A 58.6/91.3 pJ/b Dual-Mode Belief-Propagation Decoder for LDPC and Polar Codes in the 5G Communications Standard

This letter presents the first belief propagation (BP) decoder IC implementation for the two forward error correction (FEC) codes in the 5G communication standard. The LDPC mode supports 5G BG2 with 128 lifting size, while the polar mode supports code length
$N = 1024$
. The 40-nm CMOS chip features BP module sharing, memory reuse, check node unit design, forwarding and layer pipelining, and dataflow rearrangement. Compared to two single-mode decoders, this dual-mode decoder saved 37% in the overall die area, 32% in the computation circuit area, and 41% in the memory area. The chip delivers throughputs of 2.38 and 1.85 Gb/s from 0.9-V Vdd with energy efficiencies of 58.6 and 91.3 pJ/b in the LDPC mode and the polar mode, respectively.