Paper Info
Title
Improved Belief Propagation Polar Decoders With Bit-Flipping Algorithms
Abstract
Since the inherent serial nature of successive cancellation list (SCL) decoding results in a long latency, belief propagation (BP) decoding for polar codes has drawn attention for high-throughput applications. However, its error correction performance is inferior to that of SCL decoding. Therefore, the bit-flipping strategy has been recently applied to BP decoding, which can approach the SCL decoding performance through multiple additional decoding attempts. The original BP flip (BPF) decoding suffers from an inaccurate identification of erroneous bits by a fixed flip set (FS), which has been improved by the generalized BPF (GBPF) decoding. In this article, the GBPF decoding is extended to support multiple bits being flipped in one decoding attempt. In addition, for two types of decoding errors: detected errors and undetected errors, we propose two novel methods to more effectively identify erroneous bits. For detected errors, the concept of loop sets is defined and a loopbased identification method is introduced based on the study of error patterns of BP decoding. On the other hand, a method to generate a more accurate fixed FS is proposed for undetected errors, which considers the bit error distribution under BP decoding. Combining the two methods, the GBPF with merged sets (GBPF-MS) decoding can achieve the SCL-8 performance and outperforms the state-of-the-art BPF, BP list, and SC flip (SCF) decoding, for polar codes with length 1024 and information rate 1/2. Implemented by 40nm CMOS technology, the proposed GBPF-MS decoder with ten flips exhibits an average throughput of 4.19 Gbps at 2.5 dB, which is 1.6× and 1.72× faster than the state-of-the-art SCL-4 and SCF decoders, respectively.
Year
DOI
Venue
2020
10.1109/TCOMM.2020.3017656
IEEE Transactions on Communications
Keywords
DocType
Volume
Polar codes,belief propagation (BP) decoding,bit-flipping,error patterns,flip set
Journal
68
Issue
ISSN
Citations 
11
0090-6778
3
PageRank 
References 
Authors
0.42
0
7
Name
Order
Citations
PageRank
Yifei Shen1155.36
Wenqing Song2153.35
Houren Ji371.86
Yuqing Ren481.87
Chao Ji530.42
xiaohu you62529272.49
Chuan Zhang710013.67