# SC-Fano Decoding of Polar Codes

## TL;DR

This paper introduces SC-Fano decoding, a novel polar code decoding algorithm that improves reliability and performance over standard SC decoding while maintaining low memory use, suitable for hardware implementation.

## Contribution

The paper proposes SC-Fano decoding, integrating Fano sequential decoding into SC decoding, offering better error correction with lower memory requirements compared to existing methods.

## Key findings

- SC-Fano decoding improves error performance over standard SC decoding.
- It achieves similar performance to SCL decoding with lower complexity.
- The method requires less memory, making it suitable for hardware implementation.

## Abstract

In this paper, we present a novel decoding algorithm of a polar code, named SC-Fano decoding, by appropriately incorporating the Fano sequential decoding into the standard successive-cancellation (SC) decoding. The proposed SC-Fano decoding follows the basic procedures of SC decoding with an additional operation to evaluate the reliability (or belief) of a current partial path. Specifically, at every decoding stage, it decides whether to move forward along a current path or move backward to find a more likelihood path. In this way, SC-Fano decoding can address the inherent drawback of SC decoding such as one wrong-decision will surely lead to a wrong codeword. Compared with the other improvements of SC decoding as SC-List (SCL) and SC-Stack (SCS) decodings, SC-Fano decoding has much lower memory requirement and thus is more suitable for hardware implementations. Also, SC- Fano decoding can be viewed as an efficient implementation of SC-Flip (SCF) decoding without the cost of cyclic-redundancy-code (CRC). Simulation results show that the proposed SC-Fano decoding significantly enhances the performance of SC decoding with a similar complexity as well as achieves the performance of SCL decoding with a lower complexity.