Rate-based versus distortion-based optimal joint source-channel coding

We consider a joint source-channel coding system that protects an embedded wavelet bitstream against noise using a finite family of channel codes with error detection and error correction capability. The performance of this system may be measured by the expected distortion or by the expected number...

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Vydáno v:Proceedings DCC 2002. Data Compression Conference s. 63 - 72
Hlavní autoři: Hamzaoui, R., Stankovic, V., Zixiang Xiong
Médium: Konferenční příspěvek
Jazyk:angličtina
Vydáno: IEEE 2002
Témata:
Bit rate
Convolutional codes
Cyclic redundancy check
Decoding
Distortion measurement
Error correction codes
Iterative algorithms
Protection
Robustness
Turbo codes
ISBN:0769514774, 9780769514772
ISSN:1068-0314
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Popis
Shrnutí:We consider a joint source-channel coding system that protects an embedded wavelet bitstream against noise using a finite family of channel codes with error detection and error correction capability. The performance of this system may be measured by the expected distortion or by the expected number of correctly received source bits subject to a target total transmission rate. Whereas a rate-based optimal solution can be found in linear time, the computation of a distortion-based optimal solution is prohibitive. Under the assumption of the convexity of the operational distortion-rate function of the source coder, we give a lower bound on the expected distortion of a distortion-based optimal solution that depends only on a rate-based optimal solution. Then we show that a distortion-based optimal solution provides a stronger error protection than a rate-based optimal solution and exploit this result to reduce the time complexity of the distortion-based optimization. Finally, we propose a fast iterative improvement algorithm that starts from a rate-based optimal solution and converges to a local minimum of the expected distortion. Experimental results for a binary symmetric channel with the SPIHT coder and JPEG 2000 show that our lower bound is close to optimal. Moreover, the solution given by our local search algorithm has about the same quality as a distortion-based optimal solution, whereas its complexity is much lower than that of the previous best solution.
ISBN:0769514774
9780769514772
ISSN:1068-0314
DOI:10.1109/DCC.2002.999944