Low-Latency SCL Bit-Flipping Decoding of Polar Codes

Abstract: Bit flipping can be used as a postprocessing technique to further improve the performance for successive cancellation list (SCL) decoding of polar codes. However, the number of bit-flipping trials could increase the decoding latency significantly, which is not welcome in practice. In this paper, we propose a low latency SCL bit flipping decoding scheme, which is restricted to just single round of post-processing. The use of multiple votes for a more accurate estimation of path survival probability is proposed to locate the first error event of SCL decoding. Simulations show the sound improvement compared to the existing SCL bit-flipping decoding methods.