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

Abstract

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 the spatial and frequency index modulation applied in phased array (PA) radar and multiple-input multiple-output (MIMO) radar. In this article, we design an information embedding strategy by combining phase modulation and frequency index modulation for random frequency diverse array (RFDA) based on MIMO radar. The devised system can perform joint range and angle estimation in radar operation, which is currently not achievable in dual-function systems based on PA and MIMO radar. Considering the time-variance of the transmit waveform, we propose a multichannel receiver for the joint system. For radar, 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 maximum ratio combining (MRC) assisted ML detector is introduced to improve the accuracy of the information decoding. Extensive numerical results are presented to verify the feasibility and effectiveness of the proposed system scheme.

Keywords

• Joint radar-communication system
• frequency diverse array (FDA)
• MIMO
• index modulation
• Cramér-Rao bound
• maximum ratio combining (MRC)