Performance Analysis of UAV Assisted Mobile Communications in THz Channel

Abstract

The huge available bandwidth in Terahertz (THz) frequency band is recently contemplated to achieve high data rate wireless communications. Consequently, THz communications are attractive candidates to fulfill the continuous ever-increasing requirements of future wireless networks. Numerous beyond 5G applications are highly considered for those systems such as high capacity backhaul, enhanced hotspot booths as well as short-range device-to-device (D2D) communications. Wireless communications systems that deploy unmanned aerial vehicles (UAVs) promise to achieve cost-effective wireless connectivity for devices without any need to pay for infrastructure coverage. When compared to terrestrial communications, wireless systems with UAVs are generally faster and more flexible to deploy or reconfigure. In addition, systems deploying UAVs are likely to have much better communication channels due to their high mobility capabilities. Accordingly, the presence of short-range line-of-sight (LOS) links prevail. In this paper, we consider a single-cell cellular network with a UAV deployed as a decode-and-forward (DF) relay in the full-duplex (FD) mode in order to assist a base station (BS) and extend its coverage over THz channel. A joint power allocation and trajectory optimization scheme that minimizes 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 THz frequency band. Furthermore, the optimum powers of the MD and the UAV that maximize the achievable rate at the BS are obtained. The performance of the proposed schemes is compared with the fixed power allocation schemes which distribute the power equally among users. Numerical results show that the outage probability and the achievable rate at the BS using the proposed schemes are remarkably superior compared to the fixed power allocation schemes.

Outage performance analysis of RIS-assisted UAV wireless systems under disorientation and misalignment

“…As a result, the adverse effects of UAV disorientation and/or misalignment of the RIS-UAV beam have been neglected. However, as we move toward next-generation wireless systems, both the operating frequency and thus the directionality of links are expected to increase [13], [34]- [36]. Therefore, even small disorientations and/or misalignments may adversely affect the performance of the RIS-assisted UAV wireless system [37], [38].…”

Performance Analysis of UAVs System in THz-Band Communications under Different Fading Channels

“…It's also important to note that the utilization of THz band UAVto-UAV communication allows for almost real-time processing, upload-ing, and downloading between two closeproximity user devices [18]. UAV-to-UAV com-munications in the THz frequency range are taken into consideration in a number of re-search papers from the literature [19][20][21]. According to the discussion above, it is clear that researchers do not prioritize analyzing the model that combines THz and UAV technologies' outage probability, average capacity, and bit error rate under various fading channels.…”

Identification of Terahertz Link Modulation in Atmospheric Weather Conditions

“…However, wireless links at terahertz frequencies are more susceptible to absorption and to scattering effects by atmospheric weather and suffer more serious deterioration in link performance [4,5]. In order to offset this influence, methods based on high-power antennae [6], signal repeaters [7], and adaptive signal processing [8] have been proposed and proved to be effective. Modulation identification, as an important signal processing method [9], can recognize different link modulation formats based on the weight matrix of signal features and help to decrease the response time of the entire system finally.…”