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:
Dec. 07, 1999
Filed:
Jul. 01, 1997
Mark C Sullivan, Annandale, VA (US);
Information Systems Laboratories, Inc., San Diego, CA (US);
Abstract
A wireless system for locating a signal emitter includes at least three base stations for receiving the emitter signal, and a central processing site for converting information from the received signals into range estimates. Specifically, an antenna array at each base station for receives the emitter signal, and a beamformer isolates the direct path component of this received signal from interference and multi-path signals using cyclic phase minimizer techniques. In operation, an extractor is used to separate a cyclostationary feature from the direct path component of the emitter signal, and the cyclostationary feature is identified in an absolute time reference. The identified cyclostationary feature is then passed to the central processing site. At the central processing site, phase delay characteristics of the cyclostationary features from all participating base stations are compared with each other to obtain phase difference measurements. These phase difference measurements are then converted into differential range estimates for locating the emitter.