Modeling and Analysis of MIMO Multipath Channels With Aerial Intelligent Reflecting Surface

Recently, intelligent reflecting surface (IRS) has become a research focus for its capability of controlling the radio propagation environments. Compared to conventional terrestrial IRS, aerial IRS (AIRS) exploiting unmanned vehicle (UAV)/high-altitude platform (HAP) can provide better deployment flexibility. To this end, three-dimensional (3D) one-cylinder model is first developed AIRS-assisted multiple-input multiple-output (MIMO) narrowband channels. In order change wireless channel with AIRS and create favorable environment, we propose novel method designing phase-shifts elements. Based on model, impulse response (CIR), space-time correlation function, capacity are derived thoroughly investigated. A key observation in paper that multipath Doppler effects environments be effectively mitigated via adjusting IRS. More specifically, special absence any scatterers, it found fading completely eliminated by IRSs. While general multiple small number elements also significantly reduce spread deep fades numerical investigation correlations, shown non-stationarity not introduced into time domain when phase shift linear related time. Moreover, improved proposed methods. Finally, non-ideal IRSs considered using results poor performances compared ideal These conclusions will fundamental support developing controllable future sixth-generation (6G) networks.