Title：Random ISAC Signals Deserve Dedicated Precoding
Time/Venue: 11月4日（周六）下午15：30，無線谷 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.
報告人簡介：劉凡，南方科技大學助理教授（副研究員），博士生導師。中國科協青年托舉人才，廣東省“珠江計劃”引進青年拔尖人才，瑪麗·居裡學者，IEEE高級會員，中國通信學會高級會員。主要研究方向為通信感知一體化、車聯網與智能交通。發表論文100餘篇，獲引5000餘次，其中入選ESI高被引論文7篇。曾獲得2023年IEEE通信學會萊斯獎 (Stephan O. Rice Prize)，2023年IEEE ICC最佳論文獎，2023年IEEE/CIC ICCC最佳論文獎，2022年中國通信學會科技進步一等獎，2021年IEEE信号處理學會青年作者最佳論文獎，2019年中國電子學會優秀博士學位論文獎。出版專著入選國家“十四五”重點出版物專項規劃項目、工信學術出版基金。2021-2023連續三年入選斯坦福大學全球2%頂尖科學家榜單。擔任IEEE通信學會通感一體化新興技術委員會學術主席，IEEE COMML和IEEE OJSP編委，以及IEEE JSAC、IEEE WCM、IEEE VTM、《中國通信》客座編委。同時，兼任華為技術有限公司獨立顧問，《中興通訊技術》産學研青年委員會委員，以及IMT-2030 (6G) 通感一體化任務組專家。
