Exponential error bounds and decoding complexity for block concatenated codes with tail biting trellis inner codes

Tail biting trellis codes and block concatenated codes are discussed from random coding arguments. An error exponent and decoding complexity for tail biting random trellis codes are shown. We then propose a block concatenated code constructed by a tail biting trellis inner code and derive an error exponent and decoding complexity for the proposed code. The results obtained by the proposed code show that we can attain a larger error exponent at all rates except for low rates with the same decoding complexity compared with the original concatenated code.