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1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)

4-4 Sept. 1998

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  • IEEE Fifth International Symposium on Spread Spectrum Techniques and Applications [front matter]

    Publication Year: 1998, Page(s):0_2 - 0_12
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    Freely Available from IEEE
  • A frequency error resistant blind interference-mitigating CDMA detector

    Publication Year: 1998, Page(s):858 - 862 vol.3
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    This paper presents an enhanced version of the previously-proposed blind adaptive interference detector (BAID) for direct-sequence code division multiple access (DS-CDMA) transmission. Such a new detector, named extended complex BAID (EC-BAID), reveals resistance to a possible large frequency shift (e.g., Doppler shift) on interfering carriers, and features invariance to the phase error on the use... View full abstract»

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  • Performance comparison of DS-BPSK and DS-QPSK CDMA systems

    Publication Year: 1998, Page(s):802 - 805 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    QPSK (quadrature phase shift keying) has been known to be a bandwidth efficient modulation format. The performances of DS-BPSK (direct sequence binary phase shift keying) and DS-QPSK (direct sequence quadrature phase shift keying) modulation formats in a CDMA (code division multiple access) environment are compared in this study to see if this efficiency is preserved under the above conditions. Th... View full abstract»

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  • Multiuser detection analysis in DS-CDMA communication systems with Nakagami fading channels

    Publication Year: 1998, Page(s):932 - 935 vol.3
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    The multiuser detection (MUD) performance analysis in a synchronous direct sequence code division multiple access (DS-CDMA) system using decorrelating and decision feedback (DFB) receivers, including single path Nakagami fading channel is presented. The lower bounds of the receivers bit error probability (BER) are derived. The analytical and numerical results show that the DFB receiver performs be... View full abstract»

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  • Coding of sampled human motion for the IS-95 standard

    Publication Year: 1998, Page(s):748 - 751 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (444 KB)

    Wireless, untethered or unencumbered sampling of human motion is a much sought after goal, yet this type of information represents an unfamiliar class of data compared to the speech and video counterparts. This paper reports on the applicability of traditional waveform coding techniques such as dead reckoning and DPCM to specifically compress human motion data. The implicit processing gain achieve... View full abstract»

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  • Statistical techniques for blind detection & discrimination of m-sequence codes in DS/SS systems

    Publication Year: 1998, Page(s):853 - 857 vol.3
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    Advances in modern DSP techniques provide a means for intercepting smart covert signal emitters by taking account of the structural properties of their waveform and/or spectra. Previous research has shown that higher-order statistical processing can detect and characterise direct-sequence spread-spectrum signals. Triple correlation analysis is able to detect m-sequence chip codes and also estimate... View full abstract»

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  • Design of Reed-Solomon frequency-time hopping sequences

    Publication Year: 1998, Page(s):982 - 986 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (460 KB)

    This article considers a hybrid TDMA/FDMA with and without CDMA multiple access system where joint frequency and time hopping sequences are employed to improve the system performance. The system is a proposal for a UMTS radio access system (named FRAMES Multiple Access (FMA)) and is based on wideband TDMA with and without spreading (CDMA component). The users are orthogonally separated into time s... View full abstract»

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  • Information capacity of the space division multiple access mobile communication system

    Publication Year: 1998, Page(s):946 - 950 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    An expression for the Shannon capacity lower bound of the space division multiple access (SDMA) mobile communication channel with interference is shown. The bound is tightly approaching the Shannon capacity of the orthogonal SDMA system over Gaussian channels with no interference. The information capacity of the SDMA system with adaptive MMSE receivers is presented as well. The SDMA system with MM... View full abstract»

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  • On the maximum uplink capacity per km2 of CDMA systems

    Publication Year: 1998, Page(s):798 - 801 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    In the recent literature, many works have concentrated on system performance of CDMA networks. In particular, numerous analytical derivations of CDMA cell capacity have been carried out. However, to the authors' knowledge, the issue of capacity per km2 has never been addressed directly nor extensively in the past. In the present work, a thorough analysis of coverage and capacity issues ... View full abstract»

