Near-Field IRS Configuration Techniques for Wideband Signals and THz Communications.

Motivated by the challenges of future 6G communications where near-field THz communications, intelligent reflective surfaces (IRSs) and ultra-wideband signals coexist, we investigate techniques for properly configuring the IRSs so as to maximize the communication data rate and reduce the losses due to the beam-squint effect. Our proposed techniques take into account the channel model, the power spectral density of the transmitted signal and the system geometry. Through simulations we evaluate the proposed solutions and compare against an upper bound we derived. Our results suggest rules for designing near-field IRS-aided communications and highlight the impact that the system geometry has on the performance.