Performance Analysis of Soft Decoding Algorithms for Polar-Staircase Coding Scheme

Abstract

Polar codes are proved to be able to theoretically achieve the Shannon limit. However, the performance of polar codes with short code length is not well in practice. One widely used method to improve the short length codes is concatenation. Recently, staircase coding structure provides an efficient concatenation scheme for finite length block codes, which the component block code can concatenate itself to improve the coding performance. Thus, in this paper, we propose a high-rate polar-staircase coding scheme with systematic polar codes as the component codes. The polar-staircase coding scheme can enhance the unreliable parts of the polar codes through the concatenation. To achieve the asymptotic performance, which is mainly depending on the decoding algorithms, three soft decoding algorithms are analyzed for our polar-staircase coding. We first investigate the conventional belief propagation (BP) decoding and soft cancellation (SCAN) decoding. The performance of the two algorithms is not well in the short length regime. Then, we adopt and optimize a soft successive cancellation list (SSCL) decoding algorithm for the polar-staircase codes with the tradeoff between reliability and complexity. Simulations show that the SSCL decoding outperforms than the other soft decoding algorithms over the AWGN channels.