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3G Mobile Communication Technologies, 2000. First International Conference on (Conf. Publ. No. 471)

Date 2000

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Displaying Results 1 - 25 of 94
  • Analysis of integrated voice and data for GPRS

    Publication Year: 2000 , Page(s): 436 - 440
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    In multimedia mobile communications, several type of services such as voice, WWW, FTP with different quality of services are to be supported. Some services like voice are delay-sensitive, whereas the other can tolerate more delay. Based on different QoS, the scheme of sharing the radio resources plays an important role in network dimensioning. We present a new analysis for integrated services consisting of voice and data based on a TDMA system. All resources can be shared by users, however voice has priority with pre-emption. The service policy for data users is FCFS and voice traffic cannot be buffered. The exact analysis have been applied to the General Packet Radio Services (GPRS) and the data support capability of GPRS for a range of available channels and GoS are presented View full abstract»

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  • Network planning and optimization in the third generation wireless networks

    Publication Year: 2000 , Page(s): 441 - 445
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (360 KB)  

    We review the technical challenges and requirements of network planning and optimization techniques for third generation wireless systems. In particular, we highlight the key differences of network planning techniques for second generation and third generation wireless networks. Moreover, we propose a new approach to wireless network design in which the physical characteristics of wireless systems in addition to network configuration are taken into account View full abstract»

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  • Effects of synchronisation and asymmetry in UTRA-TDD

    Publication Year: 2000 , Page(s): 86 - 88
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    We study the interference suffered by UTRA-TDD systems taking into account synchronisation and asymmetry factors. The main conclusion from the simulation results is that the interference between base stations is potentially one of the most serious problems in the UTRA-TDD system View full abstract»

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  • Wideband flexible microwave radio-steps towards the software radio

    Publication Year: 2000 , Page(s): 336 - 340
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    The paper discusses the design and development of a microwave radio transceiver at 1.4 GHz, which implements multirate signal processing algorithms to provide variable channel bandwidths, symbol rates on the channel, two constellation PSK modulation schemes, and wide frequency tuning range using fractional-N synthesis to achieve fine frequency resolution and low noise. To avoid RF switching, there is no analogue channel filtering, where all adjacent and some spurious blocking is achieved in the digital baseband circuits. The requirements on receiver and transmitter linearity, filtering requirements, ADC/DAC performance are discussed and analysed, and conclusions applied to future third generation and possible dual-mode software mobile radios. The paper focuses on the practical implementation of software radio techniques and practical results are discussed View full abstract»

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  • CDMA mobile systems with tailor made power control to each mobile station

    Publication Year: 2000 , Page(s): 46 - 50
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (480 KB)  

    Power control is an important issue in the capacity of DS-CDMA cellular systems to tackle the near-far problem, co-channel interference and varying signal strength in fading channels. In this paper, we propose an adaptive signal-interference-ratio (SIR) feedback power control technique so that the SIR threshold control level of each mobile station will be individually adjusted with respect to its own radio link condition. Fuzzy logic control is applied to the power control and the SIR threshold level in this paper. This new technique results in lower outage probability and thus enhances traffic capacity, especially in poor cochannel interference conditions View full abstract»

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  • Performance analysis of ESPRIT, TLS-ESPRIT and Unitary-ESPRIT algorithms for DOA estimation in a W-CDMA mobile system

    Publication Year: 2000 , Page(s): 200 - 203
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    The performance of ESPRIT, TLS-ESPRIT and Unitary-ESPRIT for direction-of-arrival (DOA) estimation is evaluated in terms of the mean DOA error. The algorithms are applied at a base station (BS) on the uplink of a W-CDMA (wideband-code division multiple access) signal transmitted by a mobile station (MS) in a number of representative propagation scenarios View full abstract»

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  • Dynamic pricing in mobile communication systems

    Publication Year: 2000 , Page(s): 416 - 420
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (492 KB)  

