Adaptive Waveform Optimization for MIMO Integrated Sensing and Communication Systems Based on Mutual Information

In this paper, we propose an adaptive waveform design and optimization scheme for integrated sensing and communication (ISAC) systems. We modify the transmitted waveform to improve the degraded sensing performance caused by the randomness of the original communication waveform. Specifically, we utilize the spacial, time, and frequency resources unoccupied by the communication to transmit sensing paddings. Based on the modified transmitted waveform, we derive its sensing mutual information (MI), which is applied as a performance metric to optimize the waveform. By maximizing the sensing MI, we obtain the closed-form solution of the optimal waveform and its precoding matrix. Finally, we verify numerically that the proposed scheme brings significant improvement to sensing performance.