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Alfonso Martinez - One of the best experts on this subject based on the ideXlab platform.

  • ISIT - Improved information rates for Bit-Interleaved Coded Modulation
    2015 IEEE International Symposium on Information Theory (ISIT), 2015
    Co-Authors: Alfonso Martinez, Li Peng, Alex Alvarado, Albert Guillen I Fabregas
    Abstract:

    This paper shows that Bit-Interleaved Coded Modulation (BICM) over the Gaussian channel can achieve information rates larger than the so-called BICM capacity. For some labelings the improvement with respect to the BICM capacity is significant, especially at low and medium signal-to-noise ratios (SNR). Specifically, natural binary labeling is found to be both first- and second-order optimal at low SNR.

  • ISIT - Improved exponents and rates for Bit-Interleaved Coded Modulation
    2013 IEEE International Symposium on Information Theory, 2013
    Co-Authors: Li Peng, Albert Guillen I Fabregas, Alfonso Martinez
    Abstract:

    Mismatched decoding theory is applied to study the error exponents (both random-coding and expurgated) and achievable rates for Bit-Interleaved Coded Modulation (BICM). The gains achieved by constant-composition codes with respect to the the usual random codes are highlighted.

  • ISIT - Mismatched shaping schemes for Bit-Interleaved Coded Modulation
    2012 IEEE International Symposium on Information Theory Proceedings, 2012
    Co-Authors: Li Peng, Albert Guillen I Fabregas, Alfonso Martinez
    Abstract:

    We consider Bit-Interleaved Coded Modulation (BICM) schemes where, instead of the true bit or symbol probabilities and the constellation used at the transmitter, the decoder uses arbitrary probabilities or reference constellations. We study the corresponding low- and high- signal-to-noise-ratio regimes and show that even in the presence of this extra sources of mismatch, BICM has a negligible penalty with respect to Coded Modulation.

  • ITW - Bit-Interleaved Coded Modulation with shaping
    2010 IEEE Information Theory Workshop, 2010
    Co-Authors: Albert Guillen I Fabregas, Alfonso Martinez
    Abstract:

    The performance of Bit-Interleaved Coded Modulation (BICM) with shaping (i.e., non-equiprobable bit probabilities) is studied. For the AWGN channel, the rates achievable with BICM and shaping are practically identical to those of Coded Modulation or multilevel coding, virtually closing the gap that made BICM suboptimal in terms of information rates.

  • Bit-Interleaved Coded Modulation in the Wideband Regime
    IEEE Transactions on Information Theory, 2008
    Co-Authors: Alfonso Martinez, Giuseppe Caire, Albert Guillen I Fabregas, Frans M. J. Willems
    Abstract:

    The wideband regime of Bit-Interleaved Coded Modulation (BICM) in Gaussian channels is studied. The Taylor expansion of the Coded Modulation capacity for generic signal constellations at low signal-to-noise ratio (SNR) is derived and used to determine the corresponding expansion for the BICM capacity. Simple formulas for the minimum energy per bit and the wideband slope are given. BICM is found to be suboptimal in the sense that its minimum energy per bit can be larger than the corresponding value for Coded Modulation schemes. The minimum energy per bit using standard Gray mapping on M-PAM or M 2 -QAM is given by a simple formula and shown to approach - 0.34 dB as M increases. Using the low SNR expansion, a general tradeoff between power and bandwidth in the wideband regime is used to show how a power loss can be traded off against a bandwidth gain.

Albert Guillen I Fabregas - One of the best experts on this subject based on the ideXlab platform.

  • ISIT - Improved information rates for Bit-Interleaved Coded Modulation
    2015 IEEE International Symposium on Information Theory (ISIT), 2015
    Co-Authors: Alfonso Martinez, Li Peng, Alex Alvarado, Albert Guillen I Fabregas
    Abstract:

    This paper shows that Bit-Interleaved Coded Modulation (BICM) over the Gaussian channel can achieve information rates larger than the so-called BICM capacity. For some labelings the improvement with respect to the BICM capacity is significant, especially at low and medium signal-to-noise ratios (SNR). Specifically, natural binary labeling is found to be both first- and second-order optimal at low SNR.

  • ISIT - Improved exponents and rates for Bit-Interleaved Coded Modulation
    2013 IEEE International Symposium on Information Theory, 2013
    Co-Authors: Li Peng, Albert Guillen I Fabregas, Alfonso Martinez
    Abstract:

    Mismatched decoding theory is applied to study the error exponents (both random-coding and expurgated) and achievable rates for Bit-Interleaved Coded Modulation (BICM). The gains achieved by constant-composition codes with respect to the the usual random codes are highlighted.

