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:
May. 20, 2003
Filed:
Jul. 26, 1999
Alexander Gordon, Morris Plains, NJ (US);
Alex Matusevich, Morris Plains, NJ (US);
Jonathan Tobias, Florham Park, NJ (US);
Sheng-Jen Tsai, Bridgewater, NJ (US);
Robert C. Wang, Mendham Township, NJ (US);
Lucent Technologies Inc