Performance evaluation of turbo-codes

Parallel concatenated coding schemes employing convolutional codes as constituent codes linked by an interleaver have been proposed in the literature as "turbo codes". They yield very good performance in connection with simple suboptimum decoding algorithms. The authors derive an analytical upper bound to the average performance of such coding schemes, which is independent of the interleaver used and shows the influence of the interleaver length on the code performance. >