FDA-MIMO transmit beamforming design for dual-function radar-communication systems based on beampattern modulation

Integrating frequency diversity array (FDA) with multiple-input multiple-output (MIMO) technology enables the dual-function radar-communication (DFRC) system to independently control the beam power in both range and angle domains. This paper proposes an FDA-MIMO transmit beamforming design for DFRC systems based on beampattern modulation. Initially, to achieve beampattern modulation, a signal model is developed by employing transmit beamforming on orthogonal waveforms. Following this, a two-dimensional range-angle transmit-receive beampattern is derived through receiving matching filtering. Fulfilling the communication function involves adjusting the transmit-receive beampattern's phase at the user's location, a constraint that also imposes to the beamforming optimization model. The objective function is to minimize the mean squared error (MSE) between the designed and expected beamforming matrices, aiming to enhance radar efficiency. The established convex optimization model is solved by employing the interior point algorithm. The simulation results verify the effectiveness of the designed beamforming algorithm.