Improved iterative decoding of LDPC codes from the IEEE WiMAX standard

Multiple-bases belief-propagation is a parallel decoding setup which allows for improved decoding performance when compared to standard belief-propagation. Originally designed for decoding of high-density parity-check codes in an iterative manner, this method also shows good decoding results for well-designed low-density parity-check codes when signaling over the AWGN channel. We show the applicability of this scheme to channel codes defined in the IEEE WiMAX standard. It is challenging to find sets of well-performing parity-check matrices for these codes, all of them differing from each other. We propose an algorithm which makes use of the special structure of an underlying base matrix to accomplish this task. The results are compared to codes constructed by the progressive edge-growth algorithm and to bounds from information theory.