Cramér-Rao Bound Optimization for Joint Radar-Communication Beamforming

In this paper, we propose multi-input multi-output (MIMO) beamforming designs towards joint radar sensing and multi-user communications. We employ the Cram\'er-Rao bound (CRB) as a performance metric of target estimation, under both point extended scenarios. then minimizing CRB while guaranteeing pre-defined level signal-to-interference-plus-noise ratio (SINR) for each communication user. For single-user scenario, derive closed form optimal solution cases targets. show that problems can be relaxed into semidefinite programming by using relaxation approach, prove global optimum always obtained. Finally, demonstrate numerically globally solutions are reachable via proposed methods, which provide significant gains in estimation over state-of-the-art benchmarks.