Quad Ways for Polar Coded HARQ

Hybrid automatic repeat request provide wireless reliability while preserving significant efficiency in transmission, which is important for battery-operated low complexity applications such as IoT. The hybrid automatic repeat request system using polar codes as FEC, in combination with chase combining is simple to create. However, the HARQ-CC mechanisms often encounter challenges related to error rates and throughput performance. To improve error performance and reduce retransmissions, we developed four alternative HARQ-CC techniques. We utilize valuable information contained in received signals by introducing four LLR sequences to aid the decoder. The simulation results illustrate that the proposed techniques for creating new LLR's provide superior error performance and increased throughput efficiency while necessitating fewer retransmissions than simple HARQ-CC schemes.