Improved Information Embedding for Frequency Hopping-Based MIMO DFRC System

Dual function radar communication (DFRC) system, which treats the radar as the primary modality and embeds information into the transmitted waveforms, is proposed recently to solve the problem of spectrum congestion. In this letter, we propose an improved information embedding scheme for a frequency hopping (FH) based multiple-input multiple-output (MIMO) DFRC system. First, we develop an FH matrix construction method by taking the radar ambiguity function (AF) into consideration. The constructed FH matrix is able to generate FH waveforms with superior radar detection performance. Then, an offset quadrature phase-shift keying (OQPSK) modulated communication waveform is presented to alleviate the spectral leakage issue caused by canonical modulation schemes, which together with the FH waveform, forms the transmit waveform of the considered DFRC system. Simulation results verify that the proposed scheme achieves lower AF sidelobe levels (SLLs) and better spectral containment as compared with the state-of-the-art.