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.

翻译：集成感知与通信（ISAC）已被认为是未来无线网络中能够同时提升通信与感知服务的关键技术之一。此外，近期发展的可移动天线（MAs）的引入有望进一步提高ISAC系统的性能增益。然而，在近场环境下，由于球面波传播特性，实现这些增益对基于可移动天线的ISAC系统构成显著挑战。基于此，本文在可移动天线赋能的近场ISAC系统中，以维持最低感知需求为前提，最大化通信用户的加权和速率（WSR）。为实现该目标，我们提出一种算法，交替优化感知接收组合器、通信预编码矩阵、感知发射波束成形器以及用户可移动天线的位置。仿真结果表明，与仅配备固定天线的近场ISAC系统相比，在近场ISAC系统中使用可移动天线可带来显著的性能优势。此外，我们证明当为靠近基站的用户分配较大权重时，可获得最高的加权和速率，且与通信性能相比，感知性能受最小感知信号与干扰加噪声比（SINR）阈值的影响更为显著。