Fast-convergence architectures and low-complexity algorithms for LDPC decoding

Jin Xie, Liuguo Yin, Ning Ge +1 more

Abstract: In this paper, a fast-convergence algorithm is proposed for the decoding of low-density parity-check (LDPC) codes. By putting more weight on the message update from check node to variable node in current iteration, the proposed method speeds up the decoding significantly. Simulation results show that compared with the standard layered min-sum decoding algorithm, the proposed scheme may reduce about 1/6 iteration numbers for LDPC codes used in DVB-S2, with hardware complexity overhead less than 2%. Key–Words: LDPC code, fast convergence decoding algorithm, layered decoding, min-sum algorithm, hardware implementation 1

Amrit Pal Singh, Sanjay Sharma

Shiva Kumar Planjery, Bane V. Vasic, David Declercq +1 more

Z. Cui, Zhirui Wang Zhirui Wang, Xiaofang Zhang

Layered decoding is well appreciated in low-density parity-check (LDPC) decoder implementation since it can achieve effectively high decoding throughput with low computation complexity. This work, for the first time, addresses low-complexity column-layered decoding schemes and very-large-scale integration (VLSI) architectures for multi-Gb/s applications. At first, the min-sum algorithm is incorporated into the column-layered decoding. Then algorithmic transformations and judicious approximations are explored to minimise the overall computation complexity. Compared to the original column-layered decoding, the new approach can reduce the computation complexity in check node processing for high-rate LDPC codes by up to 90% while maintaining the fast convergence speed of layered decoding. Furthermore, a relaxed pipelining scheme is presented to enable very high clock speed for VLSI implementation. Equipped with these new techniques, an efficient decoder architecture for quasi-cyclic LDPC codes is developed and implemented with 0.13 µm VLSI implementation technology. It is shown that a decoding throughput of nearly 4 Gb/s at a maximum of 10 iterations can be achieved for a (4096, 3584) LDPC code. Hence, this work has facilitated practical applications of column-layered decoding and particularly made it very attractive in high-speed, high-rate LDPC decoder implementation.

Ho-Il Kim

Lin Zhi-guo

We consider the convergence problem of the conventional decoding scheme of Low-Density Parity-Check(LDPC) codes over Additive White Gaussian Noise(AWGN) channels.In this correspondence,we propose a fast convergence decoding scheme based on quantization,which is a comprehensive method of taking advantage of the Layered Belief Propagation(LBP) algorithm,the Offset Min-Sum(OMS) algorithm and the quantization method.Compared to the conventional quantized Min-Sum algorithm,the proposed scheme efficiently reduces the decoding complexity and significantly accelerates the decoding convergence with no additional performance loss.We show that with simulations.