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  • Multistage detector for adaptive separation of QAM-modulated multiuser CDMA signals

    Publication Year: 1998, Page(s):927 - 931 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    Code division multiple access (CDMA) proves to be an attractive method for multiuser communication due to its potential capacity increase and anti-multipath fading capability. However, its performance is limited by the existence of multiple access interference energy (MAI), which results in the so called near-far problem. To reduce the MAI effect, different structures for multiuser separators have... View full abstract»

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  • Minimax algorithm application in ECF and ECUI design

    Publication Year: 1998, Page(s):999 - 1002 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    A new approach is proposed to envelope constrained filter (ECF) design. The new approach utilizes the minimax algorithms, originally developed for sidelobe suppression in radar applications. The new approach has been compared to the conventional approach, which utilizes the tools of nonlinear programming. The comparative analysis shows that the new approach promises a better performance in the non... View full abstract»

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  • A color image communication using YIQ signals by spread spectrum techniques

    Publication Year: 1998, Page(s):743 - 747 vol.3
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    In spread spectrum systems, many pseudo-random numbers with good properties are required. In such systems, linear feedback shift register (LFSR) sequences have been often used. We use Chebyshev bit sequences as spread spectrum sequences, generated by one-dimensional nonlinear ergodic chaotic maps primarily because they are sequences of i.i.d. (independent and identically distributed) binary random... View full abstract»

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  • Performance evaluation of spread-spectrum code acquisition system using four-state Markov process

    Publication Year: 1998, Page(s):848 - 852 vol.3
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    A direct sequence serial search acquisition scheme based on the assumption that there are two adjacent in-phase states (H1 cell) in the code position uncertainty region, on which the received pseudorandom noise (PN) code and the local despreading PN code signal is coarsely aligned, is presented. To utilize both cells, the test statistic is composed of the observation on the couple of ad... View full abstract»

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  • The role of frequency hopping in today's digital communications

    Publication Year: 1998, Page(s):978 - 981 vol.3
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    We investigate the capacity of an OOK FH CDMA channel. We assume random FH codes and that the i-th receiver is only interested in the message transmitted by the i-th transmitter. The degradation of the AWGN and non-selective Rayleigh fading environments on the FH system are also investigated. We then give an algebraic construction of a new family of FH codes. The construction is based on the prope... View full abstract»

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  • Optimum multi-user signal detector in SSMA communication systems based on neural networks

    Publication Year: 1998, Page(s):868 - 872 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (420 KB)

    This paper is motivated by the fact that, in a multi-user CDMA system, the conventional receiver suffers severe performance degradation as the relative powers of the interfering signals becomes large (i.e., “near-far problem”). Furthermore, in many cases the optimum multi-user receiver, which alleviates the near-far problem, is too complex to be of practical use. By viewing this optimu... View full abstract»

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  • Performance analysis of the enhanced PN spread spectrum system in the presence of jamming by modulated retransmitted signal

    Publication Year: 1998, Page(s):809 - 811 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    An anti-jamming direct sequence spread spectrum system is considered. We believe that an enemy can detect phase shifts from chip by chip and create a “retransmitted” interference with additional modulation. To prevent this attack we propose another version of pseudonoise spread spectrum system which is based on combined phase shift-keyed and frequency shift-keyed modulation. The perfor... View full abstract»

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  • Optimum single-user detection for DS/CDMA systems achieving complete MAI cancellation

    Publication Year: 1998, Page(s):941 - 945 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    Conventional matched-filter detection (MFD) in a DS/CDMA system is sub-optimal when the channel noise is dominated by multiple access interference (MAI). MAI is a limiting factor to the bit error rate performance. Multi-user detector schemes have been proposed to combat MAI but these schemes have a high degree of complexity. The optimum single-user detector (OSD) considerably reduces the complexit... View full abstract»

