Reduction of computational complexity in two-step SOVA decoder for turbo code

A new two-step soft output Viterbi algorithm (SOVA) for turbo decoder with reduced decoding complexity is proposed and analyzed in this paper. Due to the algebraic structure of the proposed scheme, state and branch metrics can be obtained with parallel processing of matrix arithmetic. As a result, the number of multiplications to calculate state metrics of each stage can be decreased tremendously. Therefore, it can be expected that the proposed algebraic two-step SOVA decoder is suitable for applications in future mobile communication systems in which less computational complexity is essential