzhe Han ; Dohoon Kim ; In, H.P.
    Network, IEEE

    Volume: 27 , Issue: 3
    DOI: 10.1109/MNET.2013.6523808
    Publication Year: 2013 , Page(s): 46 - 50

    IEEE Journals & Magazines

    Cognitive radio is an opportunistic communication technology designed to help unlicensed users utilize the maximum available licensed bandwidth. Cognitive radio has recently attracted a lot of research interest. However, little research has been done regarding security in cognitive radio, while much more research has been done on spectrum sensing and allocation problems. A selfish cognitive radio node can occupy all or part of the resources of multiple channels, prohibiting other cognitive radio nodes from accessing these resources. Selfish cognitive radio attacks are a serious security problem because they significantly degrade the performance of a cognitive radio network. In this article we identify a new selfish attack type in cognitive radio ad-hoc networks and propose an easy and efficient selfish cognitive radio attack detection technique, called COOPON, with multichannel resources by cooperative neighboring cognitive radio nodes. View full abstract»

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    Cognitive-radio and antenna functionalities: A tutorial [Wireless Corner]

    Tawk, Y. ; Costantine, J. ; Christodoulou, C.G.
    Antennas and Propagation Magazine, IEEE

    Volume: 56 , Issue: 1
    DOI: 10.1109/MAP.2014.6821791
    Publication Year: 2014 , Page(s): 231 - 243

    IEEE Journals & Magazines

    This paper discusses the fundamental principles of a cognitive-radio RF system. The key points required to achieve a true cognitive-radio device are outlined. The operation of a cognitive-radio system is mainly divided into two tasks. In the first task, a cognitive-radio device searches and identifies any part of the spectrum that is not occupied. The second task consists of achieving an optimal mode of communication by allocating the appropriate channels to be used. In this paper, the RF requirements required to operate a cognitive-radio device are detailed. Such a device can adopt one of two scenarios of a cognitive-radio system: the “interweave” or “underlay” mode of operation. For both scenarios, a cognitive cycle is followed. This cycle consists of the following four steps: (1) observe, (2) decide, (3) act, and (4) learn. A cognitive-radio engine is responsible for managing and integrating these four functions together into a single cognitive-radio device. In this tutorial, the realization of the four functions of a cognitive-radio cycle are detailed for both types of cognitive radio, and various RF front-end examples are presented and discussed. View full abstract»

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    ACRA: An Autonomic and Expandable Architecture for Cognitive Radio Nodes

    Shixian Wang ; Lunguo Xie ; Hengzhu Liu ; Botao Zhang ; Heng Zhao
    Wireless Communications and Signal Processing (WCSP), 2010 International Conference on

    DOI: 10.1109/WCSP.2010.5633818
    Publication Year: 2010 , Page(s): 1 - 5

    IEEE Conference Publications

    Cognitive radio has been a research hotspot because of its promise to improve the utilization of the assigned but unused radio spectrum. The complexity of current networks has been a main drawback of network development, and so will the problem of cognitive radio networks. To solve the complexity problem, autonomic computing has been proposed to enable the network self-management. This paper puts emphasis on the autonomic cognitive radio nodes architecture for the purpose of establishing a cognitive radio network with autonomic computing property from bottom up. We model the cognitive cycle using autonomic computing principles and introduce an autonomic cognitive radio conceptual model. And then, an autonomic cognitive radio nodes architecture (ACRA) based on the proposed conceptual model and a realization method are proposed. ACRA can realize the cognitive radio function with autonomic computing property, which makes the collaboration and management in a network formed by this kind of node easier. View full abstract»

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    Cognitive Radio and Networking Research at Virginia Tech

    MacKenzie, A.B. ; Reed, J.H. ; Athanas, P. ; Bostian, C.W. ; Buehrer, R.Michael ; DaSilva, L.A. ; Ellingson, S.W. ; Hou, Y.T. ; Hsiao, M. ; Jung-Min Park ; Patterson, C. ; Raman, S. ; da Silva, C.
    Proceedings of the IEEE

    Volume: 97 , Issue: 4
    DOI: 10.1109/JPROC.2009.2013022
    Publication Year: 2009 , Page(s): 660 - 688
    Cited by:  Papers (25)

