Design of systematic polar coded selective-IR hybrid ARQ transmission for IoT

In this paper, hybrid automatic repeat request schemes with selective incremental redundancy (SIR-HARQ) are designed for systematic polar codes (SPC), which could be well implemented in the low-power consumption and low-complexity applications like Internet of Things (IoT). Without puncturing, first scheme is searching the optimal redundant bits to transmit in the last remaining redundancy range progressively. Secondly, we propose a simpler design of transmitting the redundancy incrementally in the priority of importance of parity bits. Simulations indicate that with SPC length of 128 bits, both proposed schemes with SIR can obtain a significant throughput gain compared with IEEE standard for wireless body area networks and the state-of-the-art systematic polar coded IR-HARQ in AWGN channel, without high increase of complexity. Additionally, the proposed SIR also performs much better than the non-SIR scheme in Rayleigh fading channel.