Beamforming Design for Multi-User MIMO-OFDM Integrated Sensing and Communication Systems

To resolve the spectrum scarcity and realize the perceptive network, integrated sensing and communication (ISAC) systems have been widely studied. However, the study of the multi-user ISAC system based on the multiple-input multiple-output (MIMO)-orthogonal frequency division multiplexing (OFDM) architecture is far from complete. Thus, this paper aims to fill this gap by investigating the beamforming design for multi-user MIMO-OFDM ISAC systems. By studying the beamforming effect on the range-Doppler domain of the radar sensing and the system capacity, a design problem is formulated. Then, by converting the capacity maximization to the weighted minimum mean square error minimization along with the use of successive convex approximation, an iterative approach is proposed to solve the design problem. Simulation results show that our design approach can outperform the reference methods in the literature.