IRS-Aided Wireless Communication: From Physics to Channel Modeling and Characterization

Abstract

Intelligent reflecting surface has recently emerged as a cost-effective solution to overcome the deep fading and uncontrollable wireless environment. This leads to a need for studies on the wireless channels of IRS-aided wireless communication (IRSaWC). This paper proposes a novel channel modelling method for the IRSaWC by exploiting the physics characteristic of the electromagnetic (EM) field on the IRS and the modified Saleh-Valenzuela (SV) model. Firstly, the reflection on a single reflecting tile (RT) of the IRS is investigated in the presence of a misalignment between the RT’s configured incident angle and the actual incident angle, and the RT’s phase distortion. Then, the path loss and phase shift models for the reflected field are developed. Extending our study to the multiple-RT scenario and utilizing the modified SV model, the channel characteristic for the IRSaWC is determined. Our analysis shows that the information signal at the receiver experiences a Rice fading with controllable parameters. Theoretical results for the path loss, the channel’s parameters, and the received distortion power are derived; moreover, an approximate distribution for the combined signal-to-noise ratio (SNR) for IRS-aided multiple-antenna wireless systems (IRSaMAWSs) has been investigated with the aim of conducting further studies on theoretical performance for IRSaMAWSs

Keywords

• Intelligent reflecting surface
• channel modeling
• Rice distribution
• multiple-antenna system
• performance analysis