Group Movable Antenna With Flexible Sparsity: Joint Array Position and Sparsity Optimization

TL;DR

This paper introduces a group movable antenna architecture that allows collective movement and flexible sparsity optimization, significantly enhancing multi-user communication performance by jointly optimizing array position and sparsity.

Contribution

It proposes a novel group movable antenna system with joint position and sparsity optimization, reducing complexity and improving performance over fixed-position antennas.

Findings

Joint optimization yields significant sum rate improvements.

Group movement simplifies antenna control and deployment.

Flexible sparsity adapts to different channel conditions.

Abstract

Movable antenna (MA) is a promising technology to exploit the spatial variation of wireless channel for performance enhancement, by dynamically varying the antenna position within a certain region. However, for multi-antenna communication systems, moving each antenna independently not only requires prohibitive complexity to find the optimal antenna positions, but also incurs sophisticated movement control in practice. To address this issue, this letter proposes a new MA architecture termed group MA (GMA), enabling the group movement of all elements collectively in a continuous manner, and simultaneously achieving flexible array architecture by antenna selection (AS). In this letter, we focus on the uniform sparse array based GMA, where equally spaced antenna elements are selected to achieve desired array sparsity. The array position and sparsity level are jointly optimized to maximize the sum rate of the multi-user communication system. Numerical results verify the necessity to optimize the position and sparsity of GMA, and considerable performance gain is achieved as compared to the conventional fixed-position antenna (FPA).