    IEEE Journals & Magazines

    More than a dozen Wireless @ Virginia Tech faculty are working to address the broad research agenda of cognitive radio and cognitive networks. Our core research team spans the protocol stack from radio and reconfigurable hardware to communications theory to the networking layer. Our work includes new analysis methods and the development of new software architectures and applications, in addition to work on the core concepts and architectures underlying cognitive radios and cognitive networks. This paper describes these contributions and points towards critical future work that remains to fulfill the promise of cognitive radio. We briefly describe the history of work on cognitive radios and networks at Virginia Tech and then discuss our contributions to the core cognitive processing underlying these systems, focusing on our cognitive engine. We also describe developments that support the cognitive engine and advances in radio technology that provide the flexibility desired in a cognitive radio node. We consider securing and verifying cognitive systems and examine the challenges of expanding the cognitive paradigm up the protocol stack to optimize end-to-end network performance. Lastly, we consider the analysis of cognitive systems using game theory and the application of cognitive techniques to problems in dynamic spectrum sharing and control of multiple-input multiple-output radios. View full abstract»

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    Software Defined Radio Implementation of SMSE Based Overlay Cognitive Radio

    Ruolin Zhou ; Xue Li ; Chakravarthy, V. ; Bullmaster, C. ; Bin Wang ; Cooper, R. ; Zhiqiang Wu
    New Frontiers in Dynamic Spectrum, 2010 IEEE Symposium on

    DOI: 10.1109/DYSPAN.2010.5457920
    Publication Year: 2010 , Page(s): 1 - 2
    Cited by:  Papers (4)

    IEEE Conference Publications

    In this paper, we use a software defined radio to implement the cognitive centric overlay waveform and demonstrate an adaptive interference avoidance cognitive radio. Specifically, we employ the SMSE framework to generate multi-carrier transmission waveforms over non-contiguous frequency bands for the cognitive radio implementation. Combined with a spectrum sensing engine, the cognitive radio detects the availability of each and every subcarrier in the operational bandwidth. By turning off those subcarriers occupied by the primary users, the cognitive radio implements a non-contiguous SMSE transmission. There are a few unique features of our cognitive radio implementation: (1) we have demonstrated real-time seamless video transmission without interference to primary users and from primary users; (2) our cognitive radio is capable of taking advantage of multiple spectrum holes and operating over multiple non-contiguous spectrum bands; (3) the cognitive radio dynamically adjusts which subcarriers to turn off according to the primary users' transmission; (4) the cognitive radio can also easily adjust other parameters such as the total number of subcarriers, center frequency, bandwidth of each subcarrier, and so on, making it a very flexible and robust cognitive radio node. View full abstract»

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    Notice of Violation of IEEE Publication Principles
    Sensor networks for cognitive radio: Theory and system design

    Reddy, A.V. ; Krishna, E.R. ; Reddy, P.M.
    Electronics Computer Technology (ICECT), 2011 3rd International Conference on

    Volume: 3
    DOI: 10.1109/ICECTECH.2011.5941743
    Publication Year: 2011 , Page(s): 229 - 233
    Cited by:  Papers (1)

    IEEE Conference Publications

    Notice of Violation of IEEE Publication Principles

    "Sensor Networks for Cognitive Radio: Theory and System Design"
    by A.Venkata Reddy, E.Rama Krishna, P.Mahipal Reddy
    in the 2011 3rd International Conference on Electronics Computer Technology (ICECT), Vol. 3, 2011, 229 – 233

    After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles.

    This paper contains significant portions of original text from the paper cited below. The original text was copied with insufficient attribution (including appropriate references to the original author(s) and/or paper title) and without permission.

    Due to the nature of this violation, reasonable effort should be made to remove all past references to this paper, and future references should be made to the following article:

    "Sensor Networks for Cognitive Radio: Theory and System Design"
    by Bertrand Mercier, Viktoria Fodor, Ragnar Thobaben, Mikael Skoglund, Visa Koivunen, Saska Lindfors, Jussi Ryynanen, Erik G. Larsson, Chiara Petriolo, Giancarlo Bongiovanni, Ole Grondalen, Kimmo Kansanen, Geir E. Oien, Torbjorn Ekman, Aawatif M. Hayar, Raymond Knopp, Baltasar Beferull Lozano
    in the ICT MobileSummit 2008

    The increasing demand for wireless communication introduces efficient spectrum utilization. To achieve this, cognitive radio has emerged as the key technology, which enables opportunistic access to the spectrum. Towards dynamic spectrum allocation and cognitive radio, this paper proposes a new approach and innovative techniques to support the coexistence of licensed and unlicensed wireless users in a same area. The proposed concept, called Sensor Network aided Cognitive Radio, consists of a wireless sensor network able to assist the cognitive network by providing information on the current spectrum occupancy. This concept, that will addres- various operational scenarios in the future networks, involves a set of advanced wireless communications techniques like spectrum sensing, interference management, cognitive radio reconfiguration management, cooperative communications, end-to-end protocol design and cross-layer optimization. All these enabling techniques together will form a compound system able to improve the spectrum use in a significant way. The main target scenario we consider is the use of nomadic cognitive radios in urban and suburban areas. Our objective is to develop a proof-of-concept - scheduled in 2010 - of the Sensor Network aided Cognitive Radio technology by implementing such techniques and integrating them on a hardware radio platform, which will allow us to assess the efficiency of the technology in a realistic environment. View full abstract»

