Design of a layered LDPC decoder

Haibin Zhang, Jia Zhu, Huifeng Shi +1 more

Layered approximately regular (LAR) low-density parity-check (LDPC) codes are proposed, with which one single pair of encoder and decoder support various code lengths and code rates. The parity check matrices of LAR-LDPC codes have a "layer-block-cell" structure with some additional constraints. An encoder architecture is then designed for LAR-LDPC codes, by making two improvements to the Richardson-Urbanke approach: the forward substitution operation is entirely removed and the dense-matrix-vector multiplication is handled using feedback shift-registers. A partially parallel decoder architecture is also designed for LAR-LDPC codes, where a layered modified min-sum decoding algorithm is used to trade off among complexity, speed, and performance. More importantly, the interconnection network, which is inevitable for partially parallel decoders, has much lower hardware complexity compared with that for general LDPC codes. Both the encoder and decoder architectures are highly flexible in code length and code rate.

Frédéric Guillou, Emmanuel Boutillon, Jacky Tousch +1 more

Zhiqiang Cui, Zhongfeng Wang

In this paper, we propose an extended layered decoding approach for low density parity check (LDPC) codes. Compared to conventional layered decoding algorithms, the proposed approach has no constraint in the column weight of each layer. Hence, it enables more flexibility in high-throughput LDPC decoder design with layered decoding. Simulations on structured and random LDPC codes show that the proposed decoding method achieves significantly faster convergence and slightly better error correction performance than the conventional two phase massage passing sum-product algorithm. We also propose an efficient highly parallel decoder architecture for generic quasi-cyclic LDPC codes to facilitate the practical application of the proposed decoding scheme.

Wang, Dong, Mingke +5 more

Min Jang, Kyeongyeon Kim, Seho Myung +3 more

This paper presents an analytically designed layered decoding algorithm for quasi-cyclic low-density parity-check (QC-LDPC) codes in the 5th Generation (5G) New Radio (NR) mobile communication system. First, a layered density evolution (DE) based on reciprocal channel approximation (RCA) is newly developed to accurately reflect the layered decoding operation in the decoder design. Using this technique, a single nested sequence is optimized in a greedy way to configure the processing order for any given number of layers. The error-correction performance is improved by up to 0.15 dB, while the number of iterations is reduced by about one simultaneously.

Amrit Pal Singh, Sanjay Sharma