The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 2001
Filed:
Dec. 02, 1999
John Louis Spiesberger, Radnor, PA (US);
Other;
Abstract
A detection problem is introduced for a source of some bandwidth and unknown waveform and emission time in the presence of noise of uncertain variance. The signal travels to the receivers along paths whose delays may be unknown. Using a new receiver called a “matched-lag filter,” the presence or absence of the signal is estimated from the auto- and cross-correlation functions of the received signals. The use of correlation functions provides the first stage of gain in signal-to-noise ratio, like a matched filter, because the paths are assumed to be partially coherent with one another. The second stage achieves additional gain by searching only over the physically possible arrangements of signals in the auto- and cross-correlation functions. These stages enable the matched-lag filter to behave like a matched filter within a matched filter. In a simple case, simulations of the matched-lag filter yield probabilities of detection that are, with one and two receivers, 4.5 to 290 times respectively that obtained from the alternative energy detector at a false-alarm probability of 0.001. The matched-lag filter has applications to communications and the detection of broadband signals such as from animals, vehicles, ships, nuclear blasts, and seismic events, and blind estimation of the impulse response of a multipath channel.