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    Characterizing reliability in cognitive radio networks

    Pal, R. ; Idris, D. ; Pasari, K. ; Prasad, N.
    Applied Sciences on Biomedical and Communication Technologies, 2008. ISABEL '08. First International Symposium on

    DOI: 10.1109/ISABEL.2008.4712632
    Publication Year: 2008 , Page(s): 1 - 6
    Cited by:  Papers (5)

    IEEE Conference Publications

    Future wireless communications will require an increasing opportunistic use of the licensed radio frequency spectrum. The cognitive radio (CR) paradigm provides a suitable framework for this purpose. However, the phenomena of channel fading and primary cum secondary interference in cognitive radio networks does not guarantee application demands to be achieved continuously over time. In this paper, we consider the problem of analytically evaluating the reliability of a general multi-hop, multi-channel, multi-radio, multi-rate cognitive radio network, serving a given multi-application demand vector. We define reliability as the probability that a given demand vector is achieved. Each element in the vector is the desired flow rate of an application. We give a detailed simulation study to support our theory, and analyze the effect of the number of channels, radios, and simultaneous flows on the reliability of a CR network. Our quantitative measure of reliability is indicative of the effectiveness of a CR network, and will help network engineers to tune the network for better performance. View full abstract»

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    An autonomic communication based conceptual and architecture model for cognitive radio nodes

    Shixian Wang ; Heng Zhao ; Botao Zhang ; Hengzhu Liu ; Lunguo Xie
    Wireless, Mobile and Multimedia Networks (ICWMNN 2010), IET 3rd International Conference on

    DOI: 10.1049/cp.2010.0651
    Publication Year: 2010 , Page(s): 200 - 204
    Cited by:  Papers (1)

    IET Conference Publications

    Cognitive radio has been a research hotspot because of its promise to improve the utilization of the assigned but unused radio spectrum. To accomplish this task, cognitive radio network should configure itself to adapt to its communication context. Autonomic computing and communication have been proposed to enable the computing and communication network self-management. Based on the similarity between cognitive radio and autonomic communication, the cognitive cycle is modeled by autonomic computing principles. Then, cognitive radio conceptual and architecture model with autonomic property are proposed. Cognitive radio nodes realized by the proposed models are easy to form an autonomic cognitive radio network, which can be looked as an autonomic communication environment. The autonomic cognitive radio node is expressed by autonomic communication element (ACE) architecture and a realization method is given based on the open-source ACE toolkit, which establishes a simulation environment for cognitive radio research. View full abstract»

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    Software Defined Radio Implementation of SMSE Based Overlay Cognitive Radio in High Mobility Environment

    Ruolin Zhou ; Xue Li ; Chakarvarthy, V. ; Zhiqiang Wu
    Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE

    DOI: 10.1109/GLOCOM.2011.6134385
    Publication Year: 2011 , Page(s): 1 - 5
    Cited by:  Papers (1)

    IEEE Conference Publications

    A spectrally modulated spectrally encoded (SMSE) based overlay cognitive radio has been implemented and demonstrated in [1] via GNU software define radio (SDR). However, like most of the current cognitive radio implementations and demonstrations, this work does not consider the mobility between cognitive radio nodes. In a high mobility environment, the frequency offset introduced by Doppler shift leads to loss of the orthogonality among subcarriers. As a direct result, severe inter-carrier interference (ICI) and performance degradation is observed. In our previous work, we have proposed a new ICI cancellation method (namely Total ICI Cancellation) for OFDM [2] and MC-CDMA [3] mobile communication systems, which eliminates the ICI without lowering the transmission rate nor reducing the bandwidth efficiency. In this paper, we apply the total ICI cancellation algorithm onto the SMSE base overlay cognitive radio to demonstrate a high performance cognitive radio in high mobility environment. Specifically, we demonstrate an SMSE based overlay cognitive radio that is capable of detecting primary users in real time and adaptively adjusting its transmission parameters to avoid interference to (and from) primary users. When the primary user transmission changes, the cognitive radio dynamically adjusts its transmission accordingly. Additionally, this cognitive radio maintains seamless real time video transmission between the cognitive radio pair even when large frequency offset is introduced by mobility between CR transmitter and receiver. View full abstract»

