Enhanced Belief Propagation Decoder for 5G Polar Codes with Bit-Flipping

Due to its parallel propagation property, the belief propagation (BP) polar decoding can achieve high throughput and has drawn increasing attention. However, the BP decoding is not comparable with the successive cancellation list (SCL) decoding in terms of the error correction performance. In this brief, two BP flip (BPF) decoding algorithms are proposed. Compared with the existing BPF decoding, the generalized BPF (GBPF) decoding identifies error-prone bits more efficiently with a redefinition of bit-flipping. Furthermore, the GBPF decoding is optimized by decreasing the searching range by half, leading to the enhanced BP flip (EBPF) decoding with reduced complexity and improved performance for 5G polar codes. The hardware architecture is provided and implemented using SMIC 65nm CMOS technology. The results show that, compared with the state-of-the-art SC flip decoders, the proposed EBPF decoder exhibits 30% throughput improvement under comparable error correction performance.