Short packet communications for cooperative UAV-NOMA-based IoT systems with SIC imperfections

Abstract

In this paper, we investigate a non-orthogonal multiple access (NOMA)-enabled unmanned aerial vehicle (UAV)-aided Internet of Things (IoT) system with short packet communications over Nakagami-m fading channel. In this system, the multi-antennas UAV plays role as a relay to assist communication between two IoT device pairs, which results in two NOMA stages implemented at the UAV for both uplink and downlink transmissions. To evaluate the performance of the system, we first determine the cumulative distribution function of the received signal-to-interference-plus-noise ratio, base on this, the average end-to-end (e2e) block-error rates (BLERs) under the presence of perfect and imperfect successive interference cancellation (SIC) procedure are deduced. Aiming to reveals insights into system designs, we have further investigate the system performance at high signal-to-noise ratio regime, where destination’s diversity gain is obtained. Additionally, the effects of the system parameters such as the transmit power, the power allocation coefficient, altitude and speed fly of the UAV, and the coefficients of channel model on the system performance are studied. The results demonstrate that increase in the number of antennas at the UAV improves significantly the performance of the users in terms of the average e2e BLERs of the users. Particularly, Monte Carlo simulations confirm the derived theoretical analysis.