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    Predicting Radio Resource Availability in Cognitive Radio - an Experimental Examination

    Kaneko, S. ; Nomoto, S. ; Ueda, T. ; Nomura, S. ; Takeuchi, K.
    Cognitive Radio Oriented Wireless Networks and Communications, 2008. CrownCom 2008. 3rd International Conference on

    DOI: 10.1109/CROWNCOM.2008.4562504
    Publication Year: 2008 , Page(s): 1 - 6
    Cited by:  Papers (6)

    IEEE Conference Publications

    This paper presents a method for predicting radio resource availability in cognitive radio. In this paper, unlike a primary/secondary model, cognitive radio is defined as wireless communication technology in which each node communicates via an optimal wireless system based on recognition of radio resource availability in heterogeneous wireless communication systems. Therefore, it is important to be able to recognize such radio resource availability accurately. However, a cognitive radio node is unable to recognize the subsequent radio resource availability at the time of selecting the optimal wireless system. The authors focus on the prediction of radio resource availability to resolve the above issue. In this paper, the authors focus on IEEE802.11 and radio channel occupation time, which is calculated from packet length and the transmission rate, is used as radio resource availability. From the results of the examination, it would seem feasible that the auto-correlation coefficient (or partial auto-correlation coefficient) could be utilized as information on the reliability of the prediction value when an auto-regression model (AR model) is used for the prediction. Furthermore, by comparing n-step-ahead prediction for a time series calculated for a 1-second interval and 1-step-ahead prediction for a time series calculated for an n-second interval, it is shown that the accuracy of the prediction in both cases is almost identical when the information volume to calculate a prediction expression is the same. Therefore, either prediction approach can be selected depending on the cognitive radio system. View full abstract»

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    Cognitive radio simulation environment realization based on autonomic communication

    Shixian Wang ; Hengzhu Liu ; Lunguo Xie ; Wenmin Hu
    Communication Software and Networks (ICCSN), 2011 IEEE 3rd International Conference on

    DOI: 10.1109/ICCSN.2011.6013743
    Publication Year: 2011 , Page(s): 402 - 407
    Cited by:  Papers (1)

    IEEE Conference Publications

    Cognitive radio has been a research hotspot because of its promise to improve the utilization of the assigned but unused radio spectrum. In order to have such ability, cognitive engine, the intelligent part of cognitive radio, should configure the system to adapt to its communication context. Although much artificial intelligence techniques have been proposed for the cognitive engine realization, this paper proposes an agent based realization method, which had been investigated in the autonomic communication research. Based on the similarity between cognitive radio and autonomic communication, the autonomic cognitive radio conceptual and architecture models are proposed. Cognitive radio nodes realized by the proposed models are easy to form an autonomic cognitive radio network, which can be looked as an autonomic communication environment. The autonomic cognitive radio node is expressed by autonomic communication element (ACE) architecture and a realization method is given based on the open-source ACE toolkit, which establishes a simulation environment for cognitive radio research. View full abstract»

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    A mobility scheme for cognitive radio networks

    Trigui, E. ; Esseghir, M. ; Merghem-Boulahia, L.
    Ad Hoc Networking Workshop (MED-HOC-NET), 2013 12th Annual Mediterranean

    DOI: 10.1109/MedHocNet.2013.6767416
    Publication Year: 2013 , Page(s): 97 - 102

    IEEE Conference Publications

    S Cognitive radio network is a promising wireless network where smart devices are able to opportunistically exploit the spectrum holes and optimize the overall radio spectrum use. The provision of quality of service and mobility management is imperative to providing efficient cognitive radio systems. In this paper, we present a mobility scheme that enables cognitive radio users to seamlessly switch towards the best available spectrum band when moving from one network to another one. On the one hand, our proposal conserves the frequency and the bandwidth needed for users' application. On the other hand, it allows cognitive radio users to have the best band with a good price and a large use duration based on a trading mechanism established between primary and cognitive radio users. Simulation results prove that our approach preserves users' continuity of service during their mobility and ensures high utility for both primary and cognitive radio users. View full abstract»

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    An Encapsulation for Reasoning, Learning, Knowledge Representation, and Reconfiguration Cognitive Radio Elements

    Nolan, K.E. ; Sutton, P. ; Doyle, L.E.
    Cognitive Radio Oriented Wireless Networks and Communications, 2006. 1st International Conference on

    DOI: 10.1109/CROWNCOM.2006.363472
    Publication Year: 2006 , Page(s): 1 - 5
    Cited by:  Papers (3)

