We consider the compressive sensing of a sparse or compressible signal x E R~(M). We explicitly construct a class of measurement matrices, referred to as the low density frames, and develop decoding algorithms that pr...
详细信息
ISBN:
(纸本)9781424442959
We consider the compressive sensing of a sparse or compressible signal x E R~(M). We explicitly construct a class of measurement matrices, referred to as the low density frames, and develop decoding algorithms that produce an accurate estimate x even in the presence of additive noise. Low density frames are sparse matrices and have small storage requirements. Our decoding algorithms for these frames can be implemented in O(Md_(v)d_(c)) complexity, where d_(c) and d_(v) are the row and column weight of the frame respectively. Simulation results are provided, demonstrating that our approach significantly outperforms state-of-the-art recovery algorithms for numerous cases of interest.
A highly efficient decoding algorithm for the REMOS (Reverberation MOdeling for Speech recognition) concept for distant-talking speech recognition as proposed in [1] is suggested to reduce the computational complexity...
详细信息
A highly efficient decoding algorithm for the REMOS (Reverberation MOdeling for Speech recognition) concept for distant-talking speech recognition as proposed in [1] is suggested to reduce the computational complexity by about two orders of magnitude and thereby allowing for first real-time implementations. REMOS is based on a combined acoustic model consisting of a conventional hidden Markov model (HMM), modeling the clean speech, and a reverberation model. During recognition, the most likely clean-speech and reverberant contributions are estimated by solving an inner optimization problem for logarithmic melspectral (log-melspec) features. In this paper, two approximation techniques for the inner optimization problem are derived. Connected digit recognition experiments confirm that the computational complexity is significantly reduced. Ensuring that the global optima of the inner optimization problem are found, the decoding algorithm based on the proposed approximations even increases the recognition accuracy relative to interior point optimization techniques.
This paper discusses codes, and a decoding method, that can correct compound errors containing a mix of random and burst errors. Specifically, the paper provides a minimum compound distance that represents a compound ...
详细信息
This paper discusses codes, and a decoding method, that can correct compound errors containing a mix of random and burst errors. Specifically, the paper provides a minimum compound distance that represents a compound error correcting capacity for iterated codes, proposes a compound error correcting decoding algorithm for the code, and demonstrates that the decoding algorithm is capable of correcting compound errors up to half the minimum compound distance of the code. The proposed decoding algorithm is a generalized decoding method in which the decoding method for iterated codes indicated by Reddy and Robinson is a particular case. By this generalization, the proposed decoding algorithm can correct compound errors that cannot be corrected by conventional decoding methods. (c) 2005 Wiley Periodicals, Inc.
We consider matrix-product codes [C(1)...C(S)] . A, where C(1),...,C(S) are nested linear codes and matrix A has full rank. We compute their minimum distance and provide a decoding algorithm when A is a non-singular b...
详细信息
We consider matrix-product codes [C(1)...C(S)] . A, where C(1),...,C(S) are nested linear codes and matrix A has full rank. We compute their minimum distance and provide a decoding algorithm when A is a non-singular by columns matrix. The decoding algorithm decodes up to half of the minimum distance.
A reduced-complexity modified decoding algorithm for turbo trellis-coded modulation (TTCM) is proposed and evaluated in terms of complexity and bit error rate (BER) performance in an additive white Gaussian noise chan...
详细信息
A reduced-complexity modified decoding algorithm for turbo trellis-coded modulation (TTCM) is proposed and evaluated in terms of complexity and bit error rate (BER) performance in an additive white Gaussian noise channel. The algorithm uses an optimal approximation of the Jacobian logarithm, used in the so-called Log-MAP decoding, by means of the max operation and three piecewise-linear terms. Further computational complexity savings are obtained by applying this approximation only to the two largest values within the decoding step. To improve performance, the algorithms are also investigated using a scaling factor for the extrinsic information. Computer-simulated BER performance evaluation results and complexity comparisons are reported showing the near-optimal performance as well as noticeable implementation advantages of the proposed algorithms with respect to the Log-MAP decoding.
The binary QR codes are well known for their good behavior. The proposed algebraic decoding algorithm for decoding the (31, 16, 7) QR code with reducible generator polynomial is able to correct up to three errors in t...
