Wideband signal detection and tracking system

Abstract

A system is provided for assisting in the detection and tracking of narrowband signals arriving at an antenna array operating over a wide detection bandwidth and in a crowded RF environment. Since the nature of the detection mission is constrained to be a general search, the system does not attempt to detect signals of interest via matched filtering mechanisms (i.e. training sets), but exploits general properties such as power, frequency, time and angle of arrival. For the purposes of providing sufficient Frequency/Time resolution as well as to avoid array overloading in the detection process, the digitized wideband streaming data is frequency channelized using a sufficiently high revisit rate for the signal set of interest, constrained by the required feature detection accuracy or environment adaption rates. Within each frequency subchannel, efficient array signal subspace tracking techniques are used to separate and track spatially separated cochannel signals. Subspace tracking allows the efficient update of the signal subspace, useful for direction finding and copy applications, as well as determining the number of signals present in a frequency channel. Since the frequency channelization of the detection system may not match that of the detected signal, the combination of Time/Frequency/Space information is used to cluster or group frequency subchannels and provide a higher degree of signal detection capability with an increased robustness against false signal detections.