The trellis evolution algorithm for nonlinear block codes

An algorithm is proposed to search the desired trellis structure for block codes. It consists of a sequence of vertex mergings (evolutions) on a code graph. Any sequence of evolutions will result in the BCJR trellis (McEliece 1996) for linear codes. By searching all possible evolution paths, the desired trellis structure for nonlinear codes can be obtained. Vertex mergeability is examined to reduce the number of searches to a minimum, and lead to the progressive vertex set partition algorithm.