A New Efficient Adaptive Normalized Min-Sum Decoder for Irregular LDPC Codes in OFDM

In this letter a new decoding algorithm based on the adaptive normalized min-sum algorithm and the joint decoding algorithm is proposed for irregular low density parity check codes in OFDM system. The new proposed algorithm changes the update rule of the normalized min-sum algorithm to improve its performance. Also, instead of having separate horizontal and vertical processing phases in decoding algorithm, the vertical phase is merged with the horizontal phase. The proposed decoder improves the performance in waterfall and error floor regions. The convergence speed of the proposed algorithm is much faster. Therefore, the proposed decoder is able to converge to its final bit error rate in fewer iterations.