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Title: SNR/CRB-Constrained Joint Beamforming and Reflection Designs for RIS-ISAC Systems
In this paper, we investigate the integration of integrated sensing and communication (ISAC) and reconfigurable intelligent surfaces (RIS) for providing wide-coverage and ultrareliable communication and high-accuracy sensing functions. In particular, we consider an RIS-assisted ISAC system in which a multi-antenna base station (BS) simultaneously performs multiuser multi-input single-output (MU-MISO) communications and radar sensing with the assistance of an RIS. We focus on both target detection and parameter estimation performance in terms of the signal-to-noise ratio (SNR) and Cramér-Rao bound (CRB), respectively. Two optimization problems are formulated for maximizing the achievable sum-rate of the multi-user communications under an SNR constraint for target detection or a CRB constraint for parameter estimation, the transmit power budget, and the unit-modulus constraint of the RIS reflection coefficients. Efficient algorithms are developed to solve these two complicated non-convex problems. We then extend the proposed joint design algorithms to the scenario with imperfect self-interference cancellation. Extensive simulation results demonstrate the advantages of the proposed joint beamforming and reflection designs compared with other schemes. In addition, it is shown that more RIS reflection elements bring larger performance gains for directof- arrival (DoA) estimation than for target detection.  more » « less
Award ID(s):
2322191 2225575
PAR ID:
10643386
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
IEEE
Date Published:
Journal Name:
IEEE Transactions on Wireless Communications
Volume:
23
Issue:
7
ISSN:
1536-1276
Page Range / eLocation ID:
7456 to 7470
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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