On Finite Alphabet Iterative Decoding of LDPC Codes With High-Order Modulation
Xuan He, Kui Cai, Zhen Xing Mei · IEEE Communications Letters · 2019
This work aims to apply the mutual information-maximizing finite alphabet iterative decoding (MIM-FAID) method to decode low-density parity-check (LDPC) codes with high-order modulation. To this end, we propose an efficient model, through which our task becomes to design an MIM quantizer for a binary-input continuous memoryless channel (CMC) with log-likelihood ratios (LLRs) as the output. We then properly discretize the LLRs to convert the CMC to a discrete memoryless channel (DMC) such that we can obtain the MIM quantizer by using dynamic programming. Both theoretical analysis and simulation results verify the effectiveness of our proposed method.