Joint source-channel soft decoding of Huffman codes with turbo-codes

We present a new method for using a priori information at a bit level in the decoding of Huffman codes. Its basic principle is the computation and use of the bit probabilities derived from the symbol probabilities of Huffman codes. Thus, we obtain a joint source-channel decoding algorithm which takes advantage of this a priori knowledge. Even better performances are obtained when a turbo code-like iterative decoding is carried out. Compared to separate decoding systems, the gain in signal to noise ratio varies from 0.5 up to 1 dB with an added complexity which is relatively limited.