Lossy Joint Source-Channel Coding in the Finite Blocklength Regime
This paper finds new tight finite-blocklength bounds for the best achievable lossy joint source-channel code rate, and demonstrates that joint source-channel code design brings considerable performance advantage over a separate one in the nonasymptotic regime. A joint source-channel code maps a bloc...
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| Published in: | IEEE transactions on information theory Vol. 59; no. 5; pp. 2545 - 2575 |
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| Main Authors: | , |
| Format: | Journal Article |
| Language: | English |
| Published: |
New York, NY
IEEE
01.05.2013
Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subjects: | |
| ISSN: | 0018-9448, 1557-9654 |
| Online Access: | Get full text |
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| Summary: | This paper finds new tight finite-blocklength bounds for the best achievable lossy joint source-channel code rate, and demonstrates that joint source-channel code design brings considerable performance advantage over a separate one in the nonasymptotic regime. A joint source-channel code maps a block of k source symbols onto a length- n channel codeword, and the fidelity of reproduction at the receiver end is measured by the probability ε that the distortion exceeds a given threshold d . For memoryless sources and channels, it is demonstrated that the parameters of the best joint source-channel code must satisfy nC - kR ( d ) ≈ √( nV + k V ( d )) Q -1 (ε), where C and V are the channel capacity and channel dispersion, respectively; R ( d ) and V ( d ) are the source rate-distortion and rate-dispersion functions; and Q is the standard Gaussian complementary cumulative distribution function. Symbol-by-symbol (uncoded) transmission is known to achieve the Shannon limit when the source and channel satisfy a certain probabilistic matching condition. In this paper, we show that even when this condition is not satisfied, symbol-by-symbol transmission is, in some cases, the best known strategy in the nonasymptotic regime. |
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| Bibliography: | SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 14 |
| ISSN: | 0018-9448 1557-9654 |
| DOI: | 10.1109/TIT.2013.2238657 |