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Global Telecommunications Conference, 1998. GLOBECOM 1998. The Bridge to Global Integration. IEEE

Date 8-12 Nov. 1998

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  • IEEE Globecom 1998 [front matter]

    Publication Year: 1998 , Page(s): i - xii
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  • An emulator for testing the performance of framed access schemes

    Publication Year: 1998 , Page(s): 3777 - 3782
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  • Author index

    Publication Year: 1998 , Page(s): xiii - xxi
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  • A new flexible multiuser detection scheme for DS CDMA systems

    Publication Year: 1998 , Page(s): 3560 - 3565 vol.6
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (296 KB)  

    We consider a synchronous code division multiple access (CDMA) system where all users share an additive white Gaussian noise channel. For this multiuser communication system a new so-called hybrid multiuser detection scheme based on a favourable link of multistage multiuser detection algorithms and maximum likelihood detection is presented. It is shown that this scheme yields a profitable tradeoff... View full abstract»

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  • Carrier recovery scheme for on-board demodulation suited to low E b/N0

    Publication Year: 1998 , Page(s): 3432 - 3436 vol.6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (232 KB)  

    In this paper we describe and analyse new feedforward synchronization algorithms suited to on-board digital implementation. Both algorithms studied here (for phase and frequency recovery) have the particularity to perform all calculations in polar coordinates and so to reduce complexity of implementation. A phase estimator operating at very low SNR with no frequency offset is defined. Its performa... View full abstract»

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  • Emergency communication services: demand, development and system implementation in China

    Publication Year: 1998 , Page(s): 3176 - 3180 vol.6
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (248 KB)  

    The demands for emergency communication services have grown very fast in the past few years. The history and characteristics of emergency communication techniques are reviewed. By concentrating on public security applications, several emergency communication systems have been successfully developed based upon the concept and architecture of the intelligent network. The implementation and functions... View full abstract»

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  • Channel decoding of block codes with a priori information

    Publication Year: 1998 , Page(s): 3536 - 3541 vol.6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (480 KB)  

    We propose a complete transmission system for still images. This system comprises a VQ source encoder with a compression rate of 9 and the data is encoded using a BCH block code and mapped on a 16-QAM constellation. Two BCH codes are considered: BCH(29,24,3) and BCH(54,48,3). The parameters of the code book and channel encoder have been optimized for 16-QAM. We use a new joint source-channel decod... View full abstract»

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  • Analysis of performance measures of forward CDMA link with non-linear devices in the signal path

    Publication Year: 1998 , Page(s): 3302 - 3307 vol.6
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    We investigate the performance of the forward link in IS-95 CDMA systems in the presence of non-linear devices in the signal path. One possible measure of this performance is the Walsh power ratio (WPR) a new concept developed at Qualcomm Inc. The importance of the WPR as a system performance measure is signified by the fact that the symbol error rate (SER) due to non-linearities, is a function of... View full abstract»

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  • Downlink signal to interference ratio calculation for PACS-UB systems

    Publication Year: 1998 , Page(s): 3675 - 3679 vol.6
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    The Personal Access Communications System-Unlicensed B (PACS-UB) is a standard intended to operate in the (1920-1930 MHz) band allocated for Unlicensed Personal Communication Services (UPCS) in the US. The access of portables in PACS-UB is carried out based on measurements. This paper presents the analytical derivation of the downlink signal to interference ratio (SIR) probability density function... View full abstract»

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  • Coding for multi-user detection in interference channel

    Publication Year: 1998 , Page(s): 3596 - 3601 vol.6
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    A uniquely decodable code is derived for multiple-access in a two-user interference channel, which is defined as a channel with complex input, output and arbitrary phase difference between the two users. The uniquely decodability is achieved by designing a trellis-coded modulation (TCM) pair, that permits the Viterbi decoder to decompose the composite received signal into the two constituent signa... View full abstract»

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  • RAM-search algorithms for nonlinear ISI cancellation in magnetic recording

    Publication Year: 1998 , Page(s): 3368 - 3373 vol.6
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (304 KB)  

    We discuss two algorithms for mitigating the deleterious effects of nonlinear intersymbol interference (ISI) in PR4- and EPR4-equalized magnetic recording channels. We call them RAM-search algorithms as they borrow the idea of employing a RAM (random access memory) from the RAM-DFE, and because they involve a search. The algorithms have been devised to circumvent the error propagation problem that... View full abstract»

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  • Multi-user performance of CDMA in the presence of phase noise

    Publication Year: 1998 , Page(s): 3314 - 3319 vol.6
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (296 KB)  

    Phase noise can be the major source of performance degradation in low cost low bit-rate digital systems operating in the millimeter wavelength band. The use of CDMA with a differential modulation at the chip level will permit an improvement in system performance and a simpler demodulation. However, the enhancement of CDMA multi-user interference arising from the differential receiver has to be con... View full abstract»

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  • PS-CDMA: spreading signals for CDMA designed in the frequency domain using perfect sequences

    Publication Year: 1998 , Page(s): 3420 - 3425 vol.6
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    In this paper are described some new approaches to the definition of CDMA spreading functions. The simplest method increases the code space up to 50%. The most sophisticated one performs a very strong rejection to the delayed replicas of the interfering signals. Several advantages have also been found in the FFT implementation of PS-CDMA transmitters and receivers, the elimination of the analog ma... View full abstract»

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  • Hybrid Kalman/LMS decision feedback equalization strategy for terrestrial HDTV channels

