With the rapid development of wireless network and multimedia technology,the efficient transmission over unreliable channel is becoming more and more *** error control technique for video coding and transmission has d...
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With the rapid development of wireless network and multimedia technology,the efficient transmission over unreliable channel is becoming more and more *** error control technique for video coding and transmission has drawn considerable attention,tries to recover the data loss and bit errors due to congestion or physical channel ***,there are three kinds of error control schemes,namely,error resilient coding at the encoder,error concealment at the decoder and the retransmission in the transport *** this paper,an error control scheme is proposed which uses the soft information in channeldecoding to recover the corrupted bit *** bit error is detected in a slice,soft information of channeldecoding is employed to locate it,and the wrong bits are flipped and decoded again at the beginning of the *** combination of XOR at source and the syntax checking of H.264 decoder has increased the error detection rate from around 60%to 99%without increasing source *** results show that,when the same error concealing algorithm is used,the PSNR of the proposed scheme using soft information of channeldecoding at the decoder is 1-2dB higher than that using the traditional method.
joint source-channel decoding (JSCD) has been shown to be effective for multimedia transmission over time-varying channels. In this paper, we present a method for jointsource-channel soft decision decoding of variabl...
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ISBN:
(纸本)9780769536101
joint source-channel decoding (JSCD) has been shown to be effective for multimedia transmission over time-varying channels. In this paper, we present a method for jointsource-channel soft decision decoding of variable-length encoded multiple sources. Compared with the single sourcedecoding scheme addressed by Marion Jeanne, the proposed technique is more practical in wideband wireless communications. Simulation results show our new method obtains substantial improvements with a minor increasing of complexity. For two sources, the gain in SNR is around 1.5dB when symbol-error rate (SER) reaches 10(-2) and around 1.3dB when SER=10(-3).
With random linear network coding, mixed packets contain in their headers information about the coding operations performed on the original packets to allow their recovery by the receiver. This introduces an overhead ...
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ISBN:
(纸本)9781479962174
With random linear network coding, mixed packets contain in their headers information about the coding operations performed on the original packets to allow their recovery by the receiver. This introduces an overhead that could be significant if the packet size is relatively small w.r.t. the size of the generation. In this paper, we propose to remove the part of the added header related to the network coding coefficients and to consider network decoding as a source separation problem. This problem is addressed using a maximum a posteriori estimation technique. It exploits some a priori information related to the content of the headers added to the original packets by the upper layers of the protocol stack, before network coding. Experiments show that, despite the fact that traditional source separation techniques are completely inadequate to handle this scenario, the proposed approach is able to recover all packets within streams of thousands of generations without a single decoding error.(1)
Since joint source-channel decoding is capable of exploiting the residual redundancy in the source signals for improving the attainable error resilience, it has attracted substantial attention. In this treatise, the a...
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Since joint source-channel decoding is capable of exploiting the residual redundancy in the source signals for improving the attainable error resilience, it has attracted substantial attention. In this treatise, the authors study iterative source-channeldecoding (ISCD) aided video communications, where the video signal redundancy is modelled by a first-order Markov process. Firstly, the authors derive reduced-complexity formulas for the first-order Markov modelling (FOMM) aided sourcedecoding. Then they propose a bit-based iterative horizontal-vertical scanline model (IHVSM) aided sourcedecoding algorithm, where a horizontal and a vertical source decoder are employed for exchanging their extrinsic information using the iterative decoding philosophy. The iterative IHVSM aided decoder is then employed in a forward error correction (FEC) encoded uncompressed video transmission scenario, where the IHVSM and the FEC decoder exchange softbit-information for performing turbo-like ISCD for the sake of improving the reconstructed video quality. Finally, the authors benchmark the attainable system performance against a near-lossless H.264/AVC video communication system and the existing FOMM-based softbit sourcedecoding scheme. The authors simulation results show that E-b/N-0 improvements in excess of 2.8 dB are attainable by the proposed technique in uncompressed video applications.
Multi media transmission over error-prone channels such as wireless channels has recently motivated the research on the jointsource-channel (de)coding (JSCC, JSCD) technique. In this paper, we present a new JSCD meth...
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ISBN:
(纸本)9780769536101
Multi media transmission over error-prone channels such as wireless channels has recently motivated the research on the jointsource-channel (de)coding (JSCC, JSCD) technique. In this paper, we present a new JSCD method, which extends the joint area to the process of demodulation soft decision to enlarge the application fields of JSCD. The proposed method designs a technique of dynamic source redundancy detection and generalizes the Viterbi algorithm in a TDM system with scrambler. Simulation results show that our new method can obtain substantial improvements with a minor increasing of complexity, especially in the bad channel environment. For a TDM system with 30% occupied slots, the gain in SNR is around 4.4dB when SER reaches 10(-2).
