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Proceedings 2001 IEEE Information Theory Workshop (Cat. No.01EX494)

2-7 Sept. 2001

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  • Proceedings 2001 IEEE Information Theory Workshop [front matter]

    Publication Year: 2001, Page(s):i - vii
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    Freely Available from IEEE
  • Proceedings 2001 IEEE Information Theory Workshop (Cat. No.01EX494)

    Publication Year: 2001
    Request permission for commercial reuse | PDF file iconPDF (341 KB)
    Freely Available from IEEE
  • New low-complexity turbo-like codes

    Publication Year: 2001, Page(s):70 - 72
    Cited by:  Papers (17)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (287 KB) | HTML iconHTML

    We discuss the design of new low-complexity turbo-like codes based on a multiple parallel concatenation of 4-state and 2-state constituent codes. The new code designs take advantage of the big-numerator/little-denominator principle along with specially designed interleavers to outperform previously designed turbo codes over the entire range of signal-to-noise ratios. Puncturing at the encoder is u... View full abstract»

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  • Capacities of time-varying multiple-access channels with side information

    Publication Year: 2001
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (50 KB)

    Summary form only given. We address the capacity problem for a class of time-varying multiple-access channels (TVMAC), when the underlying channel state evolves in time according to a probability law which is known to the transmitters and the receiver. Additionally, the transmitters and the receiver have access to varying degrees of channel state information (CSI) concerning the condition of the c... View full abstract»

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  • Author index

    Publication Year: 2001, Page(s): 0_1
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  • The effect of distortion on the MDL model

    Publication Year: 2001, Page(s):156 - 157
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB) | HTML iconHTML

    We investigate the consequences of lossy compression, i.e., description with distortion, on the model selection of the minimum description length (MDL) criterion. Our basic observation is that for a finite data sequence and sufficiently large distortion, a two-stage universal lossy encoder tends to under-estimate the model order of the source. We demonstrate this property by examining the behavior... View full abstract»

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  • Capacity considerations for trellis code multiple access systems

    Publication Year: 2001, Page(s):153 - 155
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB) | HTML iconHTML

    Trellis code multiple access (TCMA) is a narrow-band multiple access scheme. There is no bandwidth expansion, so K users are using the same bandwidth as one single user. The load (the number of bits per channel use) of the system is therefore much higher than the load in, for example, conventional CDMA systems. It is shown here that the maximum number of users in a TCMA system is usually modest. T... View full abstract»

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  • Joint decoding of serially concatenated coded CDMA: iterative schedule study

    Publication Year: 2001, Page(s):58 - 60
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB) | HTML iconHTML

    Joint iterative decoding of forward error control (FEC) encoded code-division multiple-access (CDMA) systems is studied. Serially concatenated convolutional codes are used as FEC codes. We apply iterative decoding to this system and study the effect of component decoders and different decoding partition schemes via a variance transfer analysis. It is shown that distinct partition schemes result in... View full abstract»

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  • Achievable rate of MIMO channels with data-aided channel estimation

    Publication Year: 2001, Page(s):150 - 152
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB) | HTML iconHTML

    The achievable rate of a coherent coded modulation (CM) digital communication system with data-aided channel estimation and a discrete, equiprobable symbol alphabet is derived under the assumption that the system operates on a flat fading MIMO channel and uses an interleaver to combat the bursty nature of the channel. It is shown that linear minimum mean square error (LMMSE) channel estimation dir... View full abstract»

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  • Constructions of specific permutation codes for multi-user communication

    Publication Year: 2001, Page(s):79 - 81
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB) | HTML iconHTML

    Regular constructions for specific permutation codes used in a multiple-access OR channel where the inputs originate from a fast frequency hopping/multiple frequency shift keying modulation are presented for 3 situations : (1) each sender is either active or passive; (2) the jammer is allowed to corrupt a certain number of transmitted frequencies; and (3) the sender transmit one of a certain numbe... View full abstract»

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  • Design of space-time turbo TCM on fading channels

    Publication Year: 2001, Page(s):123 - 125
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB) | HTML iconHTML

    Novel code design criteria for space-time codes on slow Rayleigh fading channels are presented. It is shown that the code performance is dominated by the minimum rank r and the minimum determinant of the codeword distance matrix when the product of the minimum rank r and the number of receive antennas nR is less than 4. However, when r·nR is greater than or equal to 4,... View full abstract»

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  • Analog decoding of product codes

    Publication Year: 2001, Page(s):131 - 133
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB) | HTML iconHTML

    A design approach is presented for soft-decision decoding of block product codes ("block turbo codes") using analog computation with MOS devices. Application of analog decoding to large code sizes is also considered with the introduction of serial analog interfaces and pipeline schedules View full abstract»

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  • Asymptotic analysis of widely linear MMSE multiuser detection-complex vs real modulation

    Publication Year: 2001, Page(s):55 - 57
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB) | HTML iconHTML

    We give the asymptotic signal-to-interference ratio for the so-called widely linear minimum mean-squared error multiuser receiver for transmission of multiple users to a common receiver with DS-CDMA. Observing that widely linear multiuser detection virtually doubles the spreading factor, we show that transmission with real-valued channel symbols can lead to a higher spectral efficiency than with c... View full abstract»

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  • An upper bound on the capacity of channels with memory and constraint input

