Joint Transmit and Reflecting Beamforming Design in IRS-Assisted mmWave MU-MISO Systems with ZF-Assisted SA Algorithm

We investigate the use of intelligent reflecting surfaces (IRSs) to mitigate blockage caused by signal attenuation in millimeter-wave massive multiuser multiple-input single-output wireless systems. This involves jointly designing transmit beamforming at the base station and reflecting beamforming at the IRS. Our proposed solution combines zero-forcing (ZF)-based transmit beamforming with a simulated annealing (SA) algorithm for reflecting beamforming design. We assess the performance of our algorithm by comparing it with two existing approaches, and the results demonstrate that optimizing IRS phase shifts significantly enhances spectral efficiency. Our ZF-assisted SA algorithm outperforms other methods, confirming its effectiveness.