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Proceedings of ICUPC 97 - 6th International Conference on Universal Personal Communications

12-16 Oct. 1997

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  • 1997 IEEE 6th International Conference on Universal Personal Communications Record

    Publication Year: 1997, Page(s):i - xxvii
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    Freely Available from IEEE
  • Author index

    Publication Year: 1997, Page(s):934 - 936
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    Freely Available from IEEE
  • Modified Wiener beamforming for indoor multipath channels

    Publication Year: 1997, Page(s):823 - 827 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    The impulse response of an indoor channel varies for different environments and spatial positions of a transceiver pair as a function of the phase relationship among individual multipath components that have a variety of time delays. These cause fading especially within chip durations of DS-CDMA systems. We propose modified Wiener beamforming (MWB) to co-phase the multipath components then combine... View full abstract»

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  • Path diversity reception using steering vector arrays and MLSE for frequency-selective fading channels

    Publication Year: 1997, Page(s):818 - 822 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    In this paper, the path diversity reception using steering vector arrays and a maximum likelihood sequence estimator is proposed to cope with frequency-selective fading. The proposed scheme extracts the direct path and the 1-symbol delayed path separately using the two sets of the single constraint least mean square steering vector array. It combines the array output signals with the branch metric... View full abstract»

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  • Power control based on adaptive prediction in the CDMA/TDD system

    Publication Year: 1997, Page(s):790 - 794 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    An open-loop power control scheme in the CDMA/TDD system is presented, which is based on the adaptive prediction of the multipath fading channel. The linear and nonlinear adaptive prediction filters are studied. Computer simulations show that this scheme can achieve the precise power control even in the worse fading channel, and the Volterra based nonlinear filter provides the optimum performance View full abstract»

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  • Complexity reduction with generalized Viterbi decoding for IS-95A forward link

    Publication Year: 1997, Page(s):376 - 380 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    We present a modified decoding structure for the forward link of IS-95A. The new method employs generalized Viterbi decoding which results in reduced complexity with little degradation in the overall link performance. The results are provided for AWGN and Rayleigh fading channel models. Single and two path soft-handoff cases are also considered for different mobile speeds. Approximately 50% comple... View full abstract»

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  • Stored media synchronization schemes in ATM and wireless networks: a performance comparison

    Publication Year: 1997, Page(s):766 - 772 vol.2
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (716 KB)

    This paper compares four schemes of lip synchronization control between voice and video for stored media transmission. Two out of the four interleave voice and video to form a single transport stream for transmission (single-stream approach). The other two set up separate transport streams for the individual media streams (multi-stream approach). In each of the two approaches, we have the alternat... View full abstract»

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  • An adaptive hybrid FEC/ARQ protocol using turbo codes

    Publication Year: 1997, Page(s):541 - 545 vol.2
    Cited by:  Papers (5)  |  Patents (31)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    This paper describes a type-II adaptive hybrid FEC/ARQ protocol using turbo codes. Both voice and data services are considered. Recently, a powerful family of error correcting codes using parallel concatenated convolutional codes is introduced. Near-Shannon-limit is achievable by such codes. For example, a bit error rate of 10-5 ; can be achieved at Eb/No 0.7 dB us... View full abstract»

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  • TDD-CDMA extension to FDD-CDMA based third generation cellular system

    Publication Year: 1997, Page(s):813 - 817 vol.2
    Cited by:  Papers (8)  |  Patents (39)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    A TDD-CDMA extension for a FDD-CDMA based third generation cellular system is considered in this paper, A system scenario is presented where frequency bands allocated to time division duplex (TDD) operation can be effectively utilized in complementing the services and increasing the capacity provided by a wide area coverage frequency division duplex (FDD) system. A flexible and simple TDD air inte... View full abstract»

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  • On the capacity of W-CDMA system with different bandwidths in a realistic mobile channel

