low encoding complexity is very important for quasi-cyclic low-density parity-check (QC-LDPC) codes used in wireless communication systems. In this paper, a new scheme is presented to construct QC-LDPC codes with low ...
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low encoding complexity is very important for quasi-cyclic low-density parity-check (QC-LDPC) codes used in wireless communication systems. In this paper, a new scheme is presented to construct QC-LDPC codes with low encoding complexity. This scheme is called two-stage particle swarm optimization (TS-PSO) algorithm, in which both the threshold and girth distribution of QC-LDPC codes are considered. The proposed scheme is composed of two stages. In the first stage, we construct a binary base matrix of QC-LDPC code with the best threshold. The matrix is constructed by combining a binary PSO algorithm and the protograph extrinsic information transfer (PEXIT) method. In the second stage, we search an exponent matrix of the QC-LDPC code with the best girth distribution. This exponent matrix is based on the base matrix obtained in the first stage. Consequently, the parity-check matrix of the QC-LDPC code with the best threshold and best girth distribution are constructed. Furthermore, bit error rate performances are compared for the QC-LDPC codes constructed by proposed scheme, the QC-LDPC code in 802.16e standard, and the QC-LDPC code in Tam's study. Simulation results show that the QC-LDPC codes proposed in this study are superior to both the 802.16e code and the Tam code on the additive white Gaussian noise (AWGN) and Rayleigh channels. Moreover, proposed scheme is easily implemented, and is flexible and effective for constructing QC-LDPC codes with low encoding complexity. Copyright (C) 2012 John Wiley & Sons, Ltd.
A construction method for girth-eight quasi-cyclic low-density parity-check codes (QC-LDPCs) with low encoding complexity is proposed in this study. To avoid short cycles and further improve the performance of the aut...
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A construction method for girth-eight quasi-cyclic low-density parity-check codes (QC-LDPCs) with low encoding complexity is proposed in this study. To avoid short cycles and further improve the performance of the authors proposed codes, the greatest common divisor (GCD)-based method is utilised to construct the information part with girth-eight of the parity-check matrix with systematic form. Furthermore, the quasi-dual-diagonal structure is adopted as the parity part of the parity-check matrix for fast encoding, which not only maintains the parity-check matrix with girth-eight, but also efficiently decreases the encodingcomplexity of their proposed codes. Simulation results show that their proposed codes perform better than Mackay's codes and the QC-LDPCs constructed by the GCD-based method, and have comparable performance compared with progressive edge growth based QC-LDPCs. Besides, their proposed codes have lower encodingcomplexity due to the property of fast encoding.
Private information retrieval (PIR) means a user retrieves a file while revealing no information on which file is being retrieved. In classic PIR, the user needs to wait for the responses of all the storage nodes. How...
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Private information retrieval (PIR) means a user retrieves a file while revealing no information on which file is being retrieved. In classic PIR, the user needs to wait for the responses of all the storage nodes. However, in general, there may be some nodes that are unresponsive, in which case it is formulated as v-robust PIR in the network coding (NC) structured distributed storage system (DSS), where v denotes the number of unresponsive nodes. We consider PIR with unresponsive nodes under the framework of NC structured DSS. In particular, the storage nodes adopt combination property with zigzag decodable (CP-ZD) storage code since it has the advantage of extremely low decoding complexity, which is promised by zigzag decoding (ZD) within a binary field. We design a v-robust PIR scheme with its download communication cost slightly larger than existing studies, but its decoding complexity is significantly reduced when compared with existing studies.
This paper presents a new kind of quasi-cyclic irregular repeat accumulate (IRA) codes based on circulant permutation matrices called QC-IRA-d codes. The presented QC-IRA-d codes have lower encodingcomplexity than tr...
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This paper presents a new kind of quasi-cyclic irregular repeat accumulate (IRA) codes based on circulant permutation matrices called QC-IRA-d codes. The presented QC-IRA-d codes have lower encodingcomplexity than traditional IRA codes and can be decoded in a partially parallel decoder like QC-LDPC codes. Simulation results show that QC-IRA-d codes have good error-correcting performance.
Prevalent predictive coding-based video compression methods rely on a heavy encoder to reduce temporal redundancy, which makes it challenging to deploy them on resource-constrained devices. Since the 1970s, distribute...
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ISBN:
(纸本)9781665468916
Prevalent predictive coding-based video compression methods rely on a heavy encoder to reduce temporal redundancy, which makes it challenging to deploy them on resource-constrained devices. Since the 1970s, distributed source coding theory has indicated that independent encoding and joint decoding with side information (SI) can achieve high-efficient compression of correlated sources. This has inspired a distributed coding architecture aiming at reducing the encodingcomplexity. However, traditional distributed coding methods suffer from a substantial performance gap to predictive coding ones. Inspired by the great success of learning-based compression, we propose the first end-to-end distributed deep video compression framework to improve the rate-distortion performance. A key ingredient is an effective SI generation module at the decoder, which helps to effectively exploit inter-frame correlations without computation-intensive encoder-side motion estimation and compensation. Experiments show that our method significantly outperforms conventional distributed video coding and H.264. Meanwhile, it enjoys 6 similar to 7x encoding speedup against DVC [1] with comparable compression performance. Code is released at https://***/Xinjie-Q/Distributed-DVC.
For wireless multi-view video system, whose abilities of storage and computation are all very weak, it is essential to have an encoder device with low-power consumption and low-complexity. In this paper, a DCT-domain ...
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ISBN:
(纸本)9780819466211
For wireless multi-view video system, whose abilities of storage and computation are all very weak, it is essential to have an encoder device with low-power consumption and low-complexity. In this paper, a DCT-domain Wyner-Ziv residual coding scheme with low encoding complexity is proposed for wireless multi-view video coding (WZRC-WMS). The scheme is designed to encode the residual frames of each view independently without any motion or disparity estimation at the encoder, so as to shift the large computational complexity to the decoder. At the decoder, the proposed scheme performs joint decoding with side information interpolated from current view and adjacent views. Experimental results show that the proposed WZRC-WMS scheme outperforms the H.263+ interframe coding about 1.9dB in rate-distortion performance, while the encodingcomplexity is only 1/17 of that of H.264 interframe coding.
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