SC-Fano Decoding of Polar Codes

Abstract

For finite-length polar codes, the standard successive cancellation (SC) decoding has been improved, such as SC-List (SCL), SC-Stack (SCS), and SC-Flip (SCF) decodings. In this paper, we present an alternative improvement of SC decoding by incorporating the Fano sequential decoding into SC decoding. This is referred to as SC-Fano decoding. Specifically, it can address the major drawback of SC decoding by enabling moving-backward when the reliability of an on-going path is not good enough. The SCS and SC-Fano decodings can be viewed as the sequential decoding for polar codes. In addition, for cyclic-redundancy-check (CRC) concatenated polar codes, we enhance SC-Fano decoding by leveraging the bit-flipping idea of SCF decoding. The simulation results demonstrate that the proposed SC-Fano decoding can provide better performance-complexity tradeoff than the existing decoding methods.

Keywords

• Polar codes
• successive-cancellation (SC) decoding
• sequential decoding