This paper presents a method for jointdecoding of JPEG2000 bitstreams and Reed-Solomon codes in the context of unequal loss protection. When the Reed-Solomon decoder is unable to retrieve the erased source symbols, t...
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ISBN:
(纸本)9781424414833
This paper presents a method for jointdecoding of JPEG2000 bitstreams and Reed-Solomon codes in the context of unequal loss protection. When the Reed-Solomon decoder is unable to retrieve the erased source symbols, the proposed joint decoder searches through the set of possible erased source symbols, making use of error resilience features of JPEG2000 to retrieve correct symbols. The joint decoder can be used as an add-on module to some of the existing schemes for unequal loss protection, and can improve the PSNR of decoded images by over 10 dB in some cases.
We investigate the complexity of jointsource-channel maximum a posteriori (MAP) decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy me...
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We investigate the complexity of jointsource-channel maximum a posteriori (MAP) decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy memoryless channel. As established previously the MAP decoding can be performed by a Viterbi-like algorithm on a trellis whose states are triples of the states of the Markov source, source coder and convolutional coder. The large size of the product space (in the order of K-2 N, where K is the number of source symbols and N is the number of states of the convolutional coder) appears to prohibit such a scheme. We show that for finite impulse response convolutional codes, the state space size of joint source-channel decoding can be reduced to O(K-2+N log N), hence the decoding time becomes O(TK2 + TN log N), where T is the length in bits of the decoded bitstream. We further prove that an additional complexity reduction can be achieved when K > N, if the logarithm of the source transition probabilities satisfy the so-called Monge property. This decrease becomes more significant as the tree structure of the source code is more unbalanced. The reduction factor ranges between O(KIN) (for a fixed-length source code) and O(K/log N) (for Golomb-Rice code).
We investigate the complexity of jointsource-channel maximum a posteriori (MAP) decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy me...
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ISBN:
(纸本)0780391519
We investigate the complexity of jointsource-channel maximum a posteriori (MAP) decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy memoryless channel. As established previously the MAP decoding can be performed by a Viterbi-like algorithm on a trellis whose states are triples of the states of the Markov source, source coder and convolutional coder. The large size of the product space (in the order of K-2 N, where K is the number of source symbols and N is the number of states of the convolutional coder) appears to prohibit such a scheme. We show that for finite impulse response convolutional codes, the state space size of joint source-channel decoding can be reduced to O(K-2+N log N), hence the decoding time becomes O(TK2 + TN log N), where T is the length in bits of the decoded bitstream. We further prove that an additional complexity reduction can be achieved when K > N, if the logarithm of the source transition probabilities satisfy the so-called Monge property. This decrease becomes more significant as the tree structure of the source code is more unbalanced. The reduction factor ranges between O(KIN) (for a fixed-length source code) and O(K/log N) (for Golomb-Rice code).
In this paper, we present a symbol-level joint source-channel decoding (JSCD) algorithm for transmission of convolutionally encoded variable-length codes (VLCs). The proposed algorithm is based on a two-dimensional st...
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ISBN:
(纸本)9781467330701;9781467348171
In this paper, we present a symbol-level joint source-channel decoding (JSCD) algorithm for transmission of convolutionally encoded variable-length codes (VLCs). The proposed algorithm is based on a two-dimensional state representation which leads to a three-dimensional code trellis. JSCD on this trellis is realized by employing a modified BCJR algorithm which allows to fully exploit the symbol-level source a priori information. Experimental results indicate that the proposed JSCD scheme achieves high robustness against channel noises.
This article presents a low-power decoder design for joint source-channel decoding (JSCD) based on a novel unequal error protection (UEP) scheme over additive white gaussian noise (AWGN) channels. Conventional JSCD sc...
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This article presents a low-power decoder design for joint source-channel decoding (JSCD) based on a novel unequal error protection (UEP) scheme over additive white gaussian noise (AWGN) channels. Conventional JSCD schemes, adopting low-density parity check (LDPC) codes for multimedia devices, typically operate at a fixed-time decoding loop, regardless of the quality of data received. We present a JSCD scheme that achieves reduction in power through minimum energy decoding and dynamic voltage and frequency scaling (DVFS). Consequently, up to 39% power reduction is achieved in Foreman, Akiyo, and Mobile video streams without performance degradation in reconstructed video quality.
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