  • ISIT - Mismatched shaping schemes for Bit-Interleaved Coded Modulation
    2012 IEEE International Symposium on Information Theory Proceedings, 2012
    Co-Authors: Li Peng, Albert Guillen I Fabregas, Alfonso Martinez
    Abstract:

    We consider Bit-Interleaved Coded Modulation (BICM) schemes where, instead of the true bit or symbol probabilities and the constellation used at the transmitter, the decoder uses arbitrary probabilities or reference constellations. We study the corresponding low- and high- signal-to-noise-ratio regimes and show that even in the presence of this extra sources of mismatch, BICM has a negligible penalty with respect to Coded Modulation.

  • ITW - Bit-Interleaved Coded Modulation with shaping
    2010 IEEE Information Theory Workshop, 2010
    Co-Authors: Albert Guillen I Fabregas, Alfonso Martinez
    Abstract:

    The performance of Bit-Interleaved Coded Modulation (BICM) with shaping (i.e., non-equiprobable bit probabilities) is studied. For the AWGN channel, the rates achievable with BICM and shaping are practically identical to those of Coded Modulation or multilevel coding, virtually closing the gap that made BICM suboptimal in terms of information rates.

  • Bit-Interleaved Coded Modulation in the Wideband Regime
    IEEE Transactions on Information Theory, 2008
    Co-Authors: Alfonso Martinez, Giuseppe Caire, Albert Guillen I Fabregas, Frans M. J. Willems
    Abstract:

    The wideband regime of Bit-Interleaved Coded Modulation (BICM) in Gaussian channels is studied. The Taylor expansion of the Coded Modulation capacity for generic signal constellations at low signal-to-noise ratio (SNR) is derived and used to determine the corresponding expansion for the BICM capacity. Simple formulas for the minimum energy per bit and the wideband slope are given. BICM is found to be suboptimal in the sense that its minimum energy per bit can be larger than the corresponding value for Coded Modulation schemes. The minimum energy per bit using standard Gray mapping on M-PAM or M 2 -QAM is given by a simple formula and shown to approach - 0.34 dB as M increases. Using the low SNR expansion, a general tradeoff between power and bandwidth in the wideband regime is used to show how a power loss can be traded off against a bandwidth gain.

Inkyu Lee - One of the best experts on this subject based on the ideXlab platform.

  • quasi cyclic low density parity check codes for space time bit interleaved Coded Modulation
    IEEE Communications Letters, 2008
    Co-Authors: Songnam Hong, Sunghwan Kim, Dongjoon Shin, Inkyu Lee
    Abstract:

    In this letter, it is shown that the diversity order of space-time Bit-Interleaved Coded Modulation (ST-BICM) system is determined by the number of submatrices having linearly independent column vectors in a parity-check matrix of quasicyclic low-density parity-check (QC-LDPC) code. It is also proved that this diversity order can be derived from the base matrix of QC-LDPC code, which can make it easy to design QC-LDPC codes suitable for ST-BICM systems. Finally, the simulation results are provided to confirm the analytical results.

  • Mapping Optimization for Space–Time Bit-Interleaved Coded Modulation With Iterative Decoding
    IEEE Transactions on Communications, 2007
    Co-Authors: Lee Wook Bong, Jungho Cho, Chang Kyung Sung, Hwangjun Song, Inkyu Lee
    Abstract:

    For space-time Bit-Interleaved Coded Modulation (ST-BICM) systems with iterative decoding, the overall performance is affected by the chosen mapping. In bit-error rate (BER) curves, one mapping reaches an error floor (EF) at a low signal-to-noise ratio (SNR), while other mappings result in a lower EF at a higher SNR. The constellation mappings are divided into groups where each group exhibits a distinctive BER curve. We show that the convergence abscissa of the system depends on the average total bit errors and the harmonic mean of the minimum squared Euclidean distance. In this letter, we characterize all mapping groups for ST-BICM with 8-phase-shift keying and present the optimal selection for each mapping group over independent fading channels

  • ICC - Code construction for space-time Bit-Interleaved Coded Modulation systems
    2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577), 2004
    Co-Authors: Inkyu Lee, C.-e.w. Sundberg
    Abstract:

    Bit-Interleaved Coded Modulation schemes give diversity gains on fading channels with higher order Modulation constellations combined with conventional binary convolutional codes. By employing multiple transmit and receive antennas, both extended range and/or improved bandwidth efficiency can be achieved in space-time Bit-Interleaved Coded Modulation schemes. In this paper, we analyze the performance of this space-time coding scheme in a narrow band flat fading channel and single carrier modems. We give constructive binary codes that yield maximum diversity. We also show that the puncturing mechanism in general fails to achieve the full diversity in such a scheme.

