Practical Receiving Strategy and Radar Waveform Extraction Technology in Radar-Embedded Communications

Radar-embedded communication (REC) systems use a series of radar echoes as a mask to send covert communication signals. In this article, we consider a multiapproach method to improve the reliability of the message reception process in REC systems. First, a match-after-filtering strategy is proposed to improve the overall reliability of message reception. Theoretical analysis and simulation results show that, compared with traditional receiving methods, this strategy can dramatically improve the reliability of message reception. Second, precise radar waveform extraction is necessary for communication waveform construction. To precisely extract the radar waveform at the radio frequency tag, we propose an extraction technique using array processing. Finally, in many REC systems, smooth multiple signal classification algorithms and reiterative super-resolution (RISR) algorithms are used for the direction of arrival (DOA) estimation. We develop an improved RISR algorithm, based on a least squares model, to improve DOA estimation accuracy without increasing the complexity.