In this paper, we present a high-rate M-ary quadrature amplitude modulation (M-QAM) space-time labeling diversity (STLD) system that retains the robust error performance of the conventional STLD system. The high-rate ...
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In this paper, we present a high-rate M-ary quadrature amplitude modulation (M-QAM) space-time labeling diversity (STLD) system that retains the robust error performance of the conventional STLD system. The high-rate STLD is realised by expanding the conventional STLD via a unitary matrix transformation. Robust error performance of the high-rate STLD is achieved by incorporating trellis coding into the mapping of additional bits to high-rate codes. The comparison of spectral efficiency between the proposed trellis code-aided high-rate STLD (TC-STLD) and the conventional STLD shows that TC-STLD with 16-QAM and 64-QAM respectively achieves a 12.5% and 8.3% increase in spectral efficiency for each additional bit sent with the transmitted high-rate codeword. Moreover, we derive an analytical bound to predict the average bit error probability performance of TC-STLD over Rayleigh frequency-flat fading channels. The analytical results are verified by Monte Carlo simulation results, which show that the derived analytical bounds closely predict the average bit error probability performance at high signal-to-noise ratios (SNR). Simulation results also show that TC-STLD with 1 additional bit achieves an insignificant SNR gain of approximately 0.05dB over the conventional STLD, while TC-STLD with 2 additional bits achieves an SNR gain of approximately 0.12dB.
A new tight analytical upper bound is presented for the performance of finite-delay symbol-by-symbol (SBS) Abend-Fritchman-like decoding of trellis-encoded data crossing arbitrary (eventually time-varying) discrete me...
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A new tight analytical upper bound is presented for the performance of finite-delay symbol-by-symbol (SBS) Abend-Fritchman-like decoding of trellis-encoded data crossing arbitrary (eventually time-varying) discrete memoryless channels (DMC's). On the basis of this bound, a related criterion for the optimal design of trellis codes with SBS decoding is then proposed. It gives rise to an effective procedure for the construction of good trellis codes (generally time varying and nonlinear) with assigned decoding complexity.
A novel code combining system based on Reed-Muller codes is presented. Because of their simple structure RM codes are simple to decode using a trellis based soft maximum likelihood decoder (SMLD). The decoder exploits...
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A novel code combining system based on Reed-Muller codes is presented. Because of their simple structure RM codes are simple to decode using a trellis based soft maximum likelihood decoder (SMLD). The decoder exploits the modular structure of the RM code to construct a set of nested trellises which minimise the complexity of the decoder by re-using the results of previous decoding attempts. A protocol utilising this technique to produce an efficient code combining ARQ-scheme is also introduced.
trellis coded modulation (TCM) concept is applied to the mode constellation points of orbital angular momentum (OAM) modulation. OAM modulation considers the multiple OAM modes as additional constellation points and m...
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trellis coded modulation (TCM) concept is applied to the mode constellation points of orbital angular momentum (OAM) modulation. OAM modulation considers the multiple OAM modes as additional constellation points and maps a first part of a block of information bits to the transmitting OAM modes. Therefore, spatial multiplexing gains are retained and spectral efficiency is boosted. The second part of the block of information bits is mapped to a complex symbol using conventional digital modulation schemes. At any particular time instant, only one OAM mode is active. The receiver estimates the transmitted symbol and the active OAM mode, then uses the two estimates to retrieve the original block of data bits. Simulation reveals that with the TCM employed both for the OAM constellation points and the signal constellation points, a considerable bit error rate (BER) gain can be obtained under all turbulence conditions, compared with that of the no coding scheme.
In general, the performance of partial response maximum-likelihood (PRML) system is degraded by nonlinear distortion and high frequency noise in high-density digital magnetic recording. Conventional PRML system For si...
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In general, the performance of partial response maximum-likelihood (PRML) system is degraded by nonlinear distortion and high frequency noise in high-density digital magnetic recording. Conventional PRML system For single-track recording improves the performance when high order PRML systems and high rate codes are adopted. But, in general it is difficult to realize LSI circuits for high order PRML system and high rate code. In this paper, a trellis coded class four partial response maximum-likelihood (TC-PR4ML) system for high density two-track digital magnetic recording is proposed. Our two-track recording method can increase the coding rate over 1, which contributes to a decrease in both degradation effects from partial erasure, one of nonlinear distortions, and high frequency noise in high density recording. The error rate performance of the proposed system is obtained by computer simulation taking account of the partial erasure and it is compared with that of a conventional NRZ coded class four partial response maximum-likelihood (NRZ-PR4ML) system. The results show that the proposed system is hardly affected by partial erasure and keeps good performance in high density recording.
