Efficient parity bit estimation for turbo codes

In this paper a novel and efficient method for estimating parity bits in a turbo decoder is presented. The main idea is as follows. First we estimate only information bits in a traditional iterative manner. After the information bits are assumed to be detected correctly or the maximum number of information bit decoding iterations is achieved, we forward all soft information to soft parity estimation blocks. In this way we can improve the parity bit estimation performance and decrease the decoding complexity, compared to the traditional scheme where information and parity bits are jointly estimated in the same iterative loop.