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  • Ambiguity characterization of arbitrary antenna array: type II ambiguity

    Publication Year: 1998, Page(s):955 - 958 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    In this paper we propose an approach to type II ambiguity analysis of arbitrary volume antenna array. This approach is interesting especially from the point of in designing of volume antenna arrays for mobile communications. We define and propose a type II ambiguity function and show that the proposed function is very effective tool for type II ambiguity characterization of volume antenna arrays View full abstract»

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  • CDMA sectorized distributed antenna system

    Publication Year: 1998, Page(s):792 - 797 vol.3
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (656 KB)

    The objective of this study is to utilize antennas in novel ways so as to achieve performance benefits at the system level in future wireless networks. Despite possessing many appealing features, CDMA distributed antenna (DA) systems suffer from low capacity per antenna element (AE) as a result of the multiple access interference (MAI) accumulated in the common feeder. To overcome this capacity li... View full abstract»

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  • Multipath-diversity performance of direct-sequence CDMA using combined M-ary signalling

    Publication Year: 1998, Page(s):781 - 785 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    A combined binary PPM/orthogonal modulation is used in cellular CDMA reverse links in which the multipath-diversity performance for Rayleigh-fading channels is evaluated and compared. As for diversity techniques, equal gain combining (EGC), selection combining (SC), and its generalization, second or third order SC (SC2, SC3), are considered for noncoherent reception. Theoretical analyses show that... View full abstract»

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  • An multiple access interference (MAI) cancellation detector at the mobile terminal in CDMA systems

    Publication Year: 1998, Page(s):922 - 926 vol.3
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB)

    Interference cancellation has become a hot topic in CDMA systems. Most of application are used in the base station receiver due to the complexity. Less work has been done in the mobile terminal. We propose a MAI cancellation detector at the mobile station receiver. The detector does not require an estimation of the interferers' data bit. If the channel estimation subtracted from pilot signal is pe... View full abstract»

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  • A novel transmission diversity system in TDD-CDMA

    Publication Year: 1998, Page(s):771 - 775 vol.3
    Cited by:  Papers (23)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    This paper presents a novel transmission diversity scheme for code division multiple access system. Conventional diversity receivers in mobile stations require space and complicated circuits, however, the proposed diversity schemes presents significant diversity effect without any diversity equipment at the mobile station. It is possible to use the transmitter diversity at the base station by usin... View full abstract»

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  • Signal design and in-orbit performance of the new microwave satellite tracking system PRARE

    Publication Year: 1998, Page(s):724 - 728 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (416 KB)

    The new two-way microwave satellite tracking system PRARE has been in continuous operation on-board ERS-2 since May 1, 1995. With the assistance of a network of mobile, autonomous PRARE ground stations, the PRARE space segment generates on a global basis two-way pseudonoise-coded range and carrier shifted Doppler measurements at the sub-dm resp. sub-mm/s level of accuracy. These data are primarily... View full abstract»

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  • Highly integrated chips for commercial CDMA-based satcom applications: some case studies

    Publication Year: 1998, Page(s):912 - 916 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (708 KB)

    A number of commercial CDMA-based satellite communication applications are discussed. They were realized using highly integrated digital baseband chips. The provision of on-chip hardware for S-CDMA (synchronous CDMA) transmission and demodulation allows for a significant capacity increase. The integration of on-chip microcontrollers reduces power consumption and board size. For small to volumes, A... View full abstract»

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  • Decision-directed PLL used for coherent optical pulse CDMA systems in the presence of multiuser interference, laser phase noise and shot noise

    Publication Year: 1998, Page(s):762 - 766 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (580 KB)

    A decision-directed phase-locked loop (PLL) is proposed for use in coherent optical pulse CDMA systems via coherent correlation demodulation. The effect of multiuser interference, laser phase noise and shot noise on the PLL performance is evaluated based on a nonlinear model (the Fokker-Planck method) since a linear analysis yields large deviations between the analytical results and actual perform... View full abstract»

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