  • Space-time Bit-Interleaved Coded Modulation for OFDM systems
    IEEE Transactions on Signal Processing, 2004
    Co-Authors: Inkyu Lee, A.m. Chan, C.-e.w. Sundberg
    Abstract:

    Space-time coding techniques significantly improve transmission efficiency in radio channels by using multiple transmit and/or receive antennas and coordination of the signaling over these antennas. Bit-Interleaved Coded Modulation gives good diversity gains with higher order Modulation schemes using well-known binary convolutional codes on a single transmit and receive antenna link. By using orthogonal frequency division multiplexing (OFDM), wideband transmission can be achieved over frequency-selective fading radio channels without adaptive equalizers. In this correspondence, we combine these three ideas into a family of flexible space-time coding methods. The pairwise error probability is analyzed based on the correlated fading assumption. Near-optimum iterative decoders are evaluated by means of simulations for slowly varying wireless channels. Theoretical evaluation of the achievable degree of diversity is also presented. Significant performance gains over the wireless local area network (LAN) 802.11a standard system are reported.

  • Design of simplified receiver for space-time Bit-Interleaved Coded Modulation systems
    The 57th IEEE Semiannual Vehicular Technology Conference 2003. VTC 2003-Spring., 1
    Co-Authors: Inkyu Lee, C.-e.w. Sundberg
    Abstract:

    In this paper, we study a new family of bandwidth efficient flexible space-time coding schemes which combine Bit-Interleaved Coded Modulation with multiple transmit and receive antennas in a narrow band flat fading channel. We address receiver complexity for a large number of transmit antennas and higher order Modulation constellations. Simplified receivers utilizing tentative decisions are proposed and evaluated by means of simulations. Tradeoffs between complexity reduction and performance loss are presented. A system with 4 transmits antennas with an 8 fold complexity reduction and a performance loss of about 1 dB is demonstrated.

Giuseppe Caire - One of the best experts on this subject based on the ideXlab platform.

  • bit interleaved Coded Modulation
    2008
    Co-Authors: Giuseppe Caire, G Taricco, E Biglieri
    Abstract:

    Zehavi (1992) showed that the performance of Coded Modulation over a Rayleigh fading channel can be improved by bit-wise interleaving the encoder output and by using an appropriate soft-decision metric as an input to a Viterbi decoder. The goal of this paper is to present in a comprehensive fashion the theory underlying Bit-Interleaved Coded Modulation, to provide tools for evaluating its performance, and to give guidelines for its design.

  • Bit-Interleaved Coded Modulation in the Wideband Regime
    IEEE Transactions on Information Theory, 2008
    Co-Authors: Alfonso Martinez, Giuseppe Caire, Albert Guillen I Fabregas, Frans M. J. Willems
    Abstract:

    The wideband regime of Bit-Interleaved Coded Modulation (BICM) in Gaussian channels is studied. The Taylor expansion of the Coded Modulation capacity for generic signal constellations at low signal-to-noise ratio (SNR) is derived and used to determine the corresponding expansion for the BICM capacity. Simple formulas for the minimum energy per bit and the wideband slope are given. BICM is found to be suboptimal in the sense that its minimum energy per bit can be larger than the corresponding value for Coded Modulation schemes. The minimum energy per bit using standard Gray mapping on M-PAM or M 2 -QAM is given by a simple formula and shown to approach - 0.34 dB as M increases. Using the low SNR expansion, a general tradeoff between power and bandwidth in the wideband regime is used to show how a power loss can be traded off against a bandwidth gain.

  • ISIT - Bit-Interleaved Coded Modulation revisited: A mismatched decoding perspective
    2008 IEEE International Symposium on Information Theory, 2008
    Co-Authors: Alfonso Martinez, Giuseppe Caire, Albert Guillen I Fabregas, Frans M. J. Willems
    Abstract:

    We revisit the information-theoretic analysis of bit- interleaved Coded Modulation (BICM) by modeling the BICM decoder as a mismatched decoder. The mismatched-decoding model is well-defined for finite, yet arbitrary, block lengths, and captures the channel memory among the bits belonging to the same symbol. The generalized mutual information of the mismatched decoder coincides with the infinite-interleaver BICM capacity, where BICM is modeled as a set of independent parallel binary-input channels whose output is the bitwise log-likelihood ratio. The error exponent -and hence the cutoff rate- of the BICM mismatched decoder is upper bounded by that of Coded Modulation and may thus be lower than in the infinite-interleaved model. For binary reflected Gray mapping in Gaussian channels the loss in error exponent is small.

