A simple iteration stopping criterion for Turbo code

Turbo code becomes focus in coding research because of its excellent performance. But it needs many times of iteration in decoding, which results in long decoding time delay. To shorten the delay, iteration stopping is very important for turbo decoding without performance degradation. This paper proposes a simple iteration stopping criterion based on the number of bits whose likelihood ratio absolute values are larger than certain threshold, and gives simulations of average iteration times and decoding performance. The results of the simulations prove the algorithm’s validity.