Transmit/Receive Beamforming for MIMO-OFDM based Dual-Function Radar and Communication

For a Multiple-Input Multiple-Output (MIMO)-Orthogonal Frequency-Division Multiplexing (OFDM) based dual-function radar and communication (DFRC), the problem of transmit/receive beamforming with the constraints of Quality of Server (QoS) and transmit power is studied in this paper. The degrees of freedom for system design are the transmit/receive beampatterns at the radar array, and the receive beampattern at the communication array. Firstly, we adopt Kullback-Leibler divergence (KLD) as design metrics and formulate the design problem as a KLD maximization problem with QoS and transmit power constraints. Secondly, we solve the original non-convex problem through the proposed alternating direction sequential relaxation programming (ADSRP) algorithm, which iteratively optimizes three subproblems: 1) dual-function transmit beamforming with the constraints of QoS and transmit power; 2) radar receive beamforming; and 3) communication receive beamforming. We analytical provide the monotonic improvement and bound of KLD, which guarantees the convergence of the ADSRP algorithm. Finally, simulation results are provided to evaluate the effects of different QoS requirements and peak-to-average-power ratio (PAPR) constraints in terms of power allocation scheme and radar detection performance, compared to the traditional radar system (TRS).