[cid:image007.jpg@01D93644.CC722910] [Bio-inspired Low Probability of Detection RF Steganography via Joint Radar/Communication Waveform Design Zhiqiang Wu, Ph.D. Wright State University Friday, February 3, 2023 11:00 AM * MSEE 239 Abstract The chirp signal is one of the first bio-inspired signals commonly used in radio frequency (RF) applications where the term chirp is a reference to the chirping sound made by birds. It has since been recognized that birds communicate through such chirping sounds to attract other birds of the same species, to transmit an alarm for specific threats, etc. However birds of a different species, or sometime even birds in a different social group within a species, will be unable to connect a specific meaning to certain calls - they will simply hear a bird chirping. Inspired by such, this talk discusses recent research at Wright State University, in collaboration with Air Force Research Laboratory and Office of Naval Research, on a novel RF steganography scheme to conceal digital communication in linear chirp radar signals. We first provide a review of the linear chirp signal and existing communication systems using chirp waveforms. Next we discuss how to implement the RF steganography and hide digitally modulated communication information inside a linear chirp radar signal to prevent the enemy from detecting the existence of such hidden information. A new modulation called reduced phase shift keying is employed to make the modulated chirp waveform almost identical to the unmodulated chirp signal. Furthermore, variable symbol durations are employed to eliminate cyclostationary features that might otherwise be exploited by enemy to detect the existence of the hidden information. We will also discuss the software defined radio implementation of the proposed scheme and its demonstration in RF and underwater acoustic environments. Bio Dr. Zhiqiang Wu received his B.S. from Beijing University of Posts and Telecommunications in 1993, M.S. from Peking University in 1996, and Ph.D. from Colorado State University in 2002, all in Electrical Engineering. He was an assistant professor at West Virginia University Institute of Technology from 2003 to 2005. He joined Wright State University in 2005 and currently serves as the Brage Golding Distinguished Professor of Electrical Engineering. Dr. Wu has published more than 80 journal papers and 220 papers in total. His research interests include wireless communication, electronic warfare, radar signal processing, big data, and artificial intelligence. His research has been supported by NSF, AFOSR, ONR, AFRL, NASA, DoE, and OFRN. Host Professor Husheng Li , hushing@purdue.edu, (858) 717-7009 .]<mailto:hushing@purdue.edu>