Ambiguity Function Analysis and Direct-Path Signal Filtering of the Digital Audio Broadcast (DAB) Waveform for Passive Coherent Location (PCL)

摘要

This research presents an ambiguity function analysis of the digital audio broadcast (DAB) waveform and one signal detection approach based on signal space projection techniques that effectively filters the direct-path signal from the receiver target channel. Currently, most Passive Coherent Location (PCL) research efforts are focused and based on frequency modulated (FM) radio broadcasts and analog television (TV) waveforms. One active area of PCL research includes the search for new waveforms of opportunity that can be exploited for PCL applications. As considered for this research, one possible waveform of opportunity is the European digital radio standard DAB. For this research, the DAB performance is analyzed for application as a PCL waveform of opportunity. For this analysis, DAB ambiguity function calculations and ambiguity surface plots are created and evaluated. Signal detection capability, to include characterization of time-delay and Doppler-shift measurement accuracy and resolution, is investigated and determined to be quite acceptable for the DAB waveform.