Turbo decoding with tail-biting trellises

Tail-biting codes are considered as component codes for parallel concatenated block codes. Based on the two-dimensional weight distribution of tail-biting codes, we calculate the minimum distance of the parallel concatenated code and give guidelines on how to choose good tail-biting component codes. We show how to encode tail-biting codes using systematic feedback encoders, which is an important design criterion. The performance of codes with different rate, length, and complexity using iterative (turbo) decoding is evaluated by simulation.