DocumentCode :
379949
Title :
Rate-based versus distortion-based optimal joint source-channel coding
Author :
Hamzaoui, Raouf ; Stankovic, Vladimir ; Xiong, Zixiang
Author_Institution :
Inst. fur Informatik, Leipzig Univ., Germany
fYear :
2002
fDate :
2002
Firstpage :
63
Lastpage :
72
Abstract :
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.
Keywords :
combined source-channel coding; error correction codes; error detection codes; image coding; rate distortion theory; visual communication; wavelet transforms; JPEG 2000; SPIHT coder; binary symmetric channel; channel codes; distortion-based optimal joint source-channel coding; distortion-based optimization; embedded wavelet bitstream; error correction; error detection; expected distortion; iterative improvement algorithm; local search algorithm; lower bound; rate-based optimal joint source-channel coding; rate-based optimal solution; time complexity; Bit rate; Convolutional codes; Cyclic redundancy check; Decoding; Distortion measurement; Error correction codes; Iterative algorithms; Protection; Robustness; Turbo codes;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Data Compression Conference, 2002. Proceedings. DCC 2002
ISSN :
1068-0314
Print_ISBN :
0-7695-1477-4
Type :
conf
DOI :
10.1109/DCC.2002.999944
Filename :
999944
Link To Document :
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