High-Throughput Multi-Frame Decoding of QC-LDPC Codes with Modified Rejection-Based Minimum Finding
The key computation in the min-sum decoding algorithm of a Low-Density Parity-Check (LDPC) code is finding the first two minima and also the location of the first minimum among a set of messages passed from Variable Nodes (VNs) to Check Nodes (CNs) in a Tanner graph. In this paper, we propose a modified rejection-based scheme for this task which is able to find the one-hot sequence of the minimum location instead of its index. We show that this modification effectively reduces the complexity of min-sum decoding algorithm. Additionally, we reveal a pipelining potential in such a rejection- based architecture which facilitates the multi-frame decoding of LDPC codes and therefore results in improvement in decoding throughput with bearable hardware overhead. Synthesis in an industrial 28nm CMOS technology shows improved results in terms of throughput, power, and chip area.