A 5.79-Gb/s Energy-Efficient Multirate LDPC Codec Chip for IEEE 802.15.3c Applications Shao-Wei Yen, Shiang-Y u Hung, Chih-Lung Chen, Hsie-Chia Chang, Shyh-Jye Jou

Abstract

An LDPC codec chip supporting four code rates of IEEE 802.15.3c applications is presented. After utilizing row-based layered scheduling, the normalized min-sum (NMS) al- gorithm can reduce half of the iteration number while maintaining similar performance. According to the unique code structure of the parity-check matrix, a recon figurable 8/16/32-input sorter is designed to deal with LDPC codes in four different code rates. Both sorter input reallocation and pre-coded routing switch are proposed to alleviate routing complexity, leading to 64% input re- duction of multiplexers. In addition, an adder-accumulator-shift register (AASR) circuit is proposed for the LDPC encoder to reduce hardware complexity. After implemented in 65-nm 1P10M CMOS process, the proposed LDPC decoder chip can achieve maximum 5.79-Gb/s throughput with the hardware ef ficiency of 3.7 Gb/s mm and energy ef ficiency of 62.4 pJ/b, respectively.