Sensing-Efficient Transmit Beamforming for ISAC with MIMO Radar and MU-MIMO Communication

• Published in: Remote sensing (Basel, Switzerland) Switzerland), 2024-08, Vol.16 (16), p.3028
• Main Authors: Liu, Huimin, Li, Yong, Cheng, Wei, Dong, Limeng, Yan, Beiming
• Format: Article
• Language: English
• Subjects: antennae; Approximation; Beamforming; Business metrics; Communication; Communications systems; communications technology; Design; Design optimization; Design parameters; Downlinking; Effectiveness; integrated sensing and communication (ISAC); joint transmit beamforming; MIMO communication; MIMO radar; MU-MIMO; Noise threshold; Optimization; Performance evaluation; Power; Radar; Radar beams; Regularization; remote sensing; Splitting; system optimization; Target detection; Tradeoffs; Transmitters; Waveforms
• ISSN: 2072-4292; 2072-4292
• DOI: 10.3390/rs16163028

We focus on an integrated sensing and communication (ISAC) system—a single platform equipped with multiple antennas transmitting a waveform to detect targets and communicate with downlink users. Due to spectrum sharing between multiple-input–multiple-output (MIMO) radar and multiuser MIMO (MU-MIMO) communication, beamforming is becoming increasingly important as a technique that enables the creation of directional beams. In this paper, we propose a novel joint transmit beamforming design scheme that employs a beam pattern approximation strategy for radar sensing and utilizes rate-splitting for multiuser communication offering advanced interference management strategies. The optimization problems are formulated from both radar-centric and trade-off viewpoints. First, we propose a radar-centric beamforming scheme to achieve sensing efficiency through beam pattern approximation, while requiring the fairness signal-to-interference-plus-noise ratio (SINR) to be higher than a given threshold to guarantee a minimal level of communication quality, while the obtained performance for the communication system is limited in this scheme. To address this problem, we propose a beamforming design scheme from a trade-off viewpoint that flexibly optimizes both sensing and communication performances with a regularization parameter. Finally, we propose a partial rate-splitting-based beamforming design method aimed at maximizing the effective sensing power, with the constraint of a minimal sum rate for downlink users. Numerical results are provided to assess the effectiveness of all proposed schemes.