Joint Localization and Predictive Beamforming in Vehicular Networks: Power Allocation Beyond Water-Filling

This paper explores tailored power allocation (PA) for dual functional radar-communication (DFRC) in the vehicle-to-infrastructure (V2I) network, where a road side unit (RSU) provides both localization and communication services to multiple vehicles. Going beyond classical communications-optimal water-filling solutions, we formulate a PA optimization problem, which minimizes the summation of the Cramér-Rao bound (CRB) for multiple vehicles, subject to downlink sum-rate constraint. We prove that the problem can be solved in closed-form for given sum-rate requirement regions. Numerical results demonstrate that our approach achieves significantly lower estimation errors while improving the communication rate, as compared to the classical water-filling.