    IEEE Conference Publications

    State and contextual awareness, reasoning and conclusions formation, and a means of directing application, structural and parameter-level radio reconfiguration are key elements of a cognitive radio. This paper describes a cognitive radio design capable of scaling between the two extremes of minimal cognitive capabilities and complex highly-evolved cognitive radio abilities, which is being adopted for real tests using licensed cognitive radio test spectrum. A memory element stores state, sensor, objectives, actions and conclusions information and the relevance of this information can be varied in order to identify or ignore common traits or occurrences. The decision-making and conclusions formation abilities of this cognitive radio design can use (or choose to ignore using the variable weighting facility) external information relating to the network, and etiquettes in conjunction with the memory element. A set of actions formulated by the reasoning and conclusions formation stages direct the radio reconfiguration. This design is implemented using a general-purpose processor (GPP) platform as it currently offers the very high level of reconfigurability required for very malleable cognitive radio design View full abstract»

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    Software defined radio based frequency domain chaotic cognitive radio

    Ruolin Zhou ; Xue Li ; Jian Zhang ; Zhiqiang Wu
    SOC Conference (SOCC), 2011 IEEE International

    DOI: 10.1109/SOCC.2011.6085145
    Publication Year: 2011 , Page(s): 259 - 264

    IEEE Conference Publications

    Chaotic communication system has attracted strong interests in high security communication due to robustness in multi-path fading environments, resistance to jamming, and low probability of interception. Recently, cognitive radio has emerged as a strong candidate to solve the spectrum congestion problem by operating over under utilized spectrum bands. Hence, it is highly desired to combine the security advantages of chaos communication with cognitive radio to create a chaotic cognitive radio communication system. However, traditional chaotic communication system is based on time-domain chaotic signal generator where the signal occupies one wide contiguous frequency band, making it inappropriate for cognitive radio applications. To apply the chaotic sequence onto cognitive radio to take advantage of multiple spectrum bands, we generate the chaotic signal in frequency domain. By applying a spectrum mask onto the chaotic signal in frequency-domain, a frequency domain non-contiguous chaotic waveform is created. In this paper, we use universal software radio peripheral and GNU radio software to implement and demonstrate a frequency domain chaotic cognitive radio. This demonstration has several unique features: (1) supporting real-time video transmission; (2) taking advantage of multiple non-contiguous spectrum bands; (3) dynamic cognitive radio waveform adaptation according to the primary user transmissions; (4) maintaining the security features of chaotic communication. View full abstract»

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    Spectrum-aware dynamic channel assignment in cognitive radio networks

    Saleem, Y. ; Bashir, A. ; Ahmed, E. ; Qadir, J. ; Baig, A.
    Emerging Technologies (ICET), 2012 International Conference on

    DOI: 10.1109/ICET.2012.6375468
    Publication Year: 2012 , Page(s): 1 - 6
    Cited by:  Papers (1)

    IEEE Conference Publications

    During the past few years, cognitive radio networks (CRNs) have emerged as a solution for the problems created due to fixed spectrum allocation such as inefficient usage of licensed spectrum. CRNs aim at solving this problem by exploiting the spectrum holes (the spectrum not being used by primary radio nodes at a particular time) and allocating the spectrum dynamically. In this paper, we address the problem of dynamic channel assignment for cognitive radio users in multi-radio multichannel cognitive radio networks (MRMC-CRNs). We propose an efficient spectrum-aware dynamic channel assignment (SA-DCA) strategy for such networks. SA-DCA utilizes available channels and assigns them to multiple radio interfaces of cognitive radio nodes based on primary radio unoccupancy, minimum interference to primary radio nodes, maximum connectivity and minimum interference between cognitive radio nodes. We perform simulations in NS-2 and compare the performance of SA-DCA with two related strategies. Simulation results show that SA-DCA assigns channels efficiently and results in significantly reduced interference to primary radio nodes and increased packet delivery ratio in MRMC-CRNs. View full abstract»

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    Integrated Resource Management in Cognitive Radio

    Marojevic, V. ; Vucevic, N. ; Reves, X. ; Gelonch, A.
    Mobile and Wireless Communications Summit, 2007. 16th IST

    DOI: 10.1109/ISTMWC.2007.4299309
    Publication Year: 2007 , Page(s): 1 - 5
    Cited by:  Papers (1)

