Space-Frequency Modulation Radar-Communication and Mismatched Filtering

Increasing congestion has spurred investigations into more efficient utilization of the radio frequency (RF) spectrum while minimizing the volume and weight of the RF equipment. Considering the similarity of radar and communication in both software and hardware, this paper presents a co-design integrated waveform of radar and communication based on the multiantenna system. In this paper, communication data is first transported by utilizing space-frequency modulation on a fixed transmitting frequency set. By using digital beamforming technology in the subarray level, directional communication with cooperative targets in the main lobe can be achieved. However, modulation in space-frequency domain results in high sidelobes in the autocorrelation function. Thus, to acquire an acceptable radar performance, the mismatched filter (MMF) is proposed to realize information defusion and sidelobe suppression. Aiming at reducing the signal-to-noise ratio loss of the MMF process, the filter response is further modified. Finally, numerical simulations assess the effectiveness of the proposed MMF and the Doppler coherency between pulses for clutter cancellation. Simulation results demonstrate the capability and potential of the proposed co-design signal for radar-communication system.