Intelligent Reflecting Surface-Assisted mmWave Communication With Lens Antenna Array

In millimeter wave (mmWave) communication, lens antenna array has been considered as a potential technique to combat the severe path loss. However, blockage effect still exists. To address this issue, we design an intelligent reflecting surface (IRS) assisted wideband mmWave communication system with limited radio frequency (RF) chains. This is first attempt integration of IRS and array. The designed can realize high robust, low-complexity cost-effective communication. achieve desired performance, derive signal-to-interference-plus-noise ratio (SINR) expression intersymbol interference, then formulate SINR maximization problem, by jointly considering beamforming vector at base station RF chains reflection coefficient matrices discrete phase levels. problem intractable non-convex. solve it, optimize quadratic transformation closed-form expression, handled sparse optimization, where $l_{0}$ norm approximated notation="LaTeX">$l_{1}$ norm. Finally, simulation results demonstrate advantages our proposed algorithm compared benchmark schemes, e.g., 5 dB gain be achieved existing algorithm.