Title：Random ISAC Signals Deserve Dedicated Precoding
Time/Venue: 11月4日（周六）下午15：30，无线谷 A1208
Abstract：Radar systems typically employ well-designed deterministic signals for target sensing. In contrast to that, integrated sensing and communications (ISAC) systems have to adopt random signals to convey useful information, potentially causing sensing performance degradation. In this talk, we will analyze the sensing and ISAC performance relying on random signaling over a multi-antenna system. Towards this end, we define a new sensing performance metric, namely, ergodic linear minimum mean square error (ELMMSE), which characterizes the estimation error averaged over the randomness of ISAC signals. Then, we investigate a data-dependent precoding (DDP) scheme to minimize the ELMMSE, which attains the optimized sensing performance at the price of high implementation overhead. To reduce the cost, we present an alternative data-independent precoding (DIP) scheme and propose a stochastic gradient projection (SGP) algorithm for ELMMSE minimization, which can be trained offline by locally generated signal samples. To reveal more insights into the precoding designs, we shed light on the optimal structures of both sensing-only DDP and DIP precoders. As a further step, we extend the proposed DDP and DIP approaches to ISAC scenarios by explicitly constraining the achievable communication rate for ELMMSE minimization problems, which are solved via a tailored penalty-based alternating optimization algorithm. Our numerical results demonstrate that the proposed DDP and DIP methods achieve substantial performance gains over conventional ISAC signaling schemes that treat signal sample covariance matrix as deterministic, which prove that random ISAC signals deserve dedicated precoding designs.
报告人简介：刘凡，南方科技大学助理教授（副研究员），博士生导师。中国科协青年托举人才，广东省“珠江计划”引进青年拔尖人才，玛丽·居里学者，IEEE高级会员，中国通信学会高级会员。主要研究方向为通信感知一体化、车联网与智能交通。发表论文100余篇，获引5000余次，其中入选ESI高被引论文7篇。曾获得2023年IEEE通信学会莱斯奖 (Stephan O. Rice Prize)，2023年IEEE ICC最佳论文奖，2023年IEEE/CIC ICCC最佳论文奖，2022年中国通信学会科技进步一等奖，2021年IEEE信号处理学会青年作者最佳论文奖，2019年中国电子学会优秀博士学位论文奖。出版专著入选国家“十四五”重点出版物专项规划项目、工信学术出版基金。2021-2023连续三年入选斯坦福大学全球2%顶尖科学家榜单。担任IEEE通信学会通感一体化新兴技术委员会学术主席，IEEE COMML和IEEE OJSP编委，以及IEEE JSAC、IEEE WCM、IEEE VTM、《中国通信》客座编委。同时，兼任华为技术有限公司独立顾问，《中兴通讯技术》产学研青年委员会委员，以及IMT-2030 (6G) 通感一体化任务组专家。
