Interference-Aware Integrated Uplink Communication and Downlink Sensing

Interferences between uplink communication and downlink radar sensing can severely impair the performance of the time-division duplex (TDD) multiple-input-multiple-output (MIMO) integrated sensing and communication (ISAC) system. In this paper, we propose an efficient joint downlink and uplink design to address this issue. Specifically, we jointly optimize the downlink radar sensing waveform and the uplink power allocation to minimize the weighted sum of sensing and communication mean squared errors (MSEs). Despite the non-convexity of the joint downlink and uplink design problem, we develop a majorization-minimization (MM) based algorithm to determine an efficient solution. The proposed algorithm is proved to be convergent. Moreover, as validated via simulation results, the proposed joint design can effectively mitigate the interference between uplink communication and radar sensing and provide remarkable performance gains over conventional separate design.