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
  • 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 (425 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/sup -5/; can be achieved at E/sub b//N/sub o/ 0.7 dB using a rate 1/2 c... View full abstract»

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  • Author index

    Publication Year: 1997, Page(s):934 - 936
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    Freely Available from IEEE
  • An embedded cryptosystem for digital broadcasting

    Publication Year: 1997, Page(s):401 - 405 vol.2
    Cited by:  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (528 KB)

    Current day multimedia systems require secure, reliable and fast data transfer. Conventional cryptographic systems attempt to encrypt the entire data directly, thereby requiring significant computation and noise free channels. This makes existing methods less attractive for real time broadcasting. Spread spectrum techniques offer good noise immunity over multiple access channels. We propose a new ... View full abstract»

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  • Cutoff rate performance for space diversity systems in Rayleigh fading channels without CSI

    Publication Year: 1997, Page(s):396 - 400 vol.2
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    This paper analyzes the cutoff rate performance for space diversity in Rayleigh fading channels without channel state information (CSI). Selection combining (SC), maximal ratio combining (MRC) and equal gain combining (EGG) are considered as diversity combing techniques. For these schemes, the Chernoff factors are derived in a correlated Rayleigh fading channel without CSI. Some numerical results ... 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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  • Performance evaluation of a multi-rate CDMA system with orthogonal modulation over a multipath fading channel

    Publication Year: 1997, Page(s):632 - 636 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    This paper presents the performance analysis of a multiple data rate CDMA system with multiple spreading bandwidth under multipath fading channel. The analysis is based on three types of noncoherent receivers with and without amplitude and path delay estimations 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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  • Multi-code CDMA with variable sequence-sets

    Publication Year: 1997, Page(s):628 - 631 vol.2
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    To increase the spectrum efficiency in mobile communications, multi-code code-division multiple-access (MC-CDMA) systems have been proposed. An adaptive MC-CDMA scheme is discussed which allows one to support variable source data-rates by variation of the set of code-sequences assigned to each user. Especially in multimedia scenarios with different data-rates and different requirements on the tran... View full abstract»

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  • Dynamic mobility tracking for wireless personal communication networks

    Publication Year: 1997, Page(s):448 - 452 vol.2
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    A dynamic mobility tracking scheme is developed to minimize the cost of mobility tracking by optimally partitioning the service area into location registration (LR) areas on a per-user basis. This cost is affected by the mobility and call pattern of the individual subscriber, as well as the size and the orientation of the LR area. A more realistic mobility model is proposed in which we take not on... View full abstract»

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  • Design aspects and system evaluations of IS-95 based CDMA systems

    Publication Year: 1997, Page(s):381 - 385 vol.2
    Cited by:  Papers (8)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    The system performance of IS-95 based CDMA systems are studied in non-uniform and uniform traffic distributions in a uniform cell size. The three key elements in designing CDMA systems are pilot channel Ec/Io, forward traffic channel Eb/No and reverse traffic channel Eb/No. The CDMA system performance are evaluated in terms of capacity, soft handoff percentages, signal and interference power level... View full abstract»

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  • Potential of the GSM air interface to support CDMA operation

    Publication Year: 1997, Page(s):883 - 887 vol.2
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    An important issue in the development of third generation systems is the need for compatibility with the existing second generation systems. This paper considers the feasibility of supporting CDMA operation within the GSM air interface in order to provide UMTS capabilities. It produces performance estimates for two specific examples: joint detection CDMA channels, and multicarrier DS-CDMA channels... View full abstract»

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  • Interconnection of wireless cells a multicast-based approach

    Publication Year: 1997, Page(s):552 - 556 vol.2
    Cited by:  Papers (2)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (460 KB)

    This paper presents a solution to interconnect wireless cells to reach common LAN-dimensions. The protocol uses multicast to support fast handover in the presence of mobility in a local environment. The approach is strictly connectionless. A performance evaluation points out the benefits gained by using the multicast and estimates the drawbacks induced by the connectionless approach and by bufferi... View full abstract»

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  • A scheme for throughput maximization in a dual-class CDMA system

    Publication Year: 1997, Page(s):623 - 627 vol.2
    Cited by:  Papers (9)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (560 KB)

    The uplink of a CDMA system with two user classes is considered. One of the classes consists of delay intolerant users requiring support for a constant information bit rate R, while the other consists of delay tolerant users needing support for an information bit rate of at least R m. It is assumed that when not transmitting information, both classes maintain synchronization contact wit... View full abstract»

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  • Joint symbol, frame, and carrier synchronization for Eureka 147 DAB system

