Tri-hybrid beamforming boosts energy efficiency in large antenna arrays
Tri-Hybrid Beamforming Design for Large-Scale MIMO ISAC Systems
Information Theory
Summary
Large antenna arrays in communication systems use beamforming to send and receive signals efficiently. The authors studied a special beamforming setup that combines three types of hardware, including new low-cost antennas called dynamic metasurface antennas. Their goal was to improve both data transmission and sensing using the same system. They created a clever method to balance these goals while using less power and showed their approach works well with only small trade-offs in performance.
What this means in practice
- •For wireless network engineers: Design energy-efficient antenna arrays that improve data rates and sensing capabilities simultaneously using tri-hybrid beamforming hardware.
- •For defense radar system designers: Integrate communication and sensing functions in radar systems with enhanced energy efficiency by implementing tri-hybrid multiple antenna arrays.
Authors
Tianyu Fang, Mengyuan Ma, Markku Juntti, Inkyu Lee, Joonhyuk Kang, Nhan Thanh Nguyen
Abstract
Tri-hybrid multiple-input multiple-output (MIMO) architectures have been proposed as a promising solution for enabling energy-efficient communications systems in large-scale antenna arrays by replacing conventional antenna arrays in hybrid beamforming (HBF) systems with low-cost dynamic metasurface antennas (DMAs). In this work, we investigate beamforming design for integrated sensing and communications (ISAC) systems based on tri-HBF architectures, with the objective of jointly enhancing the communications sum rate and sensing sum mutual information. Specifically, we formulate a weighted multi-objective optimization problem that balances communications throughput and sensing mutual information, subject to a total transmit power consumption constraint and the physical limitations inherent to tri-HBF architectures. By exploiting the problem structure, we develop an efficient iterative algorithm with closed-form updates to solve the non-convex optimization problem with low complexity. Numerical results are provided to evaluate the performance of the proposed tri-HBF architecture in various setups. The results demonstrate that the proposed tri-HBF architecture can achieve significant improvement in energy efficiency (EE) compared to the conventional hybrid MIMO and DMA-only configurations, at the cost of minor degradations in sum rate and sensing mutual information.