    Publication Year: 2001, Page(s):147 - 149
    Cited by:  Papers (27)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB) | HTML iconHTML

    A method for computing upper bounds on capacity for a class of time-invariant indecomposable finite state channels is presented. It extends a result for finite-input memoryless channels. Numerical results are provided for selected channels having memory and constraint (binary) input View full abstract»

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  • Concatenated tree codes and related schemes

    Publication Year: 2001, Page(s):76 - 78
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB) | HTML iconHTML

    We report the progress in concatenated tree (CT) codes and related schemes, including low rate codes for CDMA applications and bandwidth efficient coded modulation schemes. It is shown that CT codes provide efficient solutions for various situations. Near capacity performances (within about 0.5 dB) can be achieved at significantly reduced decoding costs View full abstract»

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  • Fading channels in the power limited regime

    Publication Year: 2001, Page(s):99 - 100
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB) | HTML iconHTML

    The tradeoff of spectral efficiency vs. energy-per information bit (normalized to the noise level Eb/N0) is the key measure of the capacity of channels in the power-limited regime. This paper finds the fundamental bandwidth-power tradeoff of a general class of channels in the wideband regime in which the spectral efficiency is small but nonzero View full abstract»

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  • Differential turbo space-time coding

    Publication Year: 2001, Page(s):120 - 122
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB) | HTML iconHTML

    Serial concatenation of standard convolutional or block codes with differential space-time modulation is considered for flat fading multiple antenna channels. Extrinsic information transfer is used to predict thresholds for various outer codes. Using the differential structure of the inner code near coherent performance is obtained without the use of training symbols View full abstract»

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  • The turbo principle in joint source channel decoding of variable length codes

    Publication Year: 2001, Page(s):33 - 35
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB) | HTML iconHTML

    The turbo principle has been widely applied to various detection/decoding problems in recent years. Here we show how the general idea can be extended to a communication scheme where a variable length code is used for data compression followed by a channel code to protect the data against channel errors. Iterations are performed between the channel decoder and the decoder for the variable length so... View full abstract»

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  • Analog decoders for high rate convolutional codes

    Publication Year: 2001, Page(s):128 - 130
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB) | HTML iconHTML

    Recently, several VLSI implementations of analog decoders have been reported for rate 1/2 tailbiting convolutional codes. The main advantages of analog decoders are much higher decoding speed, smaller chip size and lower power consumption when compared to an equivalent digital decoder. Since many high speed applications require code rates well above 1/2 we focus on high rate tailbiting convolution... View full abstract»

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  • Random CDMA in the multiple cell uplink environment: the effect of fading on various receivers

    Publication Year: 2001, Page(s):42 - 44
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB) | HTML iconHTML

    A simple multi-cell Rayleigh fading uplink communication model is suggested and analyzed for optimally coded randomly spread DS-CDMA with multiuser detection. The model adheres to Wyner's (1994) infinite linear cell-array setting, according to which only adjacent-cell interference is present, and characterized by a single parameter 0⩽α⩽1. The discussion is confined to asymptotic anal... View full abstract»

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  • Low-dimensional spreading matrices for multiuser space-time modulation

    Publication Year: 2001, Page(s):51 - 53
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB) | HTML iconHTML

    In a previous paper we proposed a multiuser space-time modulation scheme that leverages single-user space-time constellations and guarantees both, a full diversity order, as well as an asymptotic (high SNR) single-user like performance for every user. This is achieved by multiplying each user's space-time information matrix symbol by a low-dimensional "spreading matrix." For instance, for NT<... View full abstract»

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  • A random matrix model for the antenna array channel with decaying power delay profile

    Publication Year: 2001, Page(s):144 - 146
    Cited by:  Papers (1)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB) | HTML iconHTML

    The random matrix model for multipath propagation on the antenna array channel is generalised to decaying power delay profiles. Results are given in terms of Stieltjes transforms of the eigenvalue distributions of the channel's space-time covariance matrix View full abstract»

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  • On the design of bit-interleaved turbo-coded modulation

    Publication Year: 2001, Page(s):73 - 75
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB) | HTML iconHTML

    Bit-interleaved turbo-coded modulations (BITCM) have been shown to achieve bit error rate performance very close to the capacity limit over both additive white Gaussian noise (AWGN) channels and Rayleigh fading channels. So far, most studies have been done on BITCM systems designed using rectangular QAM signal sets. In this paper, we address the problem of finding some constellations that would be... View full abstract»

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  • "Codes" on images and iterative phase unwrapping

    Publication Year: 2001, Page(s):9 - 11
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB) | HTML iconHTML

    Many imaging techniques, including magnetic resonance imaging and interferometric synthetic aperture radar, produce "phase-wrapped" images. In a phase-wrapped image, the original image values are measured modulus a known wavelength, A. The goal of phase unwrapping is to produce an estimate of the original image using an a priori preference for smooth images. We formulate phase unwrapping as the pr... View full abstract»

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  • Direct sum construction of DC-free adder channel codes

    Publication Year: 2001, Page(s):96 - 98
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB) | HTML iconHTML

    The design of uniquely decodable DC-free multi-user coding schemes with good rate sums for the multiple access adder channel is described in this paper. It is shown that by using the direct sum construction on short multi-user codes, it is possible to devise longer DC-free multi-user coding schemes with rate sums which increase quite rapidly at each iteration of the construction. Asymptotically, t... View full abstract»

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