    The mobile cellular telephony market has expanded rapidly over the past decade. In the UK, at the end of the first quarter of 1999, mobile phone penetration was almost 30%-up by 5% compared to the end of 1998. This rapid growth has been mainly due to aggressive marketing and the level of competition between service providers, which led to a reduction in call charges. In turn, the increased demand for network services has led to substantial investments in the network infrastructure. Given that the radio frequency band allocated to GSM and UMTS is limited, the obvious solution to increase available capacity is through cell splitting and frequency re-use, resulting in smaller cell clusters. A certain degree of flexibility in handling the number of available channels per cell could be achieved by either: moving capacity between cells (dynamic channel allocation). Another option for optimising the available network capacity is alternate routing. In this context, real-time or dynamic pricing (the variation of tariff according to system utilisation) could potentially provide an additional strategy for efficient use of available scheme. This article begins with a literature review of applications of dynamic pricing in fixed telephony and other industries. Then an algorithm for the application of dynamic pricing to cellular networks is suggested and a model depicting user behaviour is presented. Finally, results from a set of simulations, incorporating a user behaviour model are presented View full abstract»

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  • Performance analysis of reverse link wideband CDMA cellular system under fast closed-loop power

    Publication Year: 2000 , Page(s): 51 - 55
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (332 KB)  

    Performance of a reverse link wideband CDMA cellular system with fast closed-loop power control is studied in this paper. The channel is modelled as frequency selective fading. The probability of bit error, P c, is used as the performance criterion. A mathematical formulation is derived which takes into consideration the updating frequency of the power control mechanism, the fading rate of the channel, the number of resolvable multipaths, number of RAKE receiver branches, number of simultaneous users and the processing gain. The interaction between these parameters and the Pc performance is studied. The frequently assumed log-normal approximation of the received signal power has also been verified to be valid in the range of 10-3⩽Pc⩽0.5 provided the number of simultaneous users that is allowed in the system K⩾8. Finally, the analysis shows that the received signal power estimation error is the major cause of degradation in the Pc performance View full abstract»

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  • Terminal reconfigureability-the software download aspect

    Publication Year: 2000 , Page(s): 326 - 330
    Cited by:  Papers (2)  |  Patents (19)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (500 KB)  

    The reconfigureability of software radios provides the means to alter hardware and software settings within a mobile terminal and therefore requires the secure and reliable download of configuration software from any possible software source. This paper presents a viable software download protocol and describes the requirements on the supporting infrastructure. A detailed signalling message sequence necessary to perform these download sessions is presented and the list of required messages is also provided. Finally, the paper presents the description of a platform independent model implementation for the proposed download procedure View full abstract»

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  • A novel closed loop power control for UMTS

    Publication Year: 2000 , Page(s): 56 - 59
    Cited by:  Papers (8)  |  Patents (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (324 KB)  

    Wideband CDMA has been selected as the access technique for the next generation communication system. Consequently, it has received a significant amount of attention in provision of advanced algorithms for improved performance. Accurate power control is one the most important requirements of the CDMA systems. In this paper, two new adaptive step-size algorithms for controlling the transmitted power of the mobile stations in a CDMA-based cellular system are presented. The performance of the two algorithms are compared with that of the conventional and their superiority clearly demonstrated View full abstract»

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  • W-CDMA reception with a DSP based software radio

    Publication Year: 2000 , Page(s): 311 - 315
    Cited by:  Patents (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    With the increasing number of mobile-phone standards there is a demand for a software-based radio for use in base-stations that can adapt to many standards. This paper discusses how to implement a RAKE receiver in a high performance standard DSP that can search out the multiple paths and combine them to demodulate the received data. To perform a complete search for a mobile within a cell there will typically be 8000 potential radio delay paths of which only a small number (3-6) will actually contain any useful data. However as each path contains 5120 chips of data the correlation exercise necessary to find these paths is a very MIPS intensive task. The paper highlights a number of techniques based on rough data on the mobiles whereabouts from the initial random link and information on the relationship between the samples to perform an intelligent simplified search that will still find the paths. This allows a much smaller subset to be searched initially of 512 delay paths and 1536 chips making the task simple enough for a DSP based RAKE receiver implemented on a single TMS320C62xx with a 100 MHz-search engine and receive data using a 6-finger RAKE receiver at 58 MHz View full abstract»

