Multi-Relay-Enhanced Dual-Hop Terahertz Communication: A Performance Analysis

In this paper, we examine the performance of a dual-hop terahertz (THz) wireless communication system based on multiple decode-and-forward (DF) relays. The functioning of the THz system is primarily influenced by path loss, fading, and pointing errors. The fading in the THz link is modeled using the α-μ model, and by considering the end-to-end instantaneous signal-to-noise ratio (SNR), we employ the opportunistic relay selection (ORS) technique to select the best relay for transmission in the second hop. Further, we derive the closed-form expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the end-to-end instantaneous SNR. Utilizing these statistical formulations, we evaluate the performance metrics such as outage probability, average symbol error rate (SER), and ergodic capacity. Asymptotic analysis is also conducted to determine the system's diversity gain and get additional insights into its performance. Finally, Monte-Carlo simulations are performed to validate the derived analytical expressions.