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IEEE Military Communications Conference (MILCOM)

Efficient Design of MET-LDPC Code Ensembles via Multinomial Parameter Optimization

Linh Nguyen, Tuy Tan Nguyen

Published Oct 6, 2025• 0 citations
Publisher

Abstract

Designing multi-edge type low-density parity-check (MET-LDPC) code ensembles that satisfy structural constraints while achieving near-capacity performance remains a challenging problem. Existing methods, including those based on differential evolution, have improved flexibility but still face limitations such as high computational cost and the need for manual configuration of edge patterns. We propose an optimization-based method that explores diverse, structurally feasible edge distribution candidates and optimizes node distributions via a constrained linear system formulation. A dual annealing optimizer is then applied to identify node profiles that maximize the decoding threshold. Evaluations on both the binary erasure channel and the binary-input additive white Gaussian noise channel across multiple code rates show that our method consistently produces ensembles with strong threshold performance and low edge complexity, highlighting its practicality and adaptability.

DOI
10.1109/milcom64451.2025.11310018

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Designing multi-edge type low-density parity-check (MET-LDPC) code ensembles that satisfy structural constraints while achieving near-capacity performance remains a challenging problem. Existing methods, including those based on differential evolution, have improved flexibility but still face limitations such as high computational cost and the need for manual configuration of edge patterns. We propose an optimization-based method that explores diverse, structurally feasible edge distribution candidates and optimizes node distributions via a constrained linear system formulation. A dual annealing optimizer is then applied to identify node profiles that maximize the decoding threshold. Evaluations on both the binary erasure channel and the binary-input additive white Gaussian noise channel across multiple code rates show that our method consistently produces ensembles with strong threshold performance and low edge complexity, highlighting its practicality and adaptability.
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The design of low-density parity-check (LDPC) code ensembles optimized for a finite number of decoder iterations is investigated. Our approach employs EXIT chart analysis and differential evolution to design such ensembles for the binary erasure channel and additive white Gaussian noise channel. The error rates of codes optimized for various numbers of decoder iterations are compared and it is seen that in the cases considered, the best performance for a given number of decoder iterations is achieved by codes which are optimized for this particular number. The design of generalized LDPC (GLDPC) codes is also considered, showing that these structures can offer better performance than LDPC codes for low-iteration-number designs. Finally, it is illustrated that LDPC codes which are optimized for a small number of iterations exhibit significant deviations in terms of degree distribution and weight enumerators with respect to LDPC codes returned by more conventional design tools.
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