    Publication Year: 1997, Page(s):613 - 617 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    The capacity of an asynchronous CDMA system having different bandwidths of 1 MHz, 5 MHz, and 10 MHz is analyzed and compared with each other over a realistic mobile radio channel. It is assumed that the CDMA system undergoes Rician fading having a Rice parameter corresponding to the system bandwidth. By using measured data, the Rice parameter which accounts for the effects of multipath fading is e... View full abstract»

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  • Postdetection maximal ratio combining diversity receiver with scalar phase signals

    Publication Year: 1997, Page(s):391 - 395 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    This paper proposes 2-branch and 4-branch postdetection maximal ratio combining (MRC) diversity receivers that offer sufficient diversity gain and sharply reduced hardware size. The proposed receivers utilize the scalar phase signals, which are the output signal of the demodulator of each branch, and some ROM tables. No multipliers, which require a large hardware size, are used. Computer simulatio... View full abstract»

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  • Power control in the DECT radio local loop

    Publication Year: 1997, Page(s):785 - 789 vol.2
    Cited by:  Papers (5)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    On fixed networks communications it is worth to note that the most expensive inversions are on the user local loop more than into the network architecture. Traditionally, the user local loop has been implemented using copper cables, in order to reduce costs other alternatives are being studied and particularly the radio local loop (RLL). We focus on the Digital Enhanced Cordless Telecommunications... View full abstract»

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  • The mobile ATM LAN emulation protocol

    Publication Year: 1997, Page(s):416 - 420 vol.2
    Cited by:  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (564 KB)

    We propose the mobile ATM LAN emulation protocol (MLE) which is an extension of the ATM Forum LAN emulation (LE) protocol. MLE provides a location independent access and allows user to move around within wired or wireless ATM LAN without interruption to the LE services. The proposed protocol takes advantage of the fact that VCCs used for LAN emulation are established and relinquished on demand. Th... View full abstract»

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  • Effects of gain and phase imbalance on sum-difference code tracking loop's performance in spread spectrum systems

    Publication Year: 1997, Page(s):371 - 375 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    The nonlinear renewal process approach (RPA) is applied to analyze the noncoherent sum-difference loop (SDL) with gain and phase imbalance for spread spectrum systems. In the analysis, the code acquisition boundary is equal to the branch offset, 0<δ⩽1. The results indicate that under phase imbalance, when δ⩾0.5 and with gain balance, the values of the DC bias of the SDL are ... View full abstract»

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  • Comparison of orthogonal CDMA and slow frequency hopping (SFH)/TDMA for picocell communications on the basis of spectral efficiency and robustness

    Publication Year: 1997, Page(s):859 - 863 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    In this analysis, the effects of co-channel interference, unintentional interference and fading on an orthogonal (O)CDMA and a slow frequency hopping (SFH)/TDMA are investigated. Both OCDMA and SFH/TDMA are small cell, low mobility systems without low-rate speech coding and other complex baseband signal processing. Further, time division duplexing (TDD) rather than frequency division duplexing (FD... View full abstract»

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  • Bandwidth reservation for multimedia traffic over micro cellular network

    Publication Year: 1997, Page(s):761 - 765 vol.2
    Cited by:  Papers (4)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    Supporting multimedia traffic over wireless channels in a cellular network requires effective control of the channel's limited capacity. The challenge is to guarantee different quality of service (QoS) parameters for different types of traffic while achieving high throughput. The performance of a bandwidth reservation multiple access (BRMA) protocol is studied for multimedia traffic. BRMA reserves... View full abstract»

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  • Packet dropping statistics of a data-link protocol for wireless local communications

    Publication Year: 1997, Page(s):536 - 540 vol.2
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    We consider a data transmission system over a wireless channel, where packets are queued at the transmitter ARQ is employed as the error control scheme, by which packets corrupted due to channel impairments are immediately retransmitted. We study the statistics of the packet dropping process due to buffer overflow. In particular, we propose a Markov approximation to model such losses. The delay pe... View full abstract»

