A 115mW 1Gbps QC-LDPC decoder ASIC for WiMAX in 65nm CMOS

Structured quasi-cyclic low-density parity-check (QC-LDPC) code is a part of many emerging wireless communication standards, such as WiMAX, WiFi and WPAN. This paper presents a high parallel decoder architecture for the QC-LDPC codes and the corresponding decoder ASIC for WiMAX system. Through utilizing the proposed fully parallel layered scheduling architecture, the decoder chip saves 22.2% memory bits and takes 24~48 clock cycles per iteration for different code rates. It occupies 3.36 mm² in SMIC 65nm CMOS, and realizes 1Gbps (1056Mbps) throughput at 1.2V, 110MHz and 10 iterations with the power 115mW and power efficiency 10.9pJ/bit/iteration. The energy/bit/iteration reduces 63.6% in normalized comparison with the state-of-art publication.