A Design of Hybrid Automatic Repeat Request Scheme Based on Systematic Polar Codes

Hybrid Automatic Repeat reQuest (HARQ) technology which is widely used in modern communication systems is a combination of ARQ technology and Forward Error Control (FEC) technology. Finding a high-performance FEC coding scheme has a great influence on the performance of HARQ system. Therefore, a new HARQ scheme based on systematic polar codes is designed in this paper. Besides, convolutional coded HARQ scheme, LDPC coded HARQ scheme and Turbo coded HARQ scheme are also simulated in our work as a comparison. In the simulation results, we mainly discuss the following three performance metrics of HARQ system: throughput efficiency, average number of transmission and frame error rate (FER). The simulation results show that, in the low Signal-to-Noise Ratio (SNR) regime, the throughput efficiency gap between the systematic polar coded HARQ scheme and the Turbo coded HARQ scheme is very small. More specifically, the proposed systematic polar coded HARQ scheme is only about 0.5dB away from the Turbo coded HARQ scheme in terms of the throughput efficiency. By the simulation of the average number of transmission, it shows that there is a slight gap between the systematic polar coded HARQ scheme and the Turbo coded HARQ scheme. Besides, as the SNR goes higher, the gap is getting smaller and smaller. The performance of FER of systematic polar coded HARQ scheme is slightly worse than that of Turbo coded HARQ scheme, but better than that of convolutional coded HARQ scheme and LDPC coded HARQ scheme.