Weighted Sum Rate Optimization for Movable Antenna Enabled Near-Field ISAC

2025-10-22

AI Summary

This paper addresses joint design in near-field integrated sensing and communication (ISAC) systems, aiming to maximize the weighted sum rate (WSR) of communication users under a minimum sensing signal-to-interference-plus-noise ratio (SINR) constraint. Specifically, it jointly optimizes movable antenna (MA) positions, sensing transmit beamforming, sensing receive combining, and communication precoding. It is the first work to incorporate MAs into the near-field ISAC framework and proposes an alternating optimization algorithm grounded in the spherical-wave propagation model. Simulation results demonstrate that the proposed scheme significantly improves WSR over conventional fixed-antenna systems; sensing performance is highly sensitive to the minimum SINR threshold, and system performance is maximized when higher weights are assigned to users closer to the base station. The core contribution lies in establishing a unified near-field MA-ISAC co-design paradigm, enabling synergistic gains between sensing and communication functionalities.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Multiagent Systems: Agent Communication
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Novel mobile and WoT systems, and system-of-systems
• Search and Retrieval-Augmented AI: Personalized, context-aware and across-device search
• Security and Privacy: Large-scale security measurements

Abstract

Integrated sensing and communication (ISAC) has been recognized as one of the key technologies capable of simultaneously improving communication and sensing services in future wireless networks. Moreover, the introduction of recently developed movable antennas (MAs) has the potential to further increase the performance gains of ISAC systems. Achieving these gains can pose a significant challenge for MA-enabled ISAC systems operating in the near-field due to the corresponding spherical wave propagation. Motivated by this, in this paper we maximize the weighted sum rate (WSR) for communication users while maintaining a minimal sensing requirement in an MA-enabled near-field ISAC system. To achieve this goal, we propose an algorithm that optimizes the sensing receive combiner, the communication precoding matrices, the sensing transmit beamformer and the positions of the users'MAs in an alternating manner. Simulation results show that using MAs in near-field ISAC systems provides a substantial performance advantage compared to near-field ISAC systems with only fixed antennas. Additionally, we demonstrate that the highest WSR is obtained when larger weights are allocated to the users placed closer to the BS, and that the sensing performance is significantly more affected by the minimum sensing signal-to-interference-plus-noise ratio (SINR) threshold compared to the communication performance.

Problem

• Optimizing weighted sum rate for communication users
• Maintaining minimal sensing requirements in near-field ISAC
• Enhancing performance through movable antenna positioning optimization

Innovation

• Optimizes movable antenna positions for performance gains
• Alternates optimization of beamforming and combining matrices
• Enhances near-field integrated sensing and communication systems