학술논문
Beamforming Design in Intelligent Reflecting Surface Aided Multicast System in Ultra-High Frequency Bands With Large-Scale Antenna Array
Document Type
Periodical
Source
IEEE Wireless Communications Letters IEEE Wireless Commun. Lett. Wireless Communications Letters, IEEE. 13(5):1429-1433 May, 2024
Subject
Language
ISSN
2162-2337
2162-2345
2162-2345
Abstract
As the next generation mobile communication system goes to ultra-high frequency bands, such as terahertz (THz), we may achieve angular orthogonality by implementing a large-scale antenna-array. We maximize the achievable multicast rate among all users by jointly designing the hybrid transmit beamformers and the analog reflecting beamformer, subject to the power budget and norm on the phase-shifters. A novel asymptotically optimal structure of the reflecting beamformer at the IRS is found, based on which a closed-form asymptotically optimal solution of the hybrid transmit beamformer and the reflecting beamformer is also obtained. Numerical results demonstrates the feasibility of exploiting the angular orthogonality in the beamforming design of an IRS aided THz communication system.