Transceiver Design for Spectrum Sharing Between FD Cellular System and MIMO Radar

We consider the spectral coexistence between collocated multiple-input-multiple-output (MIMO) radar and a full-duplex (FD) MIMO cellular system. Considering imperfect channel state information and hardware impairments at the cellular base station (BS), we focus on the design of beamforming matrices at the cellular system via the minimization of sum mean-squared-errors such that the detection probability of the radar is not affected due to spectrum sharing. The formulated problem is non-convex and hence we convert it into an equivalent semidefinite programming problem and propose an iterative algorithm to find the optimal beamforming matrices. Numerical results verify the eminence of spectrum sharing, albeit certain tradeoffs. In particular, using the spectrum shared by the radar, the FD cellular system can achieve an area throughput of around 4-5 Mbps/m2for a reasonable self-interference cancellation of around-70 dB. However, to facilitate this, while also maintaining a detection probability of around 0.9, the MIMO radar needs to spend an extra power of around 3-4 dB.