An Adaptive Ordered Shifted-Pruning List Decoder for Polar Codes

Abstract

The polar code has been selected as a channel coding solution for the control channel of 5th generation wireless systems (5G). Compared with the conventional cyclic-redundancy-check-aided successive cancellation list (CA-SCL) decoder for polar codes, the improved CA-SCL decoders not only can reduce the computational complexity but also keep similar block error rate (BLER). To further reduce the computational complexity and improve the BLER performance of the CA-SCL decoder, we propose an adaptive ordered shifted-pruning list (ADOSPL) decoder. The proposed method employs the ordered critical set (OCS) to improve the BLER performance and uses adaptive search width to reduce the computational complexity. Simulation results reveal that the ADOSPL decoder can significantly reduce 94.75% computational complexity compared with the CA-SCL decoder and improve the BLER performance gain up to 0.25dB for a polar code (512, 272) when the search width is 32. Moreover, lower computational complexity brings lower energy consumption and lower decoding delay in actual communication systems.

Keywords

• Channel coding
• polar code
• list decoder
• adaptive coding
• ordered shifted pruning