The newly released Distributed System Interface 3 ( DSI3) Bus Standard specification defines three modulation levels form which 16 valid symbols are coded. This complex structure is best decoded with symbol pattern re...
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The newly released Distributed System Interface 3 ( DSI3) Bus Standard specification defines three modulation levels form which 16 valid symbols are coded. This complex structure is best decoded with symbol pattern recognition. This paper proposes a simplification of the correlation score calculation that sharply reduces the required number of operations. Additionally, the paper describes how the pattern recognition is achieved using correlation scores and a decoding algorithm. The performance of this method is demonstrated by mean of simulations with different load models between the master and the sensors and varying noise injection on the channel. We prove than the pattern recognition can decode symbols without any error for up to 24dBm.
Network coding is a new direction in the information and communication theory. In this area algebraic coding for wire channels is based on Grassmann metric which is also called subspace metric. In the theory the main ...
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ISBN:
(纸本)9781479970124
Network coding is a new direction in the information and communication theory. In this area algebraic coding for wire channels is based on Grassmann metric which is also called subspace metric. In the theory the main problem is to construct codes with great cardinality and create fast decoding algorithms. Here, we deliver the low bound of subspace network codes. We calculate cardinality of some concrete codes and describe decoding algorithms. We show the interest cases where the cardinality approaches the upper bound.
A novel doping bits based belief propagation decoding algorithm, for rate-adaptive LDPC codes based on fixed bipartite graph code, is proposed. The proposed work modifies the decoding algorithm, by converting the punc...
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A novel doping bits based belief propagation decoding algorithm, for rate-adaptive LDPC codes based on fixed bipartite graph code, is proposed. The proposed work modifies the decoding algorithm, by converting the puncturing nodes to regular source nodes and by following the encoding rule at the decoder. The transmitted doping bits in place of punctured bits, with the modified decoding algorithm at the decoder, feed all the punctured nodes with reliable log likelihood ratios. This enables the proposed decoding algorithm to recover all punctured nodes in the early iteration. The fast convergence leads to decoder complexity reduction while providing considerable improvement in performance.
Early termination techniques are widely used in low-density party-check (LDPC) decoding since the decoding operations can be tremendously reduced. A layer stopping criterion is proposed to reduce further the operation...
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Early termination techniques are widely used in low-density party-check (LDPC) decoding since the decoding operations can be tremendously reduced. A layer stopping criterion is proposed to reduce further the operations within iterative layered LDPC decoding. The proposed criterion detects the high reliability of the soft log-likelihood ratio with a threshold in each layer. Then the layer operations can be stopped when the reliable layers are detected. The proposed criterion combined with early termination techniques can efficiently reduce the layer operations by up to 60% with a negligible loss of coding gain at E-b/N-0 of 3.2 dB.
A novel method for approximating the optimal max* operator used in Log-MAP decoding of turbo and turbo trellis-coded modulation (TTCM) codes is proposed being derived from a well-known inequality, which has not been p...
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A novel method for approximating the optimal max* operator used in Log-MAP decoding of turbo and turbo trellis-coded modulation (TTCM) codes is proposed being derived from a well-known inequality, which has not been published before. The max* operation is generalized, for the first time, and performed on n > 2 rather than n = 2 arguments, as it is the conventional approach. Complexity comparisons reveal a significant reduction in the number of operations required per decoding step for the proposed approximation, as compared with the optimal Log-MAP algorithm. Performance evaluation results are presented for both turbo and TTCM codes, showing the near optimal performance of the novel approximation method in both the additive white Gaussian noise (AWGN) and uncorrelated, i.e. fully interleaved, Rayleigh fading channels.
The prototype of the isolated words recognition software based on the phonetic decoding method with the Kullback-Leibler divergence is presented. The architecture and basic algorithms of the software are described. Fi...
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The prototype of the isolated words recognition software based on the phonetic decoding method with the Kullback-Leibler divergence is presented. The architecture and basic algorithms of the software are described. Finally, an example of application to the problem of isolated words recognition is provided.
In this study, the authors investigate the performance of soft-decision decoding of convolutional codes in receivers that employ square-law detection. Traditionally, soft-decision decoding has been considered only in ...
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In this study, the authors investigate the performance of soft-decision decoding of convolutional codes in receivers that employ square-law detection. Traditionally, soft-decision decoding has been considered only in coherent or differentially-coherent receivers. Over the past few years, the emergence of ultra-wideband (UWB) communication has brought energy detectors to prominence. In this study, the authors derive low-complexity approximations for the log-likelihood ratio (LLR) with a class of square-law detectors in UWB radios. The authors then show that performance improvements, similar to those achievable in coherent detectors, can be obtained even with energy detectors when soft-decisions are employed in a maximum-likelihood decoding algorithm. The authors also investigate the complexity and accuracy of the proposed approximations when the LLR is computed using fixed point arithmetic. An expression for the bit error probability with soft-decision decoding is derived. Several simulation results, including the error rate performance of hard-and soft-decision decoding schemes with the exact and approximate LLR values, are presented.
In this paper, a reduced complexity Log-MAP algorithm based on a non-recursive approximation of the max* operator is presented and studied for turbo trellis-coded modulation (TTCM) systems. In the algorithm, denoted a...
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In this paper, a reduced complexity Log-MAP algorithm based on a non-recursive approximation of the max* operator is presented and studied for turbo trellis-coded modulation (TTCM) systems. In the algorithm, denoted as AvN Log-MAP, the max* operation is generalized and performed on n >= 2 arguments. The approximation is derived from the Jensen inequality. The non-recursive form of the max* calculations allows to achieve significant reduction in the decoding effort in comparison to the conventional Log-MAP algorithm. Bit-error rate performance simulation results for serial and parallel TTCM schemes in the additive white Gaussian noise and uncorrelated Rayleigh fading channels show that the AvN Log-MAP algorithm performs close to the Log-MAP. Performance and complexity comparisons of the AvN Log-MAP algorithm against the Log-MAP and several relevant reduced complexity turbo decoding algorithms proposed in the literature reveal, that it offers favorable low computational effort for the price of small performance degradation.
An algorithm for generating parity-check matrices of regular low-density paritycheck codes based on permutation matrices and Steiner triple systems S(v, 3, 2), v = 2 (m) - 1, is proposed. Estimations of the rate, mini...
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An algorithm for generating parity-check matrices of regular low-density paritycheck codes based on permutation matrices and Steiner triple systems S(v, 3, 2), v = 2 (m) - 1, is proposed. Estimations of the rate, minimum distance, and girth for obtained code constructions are presented. Results of simulation of the obtained code constructions for an iterative "belief propagation" (Sum-Product) decoding algorithm applied in the case of transmission over a binary channel with additive Gaussian white noise and BPSK modulation are presented.
A new class of subcodes in rank metric is proposed;based on it, multicomponent network codes are constructed. Basic properties of subspace subcodes are considered for the family of rank codes with maximum rank distanc...
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A new class of subcodes in rank metric is proposed;based on it, multicomponent network codes are constructed. Basic properties of subspace subcodes are considered for the family of rank codes with maximum rank distance (MRD codes). It is shown that nonuniformly restricted rank subcodes reach the Singleton bound in a number of cases. For the construction of multicomponent codes, balanced incomplete block designs and matrices in row-reduced echelon form are used. A decoding algorithm for these network codes is proposed. Examples of codes with seven and thirteen components are given.
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