Polar Codes for Soft Decode-and-Forward in HalfDuplex Relay Channels  

作　　者：Fangliao Yang Kai Niu Chao Dong Baoyu Tian 

机构地区：[1]Key Laboratory of Universal Wireless Communications,Ministry of Education,Beijing University of Posts and Telecommunications Beijing 100876,China

出　　处：《China Communications》2017年第8期22-32,共11页中国通信（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.61171099,No.61671080),Nokia Beijing Bell lab

摘　　要：Soft decode-and-forward(DF) can combine the advantages of both amplify-and-forward and hard DF in relay channels. In this paper, we propose a low-complexity soft DF scheme based on polar codes, which features two key techniques: a low-complexity cyclic redundancy check(CRC) aided list successive cancellation(CALSC) decoder and a soft information calculation method. At the relay node, a low-complexity CALSC decoder is designed to reduce the computational complexity by adjusting the list size according to the reliabilities of decoded bits. Based on the path probability metric of the CALSC decoder, we propose a method to compute the soft information of the decoded bits in CALSC. Simulation results show that our proposed scheme outperforms the soft DF based on low-density parity-check codes and the soft DF with belief propagation or soft cancellation decoder, especially in the case when the source-relay channel is at the high signal-to-ratio region.Soft decode-and-forward（DF） can combine the advantages of both amplify-and-forward and hard DF in relay channels. In this paper, we propose a low-complexity soft DF scheme based on polar codes, which features two key techniques： a low-complexity cyclic redundancy check（CRC） aided list successive cancellation（CALSC） decoder and a soft information calculation method. At the relay node, a low-complexity CALSC decoder is designed to reduce the computational complexity by adjusting the list size according to the reliabilities of decoded bits. Based on the path probability metric of the CALSC decoder, we propose a method to compute the soft information of the decoded bits in CALSC. Simulation results show that our proposed scheme outperforms the soft DF based on low-density parity-check codes and the soft DF with belief propagation or soft cancellation decoder, especially in the case when the source-relay channel is at the high signal-to-ratio region.

关 键 词：Decode and forward soft information relaying Polar codes relay channels 

分 类 号：TN911.22[电子电信—通信与信息系统]