Iterative joint source-channel decoding of variable length encoded video sequences exploiting source semantics

This paper proposes an iterative joint source-channel decoding of variable length codes (VLC) sequences exploiting the inherent redundancy in the source stream, namely (i) the VLC structure (ii) the sequence structure. An optimum soft-input soft-output (SISO) maximum likelihood (ML) decoder of VLC sequences which is able to exploit both types of redundancies is first proposed, and shown to be optimal. This algorithm is then used in an iterative joint source-channel decoding. Performance results for transmitting video over AWGN channels are presented and compared to the soft-output Viterbi algorithm (SOVA) VLC decoder.