Flexible Rate-Splitting Multiple Access for Near-Field Integrated Sensing and Communications

作     者：Zhou, Jiasi Zhou, Cong Zeng, Cheng Tellambura, Chintha 

作者机构：School of Medical Information and Engineering Xuzhou Medical University Xuzhou221004 China School of Electronic and Information Engineering Harbin Institute of Technology Harbin150001 China National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Department of Electrical and Computer Engineering University of Alberta EdmontonABT6G 2R3 Canada 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Convex optimization 

摘      要：This letter presents a flexible rate-splitting multiple access (RSMA) framework for near-field (NF) integrated sensing and communications (ISAC). The spatial beams configured to meet the communication rate requirements of NF users are simultaneously leveraged to sense an additional NF target. A key innovation lies in its flexibility to select a subset of users for decoding the common stream, enhancing interference management and system performance. The system is designed by minimizing the Cramér-Rao bound (CRB) for joint distance and angle estimation through optimized power allocation, common rate allocation, and user selection. This leads to a discrete, non-convex optimization problem. Remarkably, we demonstrate that the preconfigured beams are sufficient for target sensing, eliminating the need for additional probing signals. To solve the optimization problem, an iterative algorithm is proposed combining the quadratic transform and simulated annealing. Simulation results indicate that the proposed scheme significantly outperforms conventional RSMA and space division multiple access (SDMA), reducing distance and angle estimation errors by approximately 100% and 20%, respectively. Copyright © 2024, The Authors. All rights reserved.