Serial FFT-BP LDPC decoding based on unsymmetrical message transmission

A low complexity serial Fast Fourier Transform Belief Propagation (FFT-BP) algorithm for decoding non-binary low-density parity-check (LDPC) codes use unsymmetrical message transmission scheme between bit nodes and check nodes is presented. Before each step of iteration, every symbol node´s reliability was evaluated based on high reliable check number and pseudo a posterior probability (APP). The variable nodes with high reliability will just send messages to its neighbour and avoid the messages from them. Compared to the previous traditional message transmission method, it can use the messages adaptively, and therefore provide better decoding quality and computation complexity reduction. Simulations show that the proposed method could improve performance and reduce complexity at the same time compared with the conventional FFT-BP decoding algorithm.