    Publication Year: 1998 , Page(s): 3497 - 3502 vol.6
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    An LMS decision feedback equalizer (DFE) with the Kalman algorithm used in training period is proposed for terrestrial HDTV broadcasting. The utilization of Kalman's algorithm is intended solely for fast startup and optimality of estimating the equalization coefficients. The LMS algorithm is employed in a decision-directed mode primarily due to its simplicity, robustness and good tracking behavior... View full abstract»

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  • Different ramp up signals

    Publication Year: 1998 , Page(s): 3699 - 3703 vol.6
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    DECT is an ETSI standard used world-wide for home, business and public applications. One of the principal characteristics for DECT systems is interworking. In order to verify that, the receivers have been tested emulating the ramp up signals transmitted by several commercially available handsets. The testing has been done in an experimental set-up making use of a “ad hoc” board connect... View full abstract»

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  • Reducing the fading rate with antenna arrays

    Publication Year: 1998 , Page(s): 3187 - 3192 vol.6
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    The Rayleigh like fading of the mobile channel limits the channel capacity. Reduction of this fading at the mobile is possible by Doppler frequency compensation on fixed directional beams formed by an array of antennas. The proposed technique uses a partitioning of the angular domain that generates equal contributions to Doppler shifts. Such equal Doppler contributions can be desirable in antenna ... View full abstract»

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  • Throughput evaluation of a satellite switched CDMA (SS/CDMA) demand assignment system

    Publication Year: 1998 , Page(s): 3632 - 3638 vol.6
    Cited by:  Patents (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (428 KB)  

    This paper presents throughput evaluation of a satellite switched code division multiple access (SS/CDMA) system which operates under demand assignment control. The SS/CDMA provides both multiple access and switching to a geostationary multibeam satellite. Multiple access is resolved by space, frequency and code division. Space division is introduced by the multibeam antennae that provide frequenc... View full abstract»

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  • Computation of minimum complexity for near optimal synchronous CDMA multiuser detection

    Publication Year: 1998 , Page(s): 3554 - 3559 vol.6
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    In this paper, we show how to compute the minimum complexity (in terms of the number of paths kept) for near optimal M-algorithm multiuser detection. Several proven properties of the vector Euclidean distance (VED) are utilised to give an efficient algorithm for computing the minimum VED leading to a value for the minimum required number of paths to be kept for a given number of users. The analyti... View full abstract»

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  • Error probability performance of OFDM-ADSL systems

    Publication Year: 1998 , Page(s): 3326 - 3331 vol.6
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    This paper presents an error probability analysis for the orthogonal frequency division multiplexing (OFDM)-asymmetrical digital subscriber loop (ADSL) system. By adopting a discrete form of the impulse response of the ADSL and by establishing statistical models for various transmission impairments, such as intracarrier interference (ICI), and impulse noise (IN), a closed-form expression for the e... View full abstract»

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  • Matched codes for ISI channels

    Publication Year: 1998 , Page(s): 3530 - 3535 vol.6
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (288 KB)  

    The performance of a bandlimited communication system in the presence of additive white Gaussian noise depends on the minimum Euclidean distance, dmin, between different signal sequences. To further increase dmin, convolutional or trellis, coding could be used. Search results indicate that the encoder with the best free distance does not always give the best coded distance wh... View full abstract»

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  • General method for computing the power spectrum density of irreducible periodic Markov chains

    Publication Year: 1998 , Page(s): 3320 - 3325 vol.6
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (312 KB)  

    Many signals occurring in data communications can be described by Markov models. The formula for the power spectrum density (PSD) of a signal driven by an irreducible aperiodic Markov chain with uniformly spaced transitions was first published in 1961 by Titsworth and Welch and in 1973 by Lindsey and Marvin. There are, however, a number of systems in which the aperiodicity assumption is not correc... View full abstract»

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  • Turbo coding for discrete multitone transmission systems

    Publication Year: 1998 , Page(s): 3256 - 3260 vol.6
    Cited by:  Papers (6)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (284 KB)  

    This paper provides a framework for combining turbo coding with discrete multitone transmission. The combination exploits the superior performance of turbo codes on additive white Gaussian noise channels. A single turbo code is used to modulate all subchannels in the multitone system. Thus, the turbo code is independent of the multitone system and channel parameters. The system yields coding gains... View full abstract»

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  • Comparison of TDMA versus CDMA for packet transmission schemes in circuit-mode

    Publication Year: 1998 , Page(s): 3414 - 3419 vol.6
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (316 KB)  

    We compare the performance of a TDMA multiple access scheme with a CDMA multiple access scheme when both are used for packet transmission in the circuit-mode. First we consider a more general model of slotted Aloha protocol on a channel with capture effect. Both TDMA and CDMA are shown to be special cases of this model. There are M<∞ users each with an infinite buffer. If in a slot, i pac... View full abstract»

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  • An improved analysis of outage probability with correlated co-channel interferers

    Publication Year: 1998 , Page(s): 3710 - 3715 vol.6
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (336 KB)  

    The problem of computing the outage probability in mobile radio systems is investigated in the presence of log-normal shadowing. A relevant feature is that the proposed analysis assumes a general correlation for and pair of links. Various approaches are considered to compute the joint statistic of the user signal strength and the sum of interferers, namely: the Schwartz and Yeh's (1982) method, th... View full abstract»

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  • A fast algorithm for choosing frame synchronization unique word

    Publication Year: 1998 , Page(s): 3437 - 3442 vol.6
    Cited by:  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (276 KB)  

    The frame synchronization unique word (UW) is very important for burst data communication systems. Commonly used UWs such as M-sequences are not optimized for specific system environments. This paper gives both the upper and lower boundaries of mis-detection probability of frame synchronization. Based on these boundaries, an effective algorithm to find the optimal frame synchronization UWs for a g... View full abstract»

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