Data processing for real-time wireless passive radar

The use of passive radar to exploit the vast numbers of wireless transmitters of opportunity in today's congested signal environments has the potential to be a high impact technology with global reach. However the computationally demanding processing associated with high sample rate cross correlation and interference suppression have resulted in lab systems where the data are recorded in-situ, and processed offline. In this paper we present a prototype wireless passive radar system based on a software defined radio architecture that operates in real-time. The system is built on the Universal Software Radio Peripheral (USRP) hardware platform running on LabVIEW™. We explain how real-time operation for the high-bandwidth signals is realised using both efficient cross-ambiguity signal processing and through pipelined data processing, and present experimental results illustrating the system's ability to perform real-time through-wall detection of personnel targets. The system also outputs a target Doppler history which could be useful for target characterization.