Low-Complexity Hybrid ARQ Scheme for Polar Codes with Higher-Order Modulation

• Published in: GLOBECOM 2017 - 2017 IEEE Global Communications Conference pp. 1 - 6
• Main Authors: Kuangda Tian, Rongke Liu, Vardy, Alexander, Runxin Wang
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2017
• Subjects: AWGN channels; Complexity theory; Decoding; Error probability; Modulation; Receivers; Throughput
• DOI: 10.1109/GLOCOM.2017.8254939

Combining the polar coded hybrid automatic repeat request (HARQ) with higher-order modulation has been proposed recently. To further improve the throughput of HARQ, a novel polar coded HARQ cheme with higher-order modulation is proposed. Wherein the proposed HARQ scheme, the unequal rror protection (UEP), caused by bit-mapping, in bit- interleaved polar coded modulation (BIPCM) is considered. Based on UEP, a non-linear integer programming (NLIP) problem is constructed to determine the optimal retransmitted sequence. Furthermore, a low-complexity suboptimal algorithm is proposed to solve the resulting NLIP problem. Simulation results show that the throughput of the proposed HARQ scheme outperforms the existing polar coded HARQ for higher-order modulation; in particular, our scheme easily accommodates arbitrarily puncturing methods. This makes it possible to use recently proposed puncturing methods for polar codes to further improve the performance of our HARQ scheme.