Single Versus Double IRS-Assisted Networks: A Comparative Analysis Using Practical Phase Shifting

Intelligent reflecting surfaces (IRSs) have been considered to revolutionize beyond 5G and 6G systems as they help increase signal strength through their ability to control radio environments effectively. Introducing IRS assistance in a single-input single-output (SISO) network has been proven to improve the system's performance. This paper compares the performance of a single IRS-assisted SISO system against a double IRS-assisted system under various wireless network setups. Our work relies on a shared allocation scheme of IRS elements, where a practical phase-dependent amplitude phase shift model is utilized along with discrete phase shifts to develop a reliable and energy-efficient system. We observe energy efficiency while altering system parameters to identify the limits where each system works better. The simulation results show that two IRSs perform better at large deployments, whereas a single IRS performs better in compact environments.