Joint source-channel decoding with iterative algorithms

Ideas from iterative decoding of concatenated channel codes are adopted for joint source-channel decoding. Extrinsic information from a soft-in/soft-out channel decoder is used as a-priori information for the new soft-in/soft-out source decoder. The source decoder processes soft channel outputs, extrinsic information from the channel decoder, and source-statistics and it computes extrinsic information for the data-bits that again is used as a-priori information for the channel decoder. In this novel iterative approach to joint source-channel decoding the redundancies within the data-bits of the source encoder are used as an additional source of information in contrast to iterative channel decoding, where further information on the data-bits is drawn from the redundancy-bits of some additional, independent channel-coding scheme.