A Wideband MIMO Channel Model for Aerial Intelligent Reflecting Surface-Assisted Wireless Communications

TL;DR

This paper introduces a 3D wideband channel model for aerial IRS-assisted MIMO systems, capturing mobility and rotation effects, and proposes phase shift schemes that enhance channel capacity and statistical characteristics.

Contribution

It presents the first comprehensive 3D wideband channel model for aerial IRS-assisted MIMO systems considering mobility and rotation, along with effective phase shift strategies.

Findings

The model accurately captures channel characteristics.

Proposed phase shifts improve system capacity.

Paths involving IRS and LoS show similar traits in some scenarios.

Abstract

Compared to traditional intelligent reflecting surfaces(IRS), aerial IRS (AIRS) has unique advantages, such as more flexible deployment and wider service coverage. However, modeling AIRS in the channel presents new challenges due to their mobility. In this paper, a three-dimensional (3D) wideband channel model for AIRS and IRS joint-assisted multiple-input multiple-output (MIMO) communication system is proposed, where considering the rotational degrees of freedom in three directions and the motion angles of AIRS in space. Based on the proposed model, the channel impulse response (CIR), correlation function, and channel capacity are derived, and several feasible joint phase shifts schemes for AIRS and IRS units are proposed. Simulation results show that the proposed model can capture the channel characteristics accurately, and the proposed phase shifts methods can effectively improve the channel statistical characteristics and increase the system capacity. Additionally, we observe that in certain scenarios, the paths involving the IRS and the line-of-sight (LoS) paths exhibit similar characteristics. These findings provide valuable insights for the future development of intelligent communication systems.