John Emmert (Advisor), Fred Garber (Committee Member), Stephen Hary (Committee Member), Raymond Siferd (Committee Member)
Master of Science in Engineering (MSEgr)
The purpose of this research was to investigate the feasibility of using broadband electronic warfare (EW) receivers for Global Position System (GPS) tracking. These are pulse-oriented receivers, typically with input bandwidths of 1 Ghz or larger, and so by definition do not have the same characteristics and processing of continuous wave (CW) receivers like GPS devices, FM radios, etc. For example, the spectral output of the Fast Fourier Transform (FFT) used in broadband signal processing updates on the frequency of the FFT input sample size, versus a CW receiver which updates on a more continuous basis.
The foundation of this potential broadband application of GPS hinges on the ability to accurately detect the GPS Satellite Coarse Acquisition (C/A) Code, which is phase modulated onto the GPS L1 carrier signal. This study uses the high speed Monobit FFT approximation technique developed by Dr. A. Despain  and Dr. Jim Tsui as the core signal processor, of which Dr. Tsui holds patents [2,3]. The cyclical C/A Code FFT spectral bin components are processed and compared to a known good C/A code for a given satellite to determine the accuracy of the correlation.
The novel EW GPS technique developed in this thesis indicates that GPS satellite C/A codes can indeed be reasonably processed with broadband techniques, at least with the Monobit FFT, and that this foundational work can be built upon in the future so that broadband devices can ultimately be used for GPS applications. Synthesizable deliverables include a phase detector, a hardware signal condenser, and a correlation module. A robust Hardware Description Language (HDL) Test Bench, several signal generators, and various Matlab support tools were also developed.
Department or Program
Department of Electrical Engineering
Year Degree Awarded
Copyright 2008, all rights reserved. This open access ETD is published by Wright State University and OhioLINK.