    IEEE Conference Publications

    The today's radio environment features a heterogeneous mix of radio access technologies. The technology that facilitates accessing different air interfaces at different times with the same radio equipment is known as software-defined radio (SDR). A cognitive radio system manages the operational modes of SDR equipment as a function of the radio environment. This paper introduces a novel approach to resource management in cognitive radio. We coin it integrated resource management (IRM) because it integrates the management of radio and computing resources. The corresponding system then features two cognitive cycles, the computing cycle and the radio cycle. We demonstrate the suitability of our proposal in a heterogeneous radio and computing scenario. In particular, simulation results show that two simple IRM algorithms can considerably reduce the number of lost user sessions due to inappropriate reconfiguration decisions. The paper concludes that such an integrated resource management, when embedded in a cognitive radio system, can intelligently distribute the radio and computing loads, while adapting to environmental changes. View full abstract»

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    QoE-Driven Channel Allocation Schemes for Multimedia Transmission of Priority-Based Secondary Users over Cognitive Radio Networks

    Tigang Jiang ; Honggang Wang ; Vasilakos, A.V.
    Selected Areas in Communications, IEEE Journal on

    Volume: 30 , Issue: 7
    DOI: 10.1109/JSAC.2012.120807
    Publication Year: 2012 , Page(s): 1215 - 1224
    Cited by:  Papers (4)

    IEEE Journals & Magazines

    With the fast growing of multimedia communication applications, cognitive radio networks have gained the popularity as they can provide high wireless bandwidth and support quality-driven wireless multimedia services. In multimedia applications such as video conferences over the cognitive radio, the Quality of Experience (QoE) that directly measures the satisfaction of the end users cannot be easily realized due to the limited spectrum resources. The opportunistic spectrum access cognitive radio (CR) is an efficient technology to address this issue. However, the unstable channels allocated to the multimedia secondary users (SUs) can be re-occupied by the primary users (PUs) at any time, which makes the CR difficult to meet the QoE requirements. Therefore, it is important to study how to allocate frequency or spectrum resources to SUs according to their QoE requirements. This paper proposes a novel QoE-driven channel allocation scheme for SUs and cognitive radio networks (CRN) base station (BS). The historical QoE data under different primary channels (PCs) are collected by the SUs and delivered to a Cognitive Radio Base Station (CRBS). The CRBS will allocate available channel resources to the SUs based on their QoE expectations and maintain a priority service queue. The modified ON/OFF models of PCs and service queue models of SUs are jointly investigated for this channel allocation scheme. The performance of multimedia transmission of images and H.264 videos under our CR channel allocation scheme is studied, the results show that the proposed channel allocation approach can significantly improve the QoE of the priority-based SUs over the cognitive radio networks. View full abstract»

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    On the Throughput and Spectrum Sensing Enhancement of Opportunistic Spectrum Access Cognitive Radio Networks

    Stotas, S. ; Nallanathan, A.
    Wireless Communications, IEEE Transactions on

    Volume: 11 , Issue: 1
    DOI: 10.1109/TWC.2011.111611.101716
    Publication Year: 2012 , Page(s): 97 - 107
    Cited by:  Papers (4)

    IEEE Journals & Magazines

    Cognitive radio has attracted an increasing amount of interest over the past few years as an effective method of alleviating the spectrum scarcity problem in wireless communications. One of the most promising approaches in cognitive radio is the opportunistic spectrum access, which enables unlicensed users to access licensed frequency bands that are detected to be idle. In this paper, we propose a novel cognitive radio system that exhibits improved throughput and spectrum sensing capabilities compared to the conventional opportunistic spectrum access cognitive radio systems studied so far. More specifically, we study the average achievable throughput of the proposed cognitive radio system under a single high target detection probability constraint, as well as its ergodic throughput under average transmit and interference power constraints, and propose an algorithm that acquires the optimal power allocation strategy and target detection probability, which under the imposed average interference power constraint becomes an additional optimization variable in the ergodic throughput maximization problem. Finally, we provide simulation results, in order to compare the achievable throughput of the proposed cognitive radio system with the respective throughput of the conventional cognitive radio systems and discuss the effects of the optimal power allocation and target detection probability on the ergodic throughput of the proposed cognitive radio system. View full abstract»

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    Cognitive radio antennas that learn and adapt using Neural Networks

    Tawk, Y. ; Costantine, J. ; Al-Zuraiqi, E. ; Christodoulou, C.G.
    Radio Science Meeting (USNC-URSI NRSM), 2013 US National Committee of URSI National

