Zongwang Li

A Simplified Min-Sum Decoding Algorithm for Non-Binary LDPC Codes

Non-binary low-density parity-check codes are robust to various channel impairments. However, based on the existing decoding algorithms, the decoder implementations are expensive because of their excessive computational complexity and memory usage. Based on the combinatorial optimization, we present an approximation method for the check node processing. The simulation results demonstrate that our scheme has small performance loss over the additive white Gaussian noise channel and independent Rayleigh fading channel. Furthermore, the proposed reduced-complexity realization provides significant savings on hardware, so it yields a good performance-complexity tradeoff and can be efficiently implemented.

A new min-sum based decoding algorithm for non-binary LDPC codes

Non-binary low-density parity-check (NB-LDPC) codes are robust to various channel impairments. In this paper, we present a new decoding algorithm for the NB-LDPC decoder that is based on the q-ary min-sum algorithm (QMSA). The new one modifies the check node (CN) computations of the QMSA into two steps. By reorganizing the message entries and providing the most likely symbol, a compressed intermediate message can be easily obtained and stored, from which the check-to-variable messages can be computed with a look-up table. Thus the decoder architecture can have a straightforward design for the CN with reduced complexity and memory requirements. Besides, the simulation results demonstrate that the proposed algorithm has negligible performance loss compared to the QMSA over AWGN channel.