Joint Power Allocation for Multicarrier Radar and Communication Coexistence

This paper examines the coexistence of radar and communication systems on a common frequency band using multicarrier waveforms. We consider a radar-centric sharing scenario where the radar needs to meet a minimum performance constraint, measured by the signal-to-interference-plus-noise ratio (SINR). A heuristic solution can be developed using a greedy search (GS) method, which lets the radar transmit peak power on its best subcarrier to meet the SINR constraint, and then assigns the rest subcarriers to the communication system to maximize its throughput. The GS method is a subcarrier-allocation based solution. We propose herein a sharing based approach, which allows the radar and communication systems to occupy the same subcarrier, but controls the mutual interference through joint power allocation. This leads to a non-convex problem that maximizes the communication throughput under a radar SINR constraint, as well as total and per-subcarrier power constraints for both the radar and communication systems. The problem is solved by an alternating optimization and sequential convex programming algorithm. Simulation results show the proposed sharing based approach significantly outperforms the GS method in various interference scenarios.