Enhanced Performance in Mixed THz and Multi-Antenna RF Systems With MRC Diversity

Abstract

This letter analyzes the performance of a cooperative mixed terahertz (THz) and multi-antenna radio frequency (RF) system employing decode-and-forward relaying under imperfect channel state information. We consider line of sight in RF link and employ maximal ratio combining at the multi-antenna destination. The THz and RF links follow $\alpha $ - $\mu $ and $\kappa $ - $\mu $ distributions, respectively. We derive new closed-form expressions for the outage probability and average bit error rate of generalized Gray-coded rectangular quadrature amplitude modulation. We also evaluate asymptotic expressions to assess diversity order. We examine the impact of THz and RF link fading parameters, number of antennas at the destination, and estimation error. Finally, all theoretical findings are validated through simulations.