Improved list decoding of tail-biting convolutional codes

The novel decoding algorithm for the list decoding of tail-biting convolutional codes is described. The main idea is first to estimate the most reliable state from all state spaces for transmitted codeword by using a Soft Input Soft Output decoder, and then to perform the list Viterbi decoding algorithm from this state around the circular tail-biting trellis. For the LTE standard concatenated coding scheme this algorithm provides block error rate performance that is almost the same as for the optimal brute-force list decoding algorithm with significantly less complexity (about 11 times) for list size L=4.