Analog Iterative LDPC Decoder Based on Margin Propagation

A margin propagation (MP) algorithm that can be used for implementing analog decoders for low-density parity check (LDPC) codes is presented. Unlike conventional sum-product analog decoders that rely on translinear operation of transistors, MP decoders use addition, subtraction and threshold operations, and therefore can be mapped onto different analog circuit topologies (current-mode, charge-mode, or nonelectronic circuits). This brief describes salient properties of the MP decoding algorithm and compares its performance to the sum-product and the min-sum (MS) decoding algorithms. Simulation results demonstrate that MP based LDPC decoders achieve nearly an identical bit error rate performance as their sum-product counterparts and achieve superior performance as compared to the MS decoding algorithm. Results presented in this brief also demonstrate that, when messages in LDPC decoding are corrupted by additive noise, the MP decoding algorithm delivers superior performance compared to its sum-product and MS counterparts.