Blockage-aware Hierarchical Codebook Design for RIS-Assisted Movable Antenna Systems

TL;DR

This paper introduces a blockage-aware hierarchical codebook design for RIS-assisted movable antenna systems, enhancing energy efficiency and reducing beam training overhead at mm-Wave frequencies.

Contribution

It proposes a novel blockage-aware codebook design integrating blockage detection with the Gerchberg-Saxton algorithm and a two-stage approach for joint beamforming and RIS optimization.

Findings

Improved energy efficiency in RIS-assisted MA systems.

Reduced beam training overhead.

Enhanced practical deployment potential.

Abstract

In this paper, we propose a novel blockage-aware hierarchical beamforming framework for movable antenna (MA) systems operating at millimeter-wave (mm-Wave) frequencies. While existing works on MA systems have demonstrated performance gains over conventional systems, they often neglect the design of specialized codebooks to leverage MA's unique capabilities and address the challenges of increased energy consumption and latency inherent to MA systems. To address these aspects, we first integrate blockage detection into the codebook design process based on the Gerchberg-Saxton (GS) algorithm, significantly reducing inefficiencies due to beam evaluations done in blocked directions. Then, we use a two-stage approach to reduce the complexity of the joint beamforming and Reconfigurable Intelligent Surfaces (RIS) optimization problem. The simulations demonstrate that the proposed adaptive codebook successfully improves the Energy Efficiency (EE) and reduces the beam training overhead, substantially boosting the practical deployment potential of RIS-assisted MA systems in future wireless networks.