    DOI: 10.1109/USNC-URSI NRSM.2013.6525110
    Publication Year: 2013 , Page(s): 1

    IEEE Conference Publications

    Cognition added to RF/antenna systems has extended software defined radio (SDR) communication systems into cognitive radio systems. Software defined radio has been established as a key enabling technology to realize cognitive radio. Thus a cognitive radio is an SDR that is aware of its environment, and autonomously adjusts its operations to achieve the designated objectives. A cognitive radio system is able to sense, reason, learn and be aware of its environment. A dynamic communication application such as cognitive radio requires antenna researchers to design software controlled reconfigurable antennas. The tuning ability of such antennas and the switching time are important to satisfy the requirements of continuously changing communication channels. Neural Networks (NNs) arose as a perfect candidate to control these antennas through Field Programmable Gate Arrays (FPGAs). NNs represent a perfect solution to add learning and reasoning to the cognitive radio antenna systems. In this work, a NN is applied on a reconfigurable antenna where switches are used to connect and disconnect the different parts of its structure. Reconfigurable antennas are potential candidate for cognitive radio since they are able to change their operating characteristics based on the channel activity. Applying NNs to such antennas result in the association of different antenna configurations with the various frequency responses. This association allows training the NN to be able to configure the antenna and regenerate switch combinations/frequency responses on demand. The NN is built and trained in Matlab Simulink and a Xilinx system generator creates the NN VHDL code to be transferred to the FPGA. The FPGA now controls the switches that are incorporated within the reconfigurable antenna structure. The application of NN on cognitive radio antenna systems allows such systems to react swiftly to any change in their environment. The cognitive radio antennas will regenerate the appropriate swit- h combinations using NN previous training. This will allow communicating over the unoccupied parts of the spectrum which are called white spaces. The dynamic changes that occur in the spectrum require a robust and fast antenna software control. Thus NN prove to be a valid and necessary technique to employ on CR antennas. View full abstract»

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    Leader election algorithm for distributed ad-hoc cognitive radio networks

    Olabiyi, O. ; Annamalai, A. ; Qian, L.
    Consumer Communications and Networking Conference (CCNC), 2012 IEEE

    DOI: 10.1109/CCNC.2012.6181179
    Publication Year: 2012 , Page(s): 859 - 863

    IEEE Conference Publications

    Recent development in wireless communication has necessitated a high demand for radio resources. This has led to the development of cognitive radio technology in which radio equipments are now capable of identifying spectrum opportunity in their environment and take advantage of spectrum unused by licensed primary radio users for communication. One of the derivatives of the emerging technology is the ad hoc cognitive radio networks where control of the network resources is distributed among the users. In order to improve co-ordination in ad hoc cognitive radio networks, there is a need for selection of an appropriate leader that will guarantee quality of service (QoS), spectrum allocation and aggregation and synchronization of cognitive radios. In this paper we proposed a novel leader election algorithm that is robust for distributed ad hoc cognitive radio networks. View full abstract»

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    FMAC: A fair MAC protocol for coexisting cognitive radio networks

    Yanxiao Zhao ; Min Song ; ChunSheng Xin
    INFOCOM, 2013 Proceedings IEEE

    DOI: 10.1109/INFCOM.2013.6566942
    Publication Year: 2013 , Page(s): 1474 - 1482
    Cited by:  Papers (1)

    IEEE Conference Publications

    Cognitive radio is viewed as a disruptive technology innovation to improve spectrum efficiency. The deployment of coexisting cognitive radio networks, however, raises a great challenge to the medium access control (MAC) protocol design. While there have been many MAC protocols developed for cognitive radio networks, most of them have not considered the coexistence of cognitive radio networks, and thus do not provide a mechanism to ensure fair and efficient coexistence of cognitive radio networks. In this paper, we introduce a novel MAC protocol, termed fairness-oriented media access control (FMAC), to address the dynamic availability of channels and achieve fair and efficient coexistence of cognitive radio networks. Different from the existing MACs, FMAC utilizes a three-state spectrum sensing model to distinguish whether a busy channel is being used by a primary user or a secondary user from an adjacent cognitive radio network. As a result, secondary users from coexisting cognitive radio networks are able to share the channel together, and hence to achieve fair and efficient coexistence. We develop an analytical model using two-level Markov chain to analyze the performance of FMAC including throughput and fairness. Numerical results verify that FMAC is able to significantly improve the fairness of coexisting cognitive radio networks while maintaining a high throughput. View full abstract»

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    Enhancing the Capacity of Spectrum Sharing Cognitive Radio Networks

    Stotas, S. ; Nallanathan, A.
    Vehicular Technology, IEEE Transactions on

    Volume: 60 , Issue: 8
    DOI: 10.1109/TVT.2011.2165306
    Publication Year: 2011 , Page(s): 3768 - 3779
    Cited by:  Papers (6)

