Performance improvement of turbo codes by error range search method in Rayleigh fading channel

Turbo codes has better performance as the number of iteration and interleaver´s size increases. This requires the reduction of the delay and computational complexity for decoding the input data. We propose an efficient method of decoding turbo codes that can greatly reduce the iteration number with very low-complexity. The MAP algorithm depends on the adjacent bits or received symbols. Therefore, to improve the performance of the MAP algorithm, the reliability of adjacent received symbols has to be guaranteed. Thus, we propose a simple ERS (error range search) method for the reliability of the received symbols in MAP algorithm. Using the proposed ERS method, we analyze the performance of the ERS/MAP algorithm and ERS/turbo decoder in a Rayleigh fading channel