Low Complexity Joint Radar-Communication Systems Design in the RF Domain

In this paper, we propose an efficient and low hardware complexity multiuser multiple-input multiple-output (MU-MIMO) joint radar-communication (JRC) system. The proposed system is implemented via an analog phase shifting network and a variable gain amplifier. The proposed system simultaneously supports the downlink communication with multiple users and radar target detection through its multiple antenna transmitter. We consider two design architectures for the phase shifting network: infinite and finite resolution phase-shifters. Furthermore, the energy consumption of the both the proposed architectures is modeled. For these two cases, the transmit waveform is designed in the radiofrequency (RF) domain such that the downlink multi-user interference is minimized while the desired radar beampattern is achieved under architecture specific constraints. To do so, a difficult nonconvex optimization problem is formulated and solved by a novel algorithmic solution based on the primal-dual framework. The numerical results verify the good performance and significant gains in the energy efficiency of the proposed approach with respect to the existing state-of-the-art fully-digital methods.