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  • Co-channel interference cancellation techniques for antenna array assisted multiuser OFDM systems

    Publication Year: 2000 , Page(s): 256 - 260
    Cited by:  Papers (8)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (476 KB)  

    Minimum mean square error (MMSE)-based multiple-antenna assisted co-channel interference suppression/space division multiple access (SDMA) schemes designed for OFDM have drawn wide interest. In this article, parallel interference cancellation (PIC) is proposed and studied in comparison to maximum likelihood sequence estimation (MLSE) based schemes. The best design trade-off was constituted by the successive interference cancellation (SIC) schemes View full abstract»

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  • Integration of experimentally measured propagation data into system simulations

    Publication Year: 2000 , Page(s): 11 - 13
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (212 KB)  

    The current interest in the development of third generation cellular radio systems has focused attention on propagation channel issues. CDMA systems occupy wide bandwidths, which typically exceed the channel coherence bandwidth, leading to severe frequency selective distortion. Extensive channel sounding campaigns have been carried out, and much data gathered, from which statistics may be derived to characterise these channels. These statistics may then be employed within generalised channel simulation software in non-real time, or within hardware channel emulators in real time. In this paper we consider an alternative method where channel sounding data may be accepted by a system simulation tool, which then predicts the performance of a particular radio system configuration. Benefits of this approach include simplicity, as reduction of the channel data to statistical parameters is not required, and realism as the actual recorded data is utilised View full abstract»

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  • The effects of inter-system interference in UMTS at 1920 MHz

    Publication Year: 2000 , Page(s): 103 - 107
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (432 KB)  

    The Universal Mobile Telecommunications System (UMTS) is composed of an FDD and TDD mode. Both modes have an adjacent carrier at 1920 MHz. The implications thereof for system capacity are analysed. In this context, the FDD mode is assumed to account for full spatial coverage and the TDD mode is employed to cover areas with increased traffic `hot spots'. The separation distance of the TDD and FDD base station (BS) and the load in each system are varied. It is shown that the capacity in the FDD system is reduced by less than 5% for a BS separation distance greater than 300 m. Contrary to this, the capacity reduction in the TDD system is only below 5% for a BS separation of less than 1000 m. This clearly yields a trade-off which limits the degree of freedom in planning the network in this particular case View full abstract»

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  • Data multiplexing strategies for mobile applications

    Publication Year: 2000 , Page(s): 421 - 425
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (380 KB)  

    There is an increasing demand for sending different types of data over mobile communication systems. Sending different types of data simultaneously requires some multiplexing strategy. This paper focuses on multiplexing strategies for mobile applications to transmit different types of data. Here we propose several modifications to the ITU H.223 multiplexing standard, which makes communications more reliable. Also, we propose strategies for multiplexing time critical data View full abstract»

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  • Linear multi-user detectors for TDD mode of UMTS (IMT-TC)

    Publication Year: 2000 , Page(s): 99 - 102
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (264 KB)  

    We have examined the effect of multi-user detectors for the TDD mode of wideband CDMA, particularly the downlink. It is shown that under dispersive conditions a RAKE receiver suffers from a high mean square error at its output when all the codes are used in parallel and is not particularly suitable for high levels of QAM. Generally it is not possible to use the CDMA channel at a user bit rate which approaches the Shannon capacity. A MUD demodulator on the other hand restores the output MSE to within 1 dB of what would occur in an ideal channel and can offer a much higher bit rate. The average DSP load for downlink MUD detectors is modest and it is reasonable to consider their use in nomadic and portable instruments such as hand held portables or lap-tops computers with wireless modems View full abstract»

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  • A handover algorithm support for multimedia service provision in heterogeneous packet-oriented mobile environments

    Publication Year: 2000 , Page(s): 240 - 244
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (412 KB)  