A pyramid source code is a code that assigns equal-length binary strings to all reproduction codevectors of equal (weighted) ii norm. A pyramid source encoding is partitioned into two concatenated mappings;the first f...
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A pyramid source code is a code that assigns equal-length binary strings to all reproduction codevectors of equal (weighted) ii norm. A pyramid source encoding is partitioned into two concatenated mappings;the first from source word to reproduction codeword within a codebook;the second from the reproduction codevector to a binary string, The first mapping allows distortion and is accomplished using lattice quantization or trellis-coded quantization. The second mapping is noiseless and is denoted as enumeration. Efficient pyramid enumeration encoding and decoding algorithms are presented, for use with fixed-rate or variable-rate pyramid lattice and trellis codes.
We present a rate 8/10 matched-spectral-null (MSN) trellis codec chip which can increase noise tolerance in partial-response channels applicable to digital magnetic recording. The Viterbi detector in this codec featur...
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We present a rate 8/10 matched-spectral-null (MSN) trellis codec chip which can increase noise tolerance in partial-response channels applicable to digital magnetic recording. The Viterbi detector in this codec features an area-efficient pipelined architecture and a modulo metric normalization technique. The chip was implemented in a 1.2-mu-m CMOS process with a die size of 22 mm2. It offers a 12-Mb/s data rate when operating at 30 MHz. Experimental results verified the predicted coding gain of 2.8 dB relative to the uncoded system at a bit-error rate of 10(-7).
Tail biting trellis codes and block concatenated codes are discussed from random coding arguments. Error exponents and decoding complexity for generalized tail biting (GTB) random trellis codes, and their relationship...
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Tail biting trellis codes and block concatenated codes are discussed from random coding arguments. Error exponents and decoding complexity for generalized tail biting (GTB) random trellis codes, and their relationships are derived, where the GTB trellis codes consist of full tail biting (FTB) trellis codes, partial tail biting (PTB) trellis codes and direct truncated (DT) trellis codes. We show that the PTB trellis codes at all rates except for low rates are superior to all of the GTB trellis codes, in a sense that they have smaller upper bound on the probability of decoding error for given decoding complexity. We then propose the generalized version of the block concatenated codes constructed by the GTB trellis inner codes, and derive error exponents and the decoding complexity for the proposed code. The results obtained show that the DT trellis inner codes are effective among the GTB trellis inner codes for constructing the generalized version of the concatenated codes to keep the same decoding complexity as the original concatenated codes. We also show that larger error exponents are obtained by the generalized version of concatenated codes, if the decoding complexity is allowed to be larger than that of the original concatenated code, although it is still in polynomial order.
A trellis source code and novel variable-length lossless code are used in transform coded excitation audio coding. Implemented within the extended adaptive multi-rate wideband (AMR-WB+) audio coding framework, the pro...
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ISBN:
(纸本)9781424414833
A trellis source code and novel variable-length lossless code are used in transform coded excitation audio coding. Implemented within the extended adaptive multi-rate wideband (AMR-WB+) audio coding framework, the proposed quantization and lossless coding method provide between 0.4 and 0.7 dB increase in signal-to-noise ratio over the E-8 lattice VQ and spherical lossless code used in the AMR-WB+ standard.
An efficient method is proposed to evaluate the block error probability of trellis codes. The notion of correct state on the most likely paths in Viterbi decoding on additive white Gaussian noise (AWGN) channels is in...
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An efficient method is proposed to evaluate the block error probability of trellis codes. The notion of correct state on the most likely paths in Viterbi decoding on additive white Gaussian noise (AWGN) channels is introduced. The probability that a state is correct and the probability that the state following a correct state is also correct are evaluated by simulation. These probabilities do not depend on block length. Then the block error probability for any given block length is estimated by simple calculation from the forementioned probabilities. This method is applied for some specific 8-PSK Ungerboeck codes with 2(4), 2(5), and 2(6) states. The results show that the values obtained by this method are very close to those by simulation. It is concluded that this method is very effective.
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