FPGA architecture of multi-codeword LDPC decoder with efficient BRAM utilization

Abstract

Implementation of Quasi-Cyclic (QC) Low Density Parity-Check (LDPC) decoder on FPGA devices has shown great interest in both wireless communication, as well as error correction for Flash memories. This paper presents an FPGA flooded LDPC decoder which uses multiple codeword processing for efficient memory utilization. It is based on a partially parallel implementation, which relies on memory blocks for message passing between the processing units. We obtain efficient memory utilization by packing multiple messages corresponding to multiple codewords into the same Block RAM word. The increase in throughput is linear with the number of processed codewords. The proposed LDPC decoder can process up to 9 codewords in parallel, for 4-bit message quantization, or up to 12 codewords, for 3-bit message quantization, without introducing significant memory overhead.