Outage Analysis for Automatic Repeat Request Mechanism Assisted Backscatter Communication Systems

Backscatter communication emerges as a green communication technology which can provide passive IoT tags with the energy required for communication with each other through energy harvesting. This paper investigates the outage performance of an automatic repeat request mechanism assisted backscatter communication system (ARQ-BCS). Firstly, considering the energy constraints at the backscatter tag, we obtain in detail the decoding signal-to-noise ratio of the ARQ-BCS and define the outage probability of this system. Subsequently, according to the defined outage probability, we derive a closed-form expression for the outage probability based on ARQ-BCS and compute the average number of retransmissions for this system. We validate the accuracy of the above theoretical analyses from simulations and investigate the effects of the system parameters on the outage performance. The results show that the integration of the automatic repeat request mechanism significantly improves the performance of the backscatter communication system.