An area efficient LDPC decoder using a reduced complexity min-sum algorithm

Hardware implementation of Low-Density Parity-Check (LDPC) decoders using conventional algorithms such as Sum-Product or Min-Sum requires large amount of hardware resources. A rather simplistic way to reduce hardware resources is to reduce the intrinsic message quantization. However this adversely affects the bit error rate (BER) performance significantly. In this paper, a resource efficient LDPC decoder based on a reduced complexity Min-Sum algorithm is presented. It reduces the inter-connect complexity by restricting the extrinsic message length to 2 bits and also simplifies the check node operation. Simulation at the algorithmic level shows that the proposed decoder achieves BER performance better than that of a 3-bit Min-Sum decoder, and therefore addresses the problem of massive BER performance degradation of a 2-bit Min-Sum decoder. The reduction in algorithmic complexity and further hardware optimization of the variable node leads to significant savings in hardware resources compared to 3-bit Min-Sum. An LDPC decoder with a code length of 1152 bits has been implemented on a Xilinx FPGA using the proposed algorithmic and hardware enhancements. With a 0.1 dB BER performance gain to that of 3-bit Min-Sum decoder, the proposed decoder saves about 18% of FPGA slices and provides a higher throughput. & 2011 Elsevier B.V. All rights reserved.