A Low-Complexity Improved Progressive Bit-Flipping Decoding for Polar Codes

The decoding performance of successive cancellation (SC) can be improved by correcting the error bits caused by channel noises. In order to identify and correct those error bits, we propose an improved progressive bit-flipping (IPBF) decoding algorithm. First, a more efficient method of constructing the set of error bit positions (EBPs) is proposed. It can significantly reduce the size of the set of EBPs, especially at medium to high signal to noise ratio (SNR). Second, a pruning technique of reducing the number of error bit-flipping combinations (EBFCs) is presented. In the case of ensuring that the decoding performance of PBF algorithm is not degraded, the decoding complexity is reduced as much as possible with the help of the pruning scheme. From the simulation results, compared to the conventional PBF algorithm, the proposed IPBF algorithm not only significantly reduces the average decoding complexity, but also has a slight improvement in decoding performance. At 2.0dB, the decoding complexity can be reduced by 63.6%, 87.5%, and 97.6% when ω is equal to 2, 3 and 4, respectively.