详细信息
ISBN:
(纸本)9781424435197
The binary QR codes are well known for their good behavior. The proposed algebraic decoding algorithm for decoding the (31, 16, 7) QR code with reducible generator polynomial is able to correct up to three errors in the finite field GF(2(5)). The proposed algorithm is based on an application of the decoding algorithm given by Truong et al. and Chen et al. to modify the decoding algorithm proposed by Reed el al. All syndromes in the error-locator polynomial are computed in the finite field GF(2(5)). Thus, the decoding time can be reduced. Moreover, the simulation results for comparing the proposed decoding algorithm with decoding algorithm given by Reed et al. are given. This algorithm is suitable for implementation in a programmable microprocessor or special-purpose VLSI chip.
The recently proposed space-frequency-coded MIMO-OFDM systems have promised considerable performance improvement over single-antenna systems. However, in order to make multiantenna OFDM systems an attractive choice fo...
详细信息
The recently proposed space-frequency-coded MIMO-OFDM systems have promised considerable performance improvement over single-antenna systems. However, in order to make multiantenna OFDM systems an attractive choice for practical applications, implementation issues such as decoding complexity must be addressed successfully. In this paper, we propose a computationally efficient decoding algorithm for space-frequency block codes. The central part of the algorithm is a modulation-independent sphere decoding framework formulated in the complex domain. We develop three decoding approaches: a modulation-independent approach applicable to any memoryless modulation method, a QAM-specific and a PSK-specific fast decoding algorithm performing nearest-neighbor signal point search. The computational complexity of the algorithms is investigated via both analysis and simulation. The simulation results demonstrate that the proposed algorithm can significantly reduce the decoding complexity. We observe up to 75% reduction in the required FLOP count per code block compared to previously existing methods without noticeable performance degradation. Copyright (C) 2006 Hindawi Publishing Corporation. All rights reserved.
In this paper, a simplified decoding algorithm of the (23, 12, 7) Golay code with error-correcting capacity less than or equal to 3 is proposed. The simulation result of the decoding algorithm is shown that all correc...
详细信息
ISBN:
(纸本)9788955191387
In this paper, a simplified decoding algorithm of the (23, 12, 7) Golay code with error-correcting capacity less than or equal to 3 is proposed. The simulation result of the decoding algorithm is shown that all correctable error patterns are decoded successfully via the simplified decoding algorithm.
We consider problems of detecting errors in combinational circuits and algorithms for the decoding of linear codes. We show that a totally self-checking combinatorial circuit for the decoding of a binary Hamming [n, k...
详细信息
We consider problems of detecting errors in combinational circuits and algorithms for the decoding of linear codes. We show that a totally self-checking combinatorial circuit for the decoding of a binary Hamming [n, k] code can be constructed if and only if n = 2(r) - 1, r = n-k. We introduce the notion of a totally self-checking combinational circuit detecting error clusters of size at most mu;for shortened Hamming [n,k] codes, we construct totally self-checking decoding combinational circuits detecting error clusters of size at most mu, 2 <= mu < n-k. We describe single-error protected and self-checking algorithms: the extended Euclidean algorithm and decoding algorithms for binary BCH codes and Reed-Solomon codes over GF(2(m)).
Low Density Parity Check (LDPC) codes over GF(2m) show significantly higher performances than binary LDPC codes. However, the hardware complexity and area of the decoder are largely increasing. In this paper, putting ...
详细信息
ISBN:
(纸本)9781424448869
Low Density Parity Check (LDPC) codes over GF(2m) show significantly higher performances than binary LDPC codes. However, the hardware complexity and area of the decoder are largely increasing. In this paper, putting the code and decoder design together to consider, we propose a FPGA semi-parallel implementation of extended min-sum (EMS) decoding algorithm for quasi-cyclic low density parity check (QC-LDPC) codes over GF (2m). According to the regularity of their parity check matrices, QC-LDPC codes can facilitate efficient high-speed parallel decoding. The EMS decoding algorithm greatly reduces the computational complexity of processing units, check node unit (CNU). In addition, the updating calculation of the check node unit and variable node unit (VNU) can be overlapped to decrease the time latency and increase the throughput. Based on these architectures, the (486,972) QC-LDPC code over GF (4) decoder is implemented on Xilinx field programmable gate array (FPGA) Virtex4 XC4VLX160. The result shows that the maximum clock frequency is 131.411MHz and the throughput is 50Mb/s for the EMS decoder.
暂无评论