Outage Probability Analysis of UAV Assisted Mobile Communications in THz Channel

THz Communications are attractive candidate for providing ultra high data rate required by 5G and beyond. Unmanned Aerial Vehicle (UAV) is an emerging facility which can be used to assist wireless communications. In this paper, we consider a single-cell cellular network with a UAV that works as a decode-and-forward (DF) relay in full-duplex (FD) mode to assist a base station (BS) and extend its coverage over THz channel. A number of underlay device-to-device (D2D) pairs that communicate with each other and reuse the cellular resources is also considered. The outage probability of the link between the BS and a mobile device (MD) is derived in the presence of the interference of the D2D devices that share the same frequency band. The transmit powers of the MD and the UAV that minimize the outage probability are derived and compared with that of fixed power allocation. Numerical results show that the outage probability obtained using the proposed optimum power allocation scheme is decreased by 20% from the outage probability obtained using fixed power allocation scheme.