    IEEE Journals & Magazines

    Spectrum sharing has attracted a lot of attention in cognitive radio recently as an effective method of alleviating the spectrum scarcity problem by allowing unlicensed users to coexist with licensed users under the condition of protecting the latter from harmful interference. In this paper, we focus on the throughput maximization of spectrum sharing cognitive radio networks and propose a novel cognitive radio system that significantly improves their achievable throughput. More specifically, we introduce a novel receiver and frame structure for spectrum sharing cognitive radio networks and study the problem of deriving the optimal power allocation strategy that maximizes the ergodic capacity of the proposed cognitive radio system under average transmit and interference power constraints. In addition, we study the outage capacity of the proposed cognitive radio system under various constraints that include average transmit and interference power constraints, and peak interference power constraints. Finally, we provide simulation results, in order to demonstrate the improved ergodic and outage throughput achieved by the proposed cognitive radio system compared to conventional spectrum sharing cognitive radio systems. View full abstract»

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    DDH-MAC: A novel Dynamic De-Centralized Hybrid MAC protocol for Cognitive Radio Networks

    Shah, M.A. ; Safdar, G.A. ; Maple, C.
    Roedunet International Conference (RoEduNet), 2011 10th

    DOI: 10.1109/RoEduNet.2011.5993685
    Publication Year: 2011 , Page(s): 1 - 6
    Cited by:  Papers (2)

    IEEE Conference Publications

    The radio spectrum (3kHz - 300GHz) has become saturated and proven to be insufficient to address the proliferation of new wireless applications. Cognitive Radio Technology which is an opportunistic network and is equipped with fully programmable wireless devices that empowers the network by OODA cycle and then make intelligent decisions by adapting their MAC and physical layer characteristics such as waveform, has appeared to be the only solution for current low spectrum availability and under utilization problem. In this paper a novel Dynamic De-Centralized Hybrid “DDH-MAC” protocol for Cognitive Radio Networks has been presented which lies between Global Common Control Channel (GCCC) and non-GCCC categories of cognitive radio MAC protocols. DDH-MAC is equipped with the best features of GCCC MAC protocols but also overcomes the saturation and security issues in GCCC. To the best of authors' knowledge, DDH-MAC is the first protocol which is hybrid between GCCC and non-GCCC family of protocols. DDH-MAC provides multiple levels of security and partially use GCCC to transmit beacon which sets and announces local control channel for exchange of free channel list (FCL) sensed by the co-operatively communicating cognitive radio nodes, subsequently providing secure transactions among participating nodes over the decided local control channel. This paper describes the framework of the DDH-MAC protocol in addition to its pseudo code for implementation; it is shown that the pre-transmission time for DDH-MAC is on average 20% better while compared to other cognitive radio MAC protocols. View full abstract»

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    Multiband fractal antenna design for Cognitive radio applications

    Nayak, P.B. ; Verma, S. ; Kumar, P.
    Signal Processing and Communication (ICSC), 2013 International Conference on

    DOI: 10.1109/ICSPCom.2013.6719767
    Publication Year: 2013 , Page(s): 115 - 120

    IEEE Conference Publications

    Rapid development in wireless communication systems and an increase in the number of users of wireless devices is bound to result in spectrum shortage in the near future. The concept of Cognitive radio is envisaged to be a paradigm of new methodologies for achieving performance enhanced radio communication system through an efficient utilization of available spectrum. Research on antenna design is very critical for the implementation of cognitive radio. A special antenna is required in cognitive radio for sensing and communication purposes. This papers investigates the use of multiband fractal antennas for spectrum sensing application in cognitive radio units. The performance of a new fractal antenna design which generates four bands of operation in the range of 900-4000 MHz has also been studied. Through a thorough discussion on its return loss and radiation plots as well as other parameters such as gain and radiation efficiency, it is proved that the it is a promising antenna for future cognitive radio systems. View full abstract»

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    Building a cognitive radio network testbed

    Zhe Chen ; Nan Guo ; Qiu, R.C.
    Southeastcon, 2011 Proceedings of IEEE

    DOI: 10.1109/SECON.2011.5752912
    Publication Year: 2011 , Page(s): 91 - 96
    Cited by:  Papers (5)

    IEEE Conference Publications

    Cognitive radio has been put forward to make efficient use of scarce radio frequency spectrum. A testbed for cognitive radio can not only verify concepts, algorithms, and protocols, but also dig out more practical problems for future research. However, to our best knowledge, an authentic real-time cognitive radio system has never been demonstrated. In order to build a cognitive radio network testbed, four popular commercial off-the-shelf hardware platforms are investigated. Unfortunately, none of them meets our needs. Thus, an architecture of the motherboard and a functional architecture for nodes of cognitive radio network testbeds, as well as an architecture for cognitive radio network testbeds, are proposed. With the proposed architectures, a cognitive radio network testbed is being built at Tennessee Technological University. View full abstract»

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