Abstarct: we use an UAV as a DF relay in 5th generation to convey information from transmitter to recievers.The objective of this system is maximizing transmitted information from source to two destinations. Transmitting signal is done in LoS mode and also in NLoS mod with respect to LoS and NLoS probability. The transmitter uses a battery to transmit information to relay and UAV is equipped with solar panels using which it harvests the energy to transmit information to recievers. UAV uses non orthogonal multiple access method and physical laxyer security technique to send information to recievers simultaneously. This thesis uses iterative algorithms baxsed on approximation methods. Simulation of this thesis is done with CVX. Results of this thesis show that the throughput decreases as the altitude of UAV increases and the throughput increases as the amount of energy harvesting increase and the throughput decreases as the speed of UAV increases. We also show that throughput baxsed on NOMA method is larger than throughput baxsed on OMA method.