    Publication Year: 1997, Page(s):693 - 697 vol.2
    Cited by:  Papers (2)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    We present a joint symbol, frame, and carrier synchronization method for an OFDM signal in this paper. Symbol timing is determined first by detecting an abrupt phase change in the autocorrelation of the last quarter (e.g. Eureka 147 DAB) useful symbol and its cyclic extension in the guard interval. Frequency offset of fractional carrier spacing can be estimated from the phase angle of this autocor... View full abstract»

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  • Minimum duration outages in Markov channels

    Publication Year: 1997, Page(s):583 - 587 vol.2
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB)

    We present an analytical framework for the computation of the outage probability, the outage duration and the frequency of outage. A Markov description is assumed for the channel, which allows closed-form solutions and can effectively model many situations of interest. Outage events are defined as the channel being attenuated for at least a time duration τ (minimum duration outage). Also, exte... View full abstract»

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  • A novel tracking strategy for personal communication networks

    Publication Year: 1997, Page(s):443 - 447 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    A new scheme to partition and track mobile users, and its implementation based on cellular architecture is proposed. We use the cost analysis model to demonstrate feasibility of updating and searching costs to reduce the amount of resources when using wireless channels. Simulations are performed to compare performance of three schemes: always update, always search, and our new scheme 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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  • Applying list output Viterbi algorithms to a GSM-based mobile cellular radio system

    Publication Year: 1997, Page(s):878 - 882 vol.2
    Cited by:  Papers (1)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (420 KB)

    Digital mobile radio systems based on the pan-European standards GSM and DCS 1800 use concatenated coding schemes consisting of an inner error correcting convolutional code and an outer error detecting block code to ensure an appropriate performance. An improvement of this performance was achieved by applying list generating algorithms supplying a list of possible convolutional decoded sequences t... View full abstract»

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  • An efficient distributed channel management algorithm for cellular mobile networks

    Publication Year: 1997, Page(s):646 - 650 vol.2
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (636 KB)

    We propose a novel channel management algorithm, called distributed load balancing with selective borrowing (D-LBSB), for cellular mobile networks. As an underlying approach, we start with a fixed channel assignment scheme where each cell is initially allocated a set of local channels, each to be assigned on demand to a user in that cell. The novelty of our D-LBSB scheme lies in handling the hot c... View full abstract»

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  • Routing and multicast in multihop, mobile wireless networks

    Publication Year: 1997, Page(s):546 - 551 vol.2
    Cited by:  Papers (74)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (660 KB)

    In this paper we present a multicast protocol which builds upon a cluster based wireless network infrastructure. First, we introduce the network infrastructure which includes several innovative features such as: minimum change cluster formation; dynamic priority token access protocol, and distributed hierarchical routing. Then, for this infrastructure we propose a multicast protocol which is inspi... View full abstract»

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  • Hybrid ARQ for IP packet transmission

    Publication Year: 1997, Page(s):531 - 535 vol.2
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (444 KB)

    This paper proposes and analyses the performance of a hybrid selective repeat (SR)/multi copy (MC) automatic repeat request (ARQ) scheme to transmit fragmented Internet protocol (IP) packets. The ARQ scheme works in SR mode till the last IP packet fragment is transmitted. If a packet is negatively acknowledged after the last fragment is transmitted then the system goes in MC mode. In MC mode multi... View full abstract»

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  • Orthogonal multi-spreading factor forward link for coherent DS-CDMA mobile radio

    Publication Year: 1997, Page(s):618 - 622 vol.2
    Cited by:  Papers (16)  |  Patents (36)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    We present a method of generating orthogonal spreading codes with different spreading factors (SFs), which are called orthogonal multi-SF codes. The orthogonal multi-SF codes are applied to the forward link so that all users transmitting data at different rates are orthogonalized and a single RAKE combiner can be used at the mobile receiver. The generated orthogonal multi-SF codes have a tree stru... View full abstract»

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  • A dynamic wired-resource reservation scheme with a connection rerouting method on ATM-based PCN

    Publication Year: 1997, Page(s):738 - 745 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    We propose a connection rerouting method for fast inter-switch handoffs, and a dynamic resource reservation scheme based on the connection rerouting method, for the ATM-based personal communications network. The rerouting method reduces the delay in the connection rerouting by reserving VPI/VCIs for possible inter-switch handoff calls in advance. This paper categorizes the traffic carried in wired... View full abstract»

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  • Maximum likelihood timing synchronizers for sampled PSK burst TDMA systems

    Publication Year: 1997, Page(s):686 - 692 vol.2
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (544 KB)

    A new maximum-likelihood (ML) symbol timing estimator for sampled, coherent, burst time division multiple access (TDMA), phase shift keyed (PSK) systems is derived. The estimator uses a periodic bit pattern for acquisition. The sufficient statistic turns out to be the ratio of the even and odd sample sums which is easily implementable digitally with much lower complexity as compared to previously ... View full abstract»

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