Secure Communications: PHY-Layer Techniques Utilizing Distributed Apertures

Date of Award


Degree Name

Ph.D. in Engineering


Department of Electrical and Computer Engineering


Advisor: Michael C. Wicks


Directional modulation is a physical (PHY) layer security technique which corrupts the modulation format received at non-intended receiver angles while preserving the communication modulation format to an intended receiver. The current state-of-the-art in directional modulation techniques is limited in that information content, however corrupted, remains persistent at all angles and spatial security can only be achieved in angle, but not in range. The spatial diversity afforded through distributed aperture antennas enables the extension of the state-of-the-art in directional modulation technology by fundamentally altering the incident information content as a function of spatial position and enabling limited reception of information content over a region in range and angle. The concept of a spatial "coherence basket" is established in this manuscript through near-field propagation modeling and spatio-temporal simulations to describe the information reception region which can be created through distributed aperture design. Concept effectiveness is demonstrated for digital communications through modeling and simulation and a novel hardware implementation for distributed aperture technology is developed and experimentally demonstrated using Software Defined Radio (SDR) hardware.


Electrical Engineering, PHY Layer Security, Directional Modulation, Distributed Apertures

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Copyright © 2020, author