Joint Radar-Communication System Design Based on FDA-MIMO Via Frequency Index Modulation

The index modulation based on multiple-antenna architecture is a prospective information embedding approach for the joint radar-communication system (JRCS). Current investigations mainly focus on applying the spatial and frequency index modulation in phased array (PA) radar and multiple-input multiple-output (MIMO) radar. In this article, we devise an information embedding strategy by combining phase modulation and frequency index modulation for random frequency diverse array (RFDA) based on MIMO radar, which can perform joint range and angle estimation, which can not be accomplished in the dual-function systems based on PA and MIMO radar. Considering the time-variance of the transmit waveform, we propose a multichannel receiver for the JRCS. For radar subsystem, the impact of the random frequency assignment on the transmit-receive virtual beampattern and Cramér-Rao bounds (CRBs) of range and angle are analyzed. For communication, a ML detector with maximum ratio combining (MRC) assistance is adopted to improve the accuracy of the information decoding. Extensive numerical results are presented to verify the feasibility and effectiveness of the proposed system scheme.