Iterative chase-2 algorithm using threshold for block turbo codes decoding design

In this paper, we introduce an approach to get better performance of block turbo codes (BTCs). We use threshold to limit the search for the maximum-likelihood codeword. Consequently, by using chase-2 algorithm, Euclidean distance will be calculated from smaller group of candidate codeword, and we can calculate reliability and extrinsic information easier and faster. So a faster iterative decoding process is achieved to take these extra threshold calculations into chase-2 algorithm for BTCs. We evaluate the performance of this decoding process on additive white Gaussian noise (AWGN) channel. And decoding complexity reduces a lot over the standard iterative decoding methods. We also add this idea into the hardware design of BTCs decoder. It also shows good reduction for number of operations.