Transmitter

Quantum mechanics

Control (management)

Social psychology

Signal-to-noise ratio (imaging)

Relay

Telecommunications

Power (physics)

Computer science

Mathematical optimization

Beamforming

Power budget

Physics

Psychology

Mathematics

Power control

Relaxation (psychology)

Artificial intelligence

Transmitter power output

Channel (broadcasting)

Control theory (sociology)

Optimization problem

IEEE Transactions on Vehicular Technology

This paper investigates an unmanned aerial vehicle (UAV) enabled full-duplex relaying system. By assuming that the UAV follows a circular trajectory and applies decode-and-forward relaying strategy, we study the joint design of beamforming and power allocation to maximize the instantaneous data rate, under both the individual and the sum power constraints over the source and relay nodes. As the problem is non-convex, we propose an efficient sub-optimal solution based on block-coordinate descent method by decomposing the problem into two sub-problems: a beamforming optimization sub-problem with given power allocation and a power allocation sub-problem with fixed beamforming. For the beamforming design sub-problem, the optimal solution is obtained based on the semi-definite relaxation technique. For the power allocation sub-problem, the optimal solution is obtained in closed form. Then, the closed-form cumulative distribution function and outage probability expressions for sub-optimal beamforming with both uniform power allocation and optimal power allocation are derived. In addition, simple and informative high signal-to-noise ratio (SNR) approximations for outage probability expressions are presented to gain insights. Finally, the optimal flying altitude that minimizes the average outage probability is obtained via one-dimensional search.

Joint Beamforming and Power Allocation for UAV-Enabled Full-Duplex Relay