  • ISIT - Bit-Interleaved Coded Modulation in the Wideband Regime
    2007 IEEE International Symposium on Information Theory, 2007
    Co-Authors: Alfonso Martinez, Albert Guillen I Fabregas, Giuseppe Caire
    Abstract:

    This paper studies the wideband regime of bit- interleaved Coded Modulation (BICM) in Gaussian channels. Simple formulas for the minimum energy per bit and the wideband slope, both for Coded Modulation and for Bit-Interleaved Coded Modulation, are given. The wideband slope can be decomposed into the product of two terms, respectively due to the fading characteristics and the Modulation and binary labeling rule. BICM is found to be suboptimal in the sense that its minimum energy per bit can be larger than the corresponding value for Coded Modulation schemes. The minimum energy per bit using standard Gray mapping on M-PAM, or M 2-QAM is given by a simple formula, and shown to approach -0.34 dB as M increases.

  • Error probability analysis of Bit-Interleaved Coded Modulation
    IEEE Transactions on Information Theory, 2006
    Co-Authors: Alfonso Martinez, Albert Guillen I Fabregas, Giuseppe Caire
    Abstract:

    This correspondence presents a simple method to accurately compute the error probability of Bit-Interleaved Coded Modulation (BICM). Thanks to the binary-input output-symmetric (BIOS) nature of the channel, the pairwise error probability (PEP) is equal to the tail probability of a sum of random variables with a particular distribution. This probability is in turn computed with a saddlepoint approximation. Its precision is numerically validated for Coded transmission over standard Gaussian noise and fully interleaved fading channels for both convolutional and turbo-like codes.

C.-e.w. Sundberg - One of the best experts on this subject based on the ideXlab platform.

  • ICC - Code construction for space-time Bit-Interleaved Coded Modulation systems
    2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577), 2004
    Co-Authors: Inkyu Lee, C.-e.w. Sundberg
    Abstract:

    Bit-Interleaved Coded Modulation schemes give diversity gains on fading channels with higher order Modulation constellations combined with conventional binary convolutional codes. By employing multiple transmit and receive antennas, both extended range and/or improved bandwidth efficiency can be achieved in space-time Bit-Interleaved Coded Modulation schemes. In this paper, we analyze the performance of this space-time coding scheme in a narrow band flat fading channel and single carrier modems. We give constructive binary codes that yield maximum diversity. We also show that the puncturing mechanism in general fails to achieve the full diversity in such a scheme.

  • Space-time Bit-Interleaved Coded Modulation for OFDM systems
    IEEE Transactions on Signal Processing, 2004
    Co-Authors: Inkyu Lee, A.m. Chan, C.-e.w. Sundberg
    Abstract:

    Space-time coding techniques significantly improve transmission efficiency in radio channels by using multiple transmit and/or receive antennas and coordination of the signaling over these antennas. Bit-Interleaved Coded Modulation gives good diversity gains with higher order Modulation schemes using well-known binary convolutional codes on a single transmit and receive antenna link. By using orthogonal frequency division multiplexing (OFDM), wideband transmission can be achieved over frequency-selective fading radio channels without adaptive equalizers. In this correspondence, we combine these three ideas into a family of flexible space-time coding methods. The pairwise error probability is analyzed based on the correlated fading assumption. Near-optimum iterative decoders are evaluated by means of simulations for slowly varying wireless channels. Theoretical evaluation of the achievable degree of diversity is also presented. Significant performance gains over the wireless local area network (LAN) 802.11a standard system are reported.

  • Design of simplified receiver for space-time Bit-Interleaved Coded Modulation systems
    The 57th IEEE Semiannual Vehicular Technology Conference 2003. VTC 2003-Spring., 1
    Co-Authors: Inkyu Lee, C.-e.w. Sundberg
    Abstract:

    In this paper, we study a new family of bandwidth efficient flexible space-time coding schemes which combine Bit-Interleaved Coded Modulation with multiple transmit and receive antennas in a narrow band flat fading channel. We address receiver complexity for a large number of transmit antennas and higher order Modulation constellations. Simplified receivers utilizing tentative decisions are proposed and evaluated by means of simulations. Tradeoffs between complexity reduction and performance loss are presented. A system with 4 transmits antennas with an 8 fold complexity reduction and a performance loss of about 1 dB is demonstrated.