Transmit and Reflect Beamforming for Max-Min SINR in IRS-Aided MIMO Vehicular Networks

6G vehicular networks will require massive connectivity among vehicles and Road Side Units (RSUs) to enable number of safety and non-safety applications. Intelligent Reflecting Surface (IRS) will be a vital part of 6G vehicular networks, providing features such as enhanced line of sight communication, extended coverage range and high data rate transmission. In this paper, we consider a multiple IRSs assisted multi-vehicle Multiple-Input Multiple-Output (MIMO) communication system and optimize the transmit beamforming vectors at the transmitter and reflect beamforming (phase shifts) at each IRS to achieve max-min Quality of Service (QoS) in the form of weighted Signal-to-Interference-Plus-Noise Ratio (SINR). In particular, we divide the optimization problem into two Semidefinite Relaxation (SDR) sub-problems and solve them iteratively using the alternate optimization technique. Simulation results show that the proposed technique significantly increases the sum-rate and SINR of the vehicular network.