Hybrid Beamforming for Millimeter Wave MIMO Integrated Sensing and Communications

• Published in: IEEE communications letters Vol. 26; no. 5; pp. 1136 - 1140
• Main Authors: Qi, Chenhao, Ci, Wei, Zhang, Jinming, You, Xiaohu
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Array signal processing; Beamforming; Communication; Constraints; Dual-functional radar-communication (DFRC); hybrid beamforming; integrated sensing and communications (ISAC); Interference; joint communications and radar (JCR); millimeter wave (mmWave) communications; Millimeter waves; MIMO communication; Optimization; Phase shifters; Phasors; Radar antennas; Radar arrays; Radar beams; Radio frequency; Sensors; Signal to noise ratio
• ISSN: 1089-7798; 1558-2558
• DOI: 10.1109/LCOMM.2022.3157751

In this letter, we consider hybrid beamforming for millimeter wave (mmWave) MIMO integrated sensing and communications (ISAC). We design the transmit beam of a dual-functional radar-communication (DFRC) base station (BS), aiming at approaching the objective radar beam pattern, subject to the constraints of the signal to interference-plus-noise ratio (SINR) of communication users and total transmission power of the DFRC BS. To provide additional degree of freedom for the beam design problem, we introduce a phase vector to the objective beam pattern and propose an alternating minimization method to iteratively optimize the transmit beam and the phase vector, which involves second-order cone programming and constrained least squared estimation, respectively. Then based on the designed transmit beam, we determine the analog beamformer and digital beamformer subject to the constant envelop constraint of phase shifter network in mmWave MIMO, still using the alternating minimization method. Simulation results show that under the same SINR constraint of communication users, larger antenna array can achieve better radar beam quality.