Random ISAC Signals Deserve Dedicated Precoding

Shihang Lu1; Fan Liu1; Fuwang Dong1; Yifeng Xiong2; Jie Xu3; Ya-Feng Liu4; Shi Jin5

2024

10.1109/TSP.2024.3427373

IEEE Transactions on Signal Processing   影响因子和分区

1941-0476

Radar systems typically employ well-designed deterministic signals for target sensing, while integrated sensing and communications (ISAC) systems have to adopt random signals to convey useful information. This paper analyzes the sensing and ISAC performance relying on random signaling in a multiantenna 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 random ISAC signals. Then, we investigate a data-dependent precoding (DDP) scheme to minimize the ELMMSE in sensing-only scenarios, which attains the optimized performance at the cost of high implementation overhead. To reduce the cost, we present an alternative data-independent precoding (DIP) scheme by stochastic gradient projection (SGP). Moreover, 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, 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 the signal sample covariance matrix as deterministic, which proves that random ISAC signals deserve dedicated precoding designs.

SCI ; EI

第一

ENGINEERING

1.School of System Design and Intelligent Manufacturing (SDIM), Southern University of Science and Technology, Shenzhen, China
2.School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing, China
3.School of Science and Engineering (SSE) and the Future Network of Intelligence Institute (FNii), The Chinese University of Hong Kong (Shenzhen), Shenzhen, China
4.State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China
5.National Mobile Communications Research Laboratory, Southeast University, Nanjing, China

Shihang Lu,Fan Liu,Fuwang Dong,et al. Random ISAC Signals Deserve Dedicated Precoding[J]. IEEE Transactions on Signal Processing,2024,PP(99).

Shihang Lu.,Fan Liu.,Fuwang Dong.,Yifeng Xiong.,Jie Xu.,...&Shi Jin.(2024).Random ISAC Signals Deserve Dedicated Precoding.IEEE Transactions on Signal Processing,PP(99).

Shihang Lu,et al."Random ISAC Signals Deserve Dedicated Precoding".IEEE Transactions on Signal Processing PP.99(2024).