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  • Statistical nature of behavior and performance of DS-CDMA cellular mobile communications

    Publication Year: 1997, Page(s):809 - 812 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    In this paper, the statistical nature of DS-CDMA cellular radio systems is studied. Many different behaviors of the system result from its statistical nature. Since DS-CDMA is an averaging method, In a qualitative discussion about it, the average behavior of the system is usually considered. But, the capacity criterion is usually the 1st percentile of the `C/I' (carrier to interference ratio) dist... View full abstract»

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  • Performance evaluation of type-of-service based directed retry strategy in cellular mobile networks

    Publication Year: 1997, Page(s):676 - 680 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    Type-of-service based directed retry strategy is investigated to achieve efficient channel utilization for different types of users in mobile cellular environments. Directed retry takes advantage of inevitable overlap among cells to increase the channel utilization and reduce the blocking probability in each cell. A M/M/m/k queue is used to model the channel occupancy statement. Several parameters... View full abstract»

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  • Natural hidden terminal and the performance of the wireless LANs

    Publication Year: 1997, Page(s):929 - 933 vol.2
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (508 KB)

    If the access point (AP) and all the mobile terminals have the same coverage, there will always be terminals in the coverage area of the AP which are hidden to one another. This phenomenon is referred to as the natural hidden terminal problem. We analyze the impact of the natural hidden terminals on the throughput of a wireless LAN consisting of mobile terminals distributed around an AP. The analy... View full abstract»

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  • A simple algorithm for asymptotically optimal reduced-state sequence estimation

    Publication Year: 1997, Page(s):718 - 722 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    A simple algorithm for reduced-state sequence estimation on channels with intersymbol interference is presented. The algorithm is based on the conventional Viterbi algorithm. The number of states is reduced by discarding trellis-paths based on their (modified) path metric and the minimum Euclidean distance in the trellis. An analysis of the error-event probability shows that the algorithm achieves... View full abstract»

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  • Performance of FFH-GMSK signals with centre sampling double differential detection in frequency-selective Rayleigh channels with CCI

    Publication Year: 1997, Page(s):480 - 484 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    It is well known that classical (single) differential detection systems yield poor performance for channels that introduce into the carrier a random frequency shift, such as mobile radio (MR) channels. In such situations, one must resort to a form of differential detection (DD) that has the capability to remove the effect of frequency variations. This paper studies the performance of a centre samp... View full abstract»

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  • Capacity analysis of a CDMA cellular system with power control schemes

    Publication Year: 1997, Page(s):608 - 612 vol.2
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (416 KB)

    We develop a general model to study the forward link capacity of a CDMA cellular system with power control. Using this model, two forward link power control schemes (nth-power-of-distance power control scheme and optimum power control scheme) are examined. The increase in capacity by using power control has been studied. The capacity of the forward link is also compared with that of the reverse li... View full abstract»

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  • Analysis of a simple PCS network with nonuniformly distributed mobile users

    Publication Year: 1997, Page(s):572 - 576 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (436 KB)

    A traffic performance model and analytical method are proposed for mobile communication systems that have nonuniform offered traffic. Nonuniformity of user distribution should be taken into account when a system is designed. New system state variables are introduced to analyze such situations. These represent the number of active calls of each kind as well as their moving directions and hand-off e... View full abstract»

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  • The effectiveness of preselection diversity for indoor wireless systems

    Publication Year: 1997, Page(s):386 - 390 vol.2
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (684 KB)

    This paper presents the experimental results of an investigation into the effectiveness of preselection diversity in an indoor 900 MHz TDMA system. We show that a simple auxiliary antenna, used in conjunction with the standard λ/4 whip on a cellular handset, delivers nearly a 10 dB improvement in signal level in fades that occur 1% of the time, compared to one antenna. Our studies also show... View full abstract»

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