Adaptive Reweighted Freezing Belief Propagation Decoding for Polar Codes
Xiaojin Guo, ZHANG Jingtao
Abstract
To address the challenges of high computational redundancy, slow convergence speed, and limited decoding performance in Belief Propagation (BP) decoding of polar codes, this paper proposes an Adaptive Reweighted Freezing (ARF) BP decoding algorithm. This algorithm introduces an adaptive reweighting mechanism to regulate the weights of message updates, thereby accelerating the convergence of the decoding process. Furthermore, it implements a freezing judgment strategy for converged nodes within the factor graph to eliminate redundant calculations. Simulation results demonstrate that, in the low Signal-to-Noise Ratio (SNR) region, the ARF-BP algorithm achieves a performance gain of approximately 1.1 dB compared to the traditional BP decoding algorithm. Moreover, compared to BP decoding with the G-matrix early stopping criterion, it reduces the average number of iterations by about 64% and effectively freezes approximately 20% of the factor graph nodes. Featuring low latency and low power consumption, this algorithm is well-suited for critical scenarios such as 5G massive Machine Type Communications and Ultra-Reliable Low-Latency Communications.