Transmit antenna selection for millimeter-wave communications using multi-RIS with imperfect transceiver hardware

This article presents a comprehensive exploration of the synergy between transmit antenna selection (TAS) and reconfigurable intelligent surfaces (RISs) in millimeter-wave (MW) communication systems, considering the impact of practical conditions. Notably, it accounts for imperfect transceiver hardware (ITH) at both the transmitter and receiver. Additionally, real-world channel models and receiver noise statistics are integrated into the analysis, providing a realistic representation of wireless systems in future networks. Mathematical formulas of outage probability (OP) and system throughput (ST) of the multi-RIS-assisted MW communications with ITH and TAS (shortened as the considered communications) are derived for analyzing the system behaviors. These formulas facilitate a comprehensive examination of system behavior. Through a series of comparative scenarios, including evaluations of OP and ST with and without TAS, with and without RISs, and with and without ITH (where the absence of ITH is denoted as perfect transceiver hardware, or PTH), the study substantiates the substantial advantages of TAS and RISs while shedding light on the significant influence of ITH. It is demonstrated that even in the presence of ITH, MW communication performance can be dramatically enhanced by optimizing the number of transmit antennas, selecting suitable carrier frequencies and RIS placements, and utilizing appropriate bandwidth. Ultimately, the derived formulas are rigorously validated through Monte-Carlo simulations, reinforcing the credibility of the findings.