Dual-Functional Radar Waveforms without Remodulation

Abstract

Dual function radar communication (DFRC) system provides a means to co-existence of radio frequency systems performing active sensing and information transmission to designated users. This paper utilizes waveform diversity to perform radar and communication functionalities simultaneously without modulating radar waveforms. A few categories of diverse waveforms, including frequency diverse, chirp diverse, and phase-coded diverse waveforms, are considered suitable for this application. For each of these categories, a communication symbol corresponds to one waveform in a predefined set or dictionary of waveforms. In this sense, the proposed DFRC system implements a code-shift keying (CSK) strategy for signal embedding. This strategy prevents degradation to the temporal or spectral characteristics of the radar waveforms or any alterations of the radar functions. Further, the coherent processing gain achieved by pulse compression is used in full in decoding communication information conveyed by the radar waveform. We derive the probability of bit error as a function of both signal-to-noise ratio (SNR) and the isolation between the waveforms in the employed waveform dictionary.