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Information Theory Workshop, 2001. Proceedings. 2001 IEEE

Date 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
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    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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  • Author index

    Publication Year: 2001, Page(s): 0_1
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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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  • Dense multiple antenna systems

    Publication Year: 2001, Page(s):108 - 109
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB) | HTML iconHTML

    We consider multiple antenna systems in which a large number of antennas occupy a given physical volume. In this regime the assumptions of the standard models of multiple antennas systems become questionable. We show that for such spatially dense multiple antenna systems one should expect the behavior of the capacity to be qualitatively different than what the standard multiple antenna models pred... 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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  • 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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  • The turbo principle in joint source channel decoding of variable length codes

    Publication Year: 2001, Page(s):33 - 35
    Cited by:  Papers (15)
    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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  • Constrained coding and soft iterative decoding

    Publication Year: 2001, Page(s):18 - 20
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB) | HTML iconHTML

    Constrained coding and error-control coding (ECC) are considered in a combined framework. In the context of soft iterative decoding, this allows the ECC decoder (e.g., for a turbo or LDPC code) to gain direct access to the probabilities from the channel decoder. In addition, a soft decoder for the constraint can be introduced to yield additional coding gain. Practical methods for combining the con... 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 (35 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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  • Some results on channel estimation and detection for space-time OFDM systems

    Publication Year: 2001, Page(s):116 - 118
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB) | HTML iconHTML

    We present results on multipath channel estimation and detection for space-time coded systems used in conjunction with orthogonal frequency-division multiplexing (OFDM). An expectation-maximization (EM) based algorithm is introduced and is shown to be more robust to multipath channel delay profile variations and can be implemented more efficiently compared to a recently proposed alternative algori... View full abstract»

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  • Three directional spectral null constraints for two-dimensional storage devices

    Publication Year: 2001, Page(s):93 - 95
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB) | HTML iconHTML

    Three-dimensional spectral null constraints for two dimensional storage devices are studied. These constraints may be useful when we use circular pits to store information on physical devices View full abstract»

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  • Impact of multiple access on uplink scheduling

    Publication Year: 2001, Page(s):48 - 50
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB) | HTML iconHTML

    We consider uplink scheduling for bursty traffic. We characterize the achievable rate region for Gaussian multiple access in terms of minimum required powers, with a constraint on average transmission delay for all users. We show that delay and rate constrained, power minimizing schemes perform scheduling accompanied with power control. Further, for the class of randomized stationary schedulers, i... View full abstract»

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  • Performance of iterative multiuser decision-feedback receivers

    Publication Year: 2001, Page(s):30 - 32
    Cited by:  Papers (3)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB) | HTML iconHTML

    We compare the performance of iterative multi-user successive and parallel decision feedback detectors (DFDs) for code-division multiple access (CDMA). An adaptive successive-DFD (S-DFD) is first presented, which requires only a training sequence and associated timing to estimate all filter coefficients. Simulation results show that with limited training, the adaptive S-DFD performs significantly ... View full abstract»

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  • The advantages of non-binary turbo codes

    Publication Year: 2001, Page(s):61 - 63
    Cited by:  Papers (59)  |  Patents (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB) | HTML iconHTML

    Non-binary turbo codes are built from recursive systematic convolutional (RSC) component codes with m inputs (m⩾2). This construction offers better performance than classical binary turbo codes, especially at very low BER and high coding rate. Some examples with rate 2/3 are given on 8-state and 16-state duo-binary turbo code associated with QPSK and 8-PSK modulation View full abstract»

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  • Transient and convergence properties of the BCJR decoder via a linear system model

    Publication Year: 2001, Page(s):135 - 137
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB) | HTML iconHTML

    The BCJR algorithm consists of two linear recursions whose joint transient response define the algorithm's response to errors. The transient behavior is described and some implications are discussed for sliding block decoder storage, recovery from incorrect starts, and good code design View full abstract»

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  • A class of systematic t/B-error correcting codes for semiconductor memory systems

    Publication Year: 2001, Page(s):85 - 86
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB) | HTML iconHTML

    This paper proposes a class of systematic codes called single t/B-error correcting - single b-bit byte error correcting - single b-bit block error detecting (StB/EC-SbEC-SBED) codes for high speed semiconductor memory systems. The proposed codes correct multiple random t-bit errors occurring within a chip and b-bit byte errors caused by sub-array data faults while ... View full abstract»

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  • Information capacity of a multipath mobile communication channel with large number of receiving antennas

    Publication Year: 2001, Page(s):104 - 106
    Cited by:  Papers (3)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB) | HTML iconHTML

    The expression for stationary channel information capacity of a mobile communication channel with a large number of receiving antennas in the presence of multipath signal propagation is shown. It has been shown that the capacity is approaching information capacity of the orthogonal Gaussian channel with no interference. The system with adaptive linear MMSE receivers and adaptive interference cance... View full abstract»

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  • Robust space-time codes for time-selective fading

    Publication Year: 2001, Page(s):112 - 114
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB) | HTML iconHTML

    We consider the design of robust codes that exploit both space and time diversity, using bit-interleaved coded modulation. Under quasi-static fading conditions, codes constructed in this way achieve full diversity and perform close to the best space-time trellis codes of comparable complexity. Under fast-fading conditions, these same codes achieve higher diversity than previously known codes of th... View full abstract»

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  • On interference cancellation and iterative techniques

    Publication Year: 2001, Page(s):39 - 41
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB) | HTML iconHTML

    Recent research activities in the area of mobile radio communications have moved to third generation (3G) cellular systems to achieve higher quality with variable transmission rate of multimedia information. In this paper, an overview is presented of various interference cancellation and iterative detection techniques that are believed to be suitable for 3G wireless communications systems. Key con... View full abstract»

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  • Maximum generating rate of the variable-length nonuniform random number

    Publication Year: 2001, Page(s):141 - 143
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB) | HTML iconHTML

    We investigate the maximum generating rate of the variable-length nonuniform i.i.d. random number. Our results are generalizations of Han's results (see IEEE Trans. Inform. Theory, vol.46, p.2108-16, Sept. 2000) on the variable-length intrinsic randomness View full abstract»

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  • Regular low-density parity-check codes from combinatorial designs

    Publication Year: 2001, Page(s):90 - 92
    Cited by:  Papers (37)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB) | HTML iconHTML

    Analytically constructed LDPC codes comprise only a very small subset of possible codes and as a result LDPC codes are still, for the most part, constructed randomly. This paper extends the class of LDPC codes that can be systematically generated by presenting a construction method for regular LDPC codes based on combinatorial designs known as Kirkman triple systems. We construct (3, ρ)-regula... View full abstract»

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  • Methods and limits of iterative multiuser decoding

    Publication Year: 2001, Page(s):45 - 47
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB) | HTML iconHTML

    Previous work has identified iterative multiuser decoding techniques that are often only limited by theoretical channel capacity. These investigations usually dealt with the case where user waveforms are decorrelated to some degree. Investigations with identical waveforms indicate that the theoretical capacity limits are not always achieved. Performance has a threshold-like behaviour, as one might... View full abstract»

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  • Using the mean reliability as a design and stopping criterion for turbo codes

    Publication Year: 2001, Page(s):27 - 29
    Cited by:  Papers (11)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB) | HTML iconHTML

    By means of the mean reliability (defined as the mean of the absolute values of log-likelihood ratios), a new design of parallel concatenated "turbo" codes is proposed. This criterion allows us to describe the behavior of the constituent decoders and, furthermore, to predict the behavior of the iterative decoder for large block lengths. The mean reliability can also be used as a stopping criterion View full abstract»

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