Energy Efficiency Optimization in IRS-Enhanced mmWave Systems with Lens Antenna Array

TL;DR

This paper proposes an IRS-enhanced mmWave system with lens antennas and develops an optimization algorithm to maximize energy efficiency, demonstrating significant improvements through simulations.

Contribution

It introduces a novel joint beamforming optimization approach for IRS-enhanced mmWave systems with lens antennas, addressing energy efficiency.

Findings

Significant energy efficiency gains achieved in simulations.

Effective joint optimization of transmit and reflect beamforming.

Algorithm converges efficiently under various scenarios.

Abstract

In millimeter wave (mmWave) systems, the advanced lens antenna array can effectively reduce the radio frequency chains cost. However, the mmWave signal is still vulnerable to blocking obstacles and suffers from severe path loss. To address this problem, we propose an intelligent reflect surface (IRS) enhanced multi-user mmWave communication system with lens antenna array. Moreover, we attempt to optimize energy efficiency in the proposed system. An energy efficiency maximization problem is formulated where the transmit beamforming at base station and the reflect beamforming at IRSs are jointly considered. To solve this non-convex problem, we propose an algorithm based on the alternating optimization technique. In the proposed algorithm, the transmit beamforming is handled by the sequential convex approximation method and the reflect beamforming is optimized based on the quadratic transform method. Our simulation results show that the proposed algorithm can achieve significant energy efficiency improvement under various scenarios.