Variable-length error-correcting codes

Variable-length error-correcting codes, suitable to perform joint source-channel coding, are presented. A maximum likelihood decoding algorithm for these codes is given. Some performance bounds are derived and it is shown that these codes are similar to convolutional codes. The free distance of these codes is defined and it is shown that it is the most important parameter that determines their performance at high E_b/N₀. It is shown that the performance of these codes can be better than a standard cascade of a Huffman code followed by a BCH code with the same code parameters