Joint design of hybrid transmitter and receiver in multi-user OFDM dual-function radar-communication system

This paper investigates the design of hybrid beamforming transmitter, radar receiver, and communication receiver in an orthogonal frequency division multiplexing (OFDM) dual-function radar-communication (DFRC) system. Specifically, we formulate the joint design problem as optimizing the spectrum efficiency (SE) of communication and the signal-to-interference noise ratio (SINR) of radar sensing. Due to the coupling between the digital and analog beamformers in the hybrid beamforming structure, the resultant problem is NP-hard. Towards this end, a consensus alternating direction method of multipliers (CADMM) approach is developed, by decoupling the digital precoder and the analog precoder with auxiliary variables. In each iteration, the digital precoder can be analytically obtained, while the analog precoder is designed via a phase-only beamforming method. Both the communication and radar receivers are optimized through the generalized eigenvalue decomposition. Numerical simulations are provided to demonstrate the effectiveness of the proposed design approach.