    Third generation mobile communication systems will provide multimedia services across heterogeneous mobile networks and will need to support seamless mobility in a more flexible and intelligent manner than previous generations. As the main components under the third generation mobile communications system, UMTS and GPRS (an intermediate second generation GSM evolution) will support packet-switched services. An interesting future scenario could be the handover between GPRS and UMTS, providing seamless service connectivity to the user. In such an environment, existing handover algorithms may not meet the requirements of providing seamless handover. A graceful adaptation to quality of service (QoS) variations due to network heterogeneity is deemed necessary. In this paper, we consider the problem of providing seamless or nearly seamless handover between GPRS and UMTS. Assuming a mobile controlled handover algorithm, the handover connection management functional model, consisting of two main components: the handover control entities and the QoS control entities, is then derived. The network architecture is then identified for the mobile scenario under investigation. The functional model is then mapped onto the network architecture to provide the functional architecture from which the handover signalling protocol and the information flows of the chosen handover algorithm are derived View full abstract»

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  • Secure interoperation between 2G and 3G mobile radio networks

    Publication Year: 2000 , Page(s): 28 - 32
    Cited by:  Papers (3)  |  Patents (8)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    Interoperation of 2G and 3G networks will be an important issue when both kinds of networks will exist in parallel and need to interwork with each other. Among other things, this implies that 2G subscribers should be able to access 3G networks by means of a 2G SIM card and a dual-mode handset. However, it is well known that 3G networks will offer its users an increased level of security when compared to 2G networks. For example, in 3G networks there will be mutual authentication between user and network as well as integrity protection of signalling commands on the air interface, with an associated 128 bit integrity key. Also the 3G cipher key will be 128 bit long, as opposed to the 2G cipher key of 64 bit length. The paper concentrates on the security aspects of 2G and 3G interworking. We identify all relevant roaming and handover cases between 2G and 3G networks and describe the solution for handling the cipher and integrity keys in these cases developed by the 3GPP security group, which is the relevant standardisation body. The guiding principle was to provide 3G security to 3G users whenever possible. The solution is assessed with respect to the security it offers and the signalling load it causes View full abstract»

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  • Resource management issues for UMTS

    Publication Year: 2000 , Page(s): 401 - 405
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    One of the most important aspects of third generation systems employing W-CDMA is resource management, which should regulate the operation of a network in such a way that ensures the uninterrupted service provision to the existing connections and at the same time accommodates in an optimum way the new connection requests. This article presents issues concerning resource management and call admission control (CAC) for multimedia W-CDMA systems. It discusses the main factors that affect the capacity of such a network based on the generation of multiple access interference (MAI), on the mobile terminal power limitations and on propagation conditions. The aggregation of different services with different characteristics (bit rate, duty cycle, circuit/packet switching) and QoS requirements (BER, delay) are analysed. The CAC scheme presented is based on the maximum transmitted power by the mobile terminal which attempts to mitigate propagation channel impairments and the effect of MAI generated in the same and other cells. Different models are used for each service to take into account the discontinuous transmission of speech, the variable bit rate of video and the self-similar nature of WWW traffic View full abstract»

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  • Simulation results and interference cancellation in UMTS downlink receiver

    Publication Year: 2000 , Page(s): 266 - 270
    Cited by:  Papers (1)  |  Patents (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (260 KB)  

    We present here the results of the simulation trials in the UMTS downlink receiver. An SPW implementation of the downlink system is built and analyzed. A RAKE receiver with multiple fingers is employed in the UMTS downlink receiver to take advantage of the multipath channel. Each finger within the receiver performs channel estimation to obtain the channel coefficients. Performance curves for the receiver for the two path and four path channel models are provided. The presence of multipath destroys the orthogonality among the various channels and this invariably results in interference in the detection of the desired signal. Here, we investigate, an interference cancellation scheme whose performance improvement is studied through end-to-end simulations View full abstract»

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  • Sectorization gain in CDMA cellular systems

    Publication Year: 2000 , Page(s): 70 - 75
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    This paper presents an analytical method for estimation of sectorization gain in CDMA cellular systems. Non-ideal antenna radiation patterns are investigated in order to identify the factors which limit the sectorization gain. These include environment related factors, i.e. path loss exponent and standard deviation of shadowing, handover schemes i.e. hard, soft and soft/softer handovers, and different non-ideal sectorized antenna radiation patterns such as a nearly-ideal radiation pattern and a practical radiation pattern. The numerical results show that the sectorization gain is influenced by all the above factors. The effect is more considerable when soft or soft/softer schemes are deployed in the system View full abstract»

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  • A new development system for reconfigurable digital signal processing

    Publication Year: 2000 , Page(s): 306 - 310
    Cited by:  Patents (48)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (416 KB)  

    Requirements for future mobile communications systems are demanding. This paper presents techniques and a development system for the research, design & development of reconfigurable digital signal processing for software radio based systems. Software radio is an essential technology required for the realisation of 3G to meet requirements such as seamless global roaming and protocol independence. This development system ensures that the use of FPGA is practical and realistic when considering the high data rate and multifunctional requirements of 3G systems View full abstract»

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  • W-CDMA capacity analysis using GIS based planning tools and MATLAB simulation

    Publication Year: 2000 , Page(s): 230 - 234
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (460 KB)  

    The evolution of cellular systems towards third generation (3G) or IMT-2000 seems to have a tendency to use W-CDMA as the standard access method, as ETSI decisions have showed. However, there is a question about the improvements in capacity and the wellness of this access method. One of the aspects that worry developers and researchers planning the third generation is the extended use of the Internet and more and more bandwidth hungry applications. This work shows the performance of a W-CDMA system simulated in a PC using cover maps generated with DC-Cell, a GIS based planning tool developed by the Technical University of Valencia, Spain. The maps are exported to MATLAB and used in the model. The system used consists of several microcells in a downtown area. We analyse the interference from users in the same cell and in adjacent cells and the effect in the system, assuming perfect control for each cell. The traffic generated by the simulator is voice and data. This model allows us to work with coverage that is more accurate and is a good approach to analyse the multiple access interference (MAI) problem in microcellular systems with irregular coverage. Finally, we compare the results obtained, with the performance of a similar system using TDMA View full abstract»

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  • Novel and enhanced mobile Internet protocol for third generation cellular environments compared to MIP and MIP-LR

    Publication Year: 2000 , Page(s): 143 - 147
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (452 KB)  

    The mobile Internet protocol (MIP) is an extension for Internet protocol version 4 (IPv4) providing the capability to move between IP subnets without losing any Internet connectivity, which is important for handoffs between cells in wireless environments. However, currently due to the design the MIP suffers from issues such as performance regarding handoffs and interoperability with protocols such as RSVP for providing quality of service (QoS). To overcome the problems of MIP the suggested architecture of Jain (see IEEE Transaction on Networking, 1999, and Proc. ICC'98, 1998) has been implemented, enhanced and tested on Windows 2000. We call this enhancement of MIP based on the solution using home location registries the Itinerant Internet Protocol (IIP). Tests show that IIP outperforms MIP in respect of handoffs. Its design does not require encapsulation and mobility agents like MIP. It does not suffer triangular routing and eliminates the necessity of periodic routing advertisement. Due to the design it is best suited to third generation wireless cellular networks such as UMTS. The cost of the advantages are that all hosts that want to communicate with the mobile hosts need to be mobile aware i.e. they need to have a mobile aware protocol stack implemented. We describe and compare MTP and ITP. The designed interaction of IIP used with UMTS is pointed out. We also present tests and discuss the results that prove the significant quicker handoffs of IIP compared to MIP View full abstract»

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  • Multipath fading simulation for design verification in digital baseband domain

    Publication Year: 2000 , Page(s): 376 - 380
    Cited by:  Patents (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    The coming 3rd generation WCDMA systems are moving the focus of receiver and transmitter design towards powerful digital baseband signal processing. This change poses new requirements for multipath fading simulators used in R&D, validation and type approval tests. The key new requirements are the capability of simulating semi-real time signals and the introduction of a new physical interface layer-digital baseband. To facilitate these requirements full digital implementation of the multipath fading simulator is needed View full abstract»

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