Hybrid BP/Fast-SSCF Polar Decoder for 5G Beyond Consumer Communications

To achieve high correction performance and low decoding latency, this paper initially presents a hybrid Belief Propagation (BP) and Fast-Simplified-Successive-Cancellation-Flip (Fast-SSCF) decoding for polar-coded consumer communications. Different to conventional decoding, the proposed BP/Fast-SSCF algorithm first employs BP decoding to leverage its high throughput and low latency benefits. It seamlessly transitions to low-complexity Fast-SSCF decoding to enhance error-correction performance if BP decoding fails. This strategy achieves high error-correction performance with reduced average decoding latency and computational complexity. Compared with the standalone BP and standalone Fast-SSCF decoding, the hybrid decoding achieves 1.1 dB and 0.25 dB coding gains at frame error rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10{^{\text {-4}}}$ </tex-math></inline-formula>. Subsequently, a hybrid polar decoder is proposed with a hardware-sharing decoding core and buffer performing the proposed hybrid BP/Fast-SSCF decoding. Implemented using TSMC 40-nm CMOS process technology, the proposed hybrid decoder achieves a synthesis core area of 1.95 mm2, a throughput of 3.82 Gbps, a latency of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.26~\mu $ </tex-math></inline-formula>s, and a 7.13% reduction in area. The proposed decoder demonstrates reduced average decoding latency, superior average throughput, and comparable error correction ability compared with other designs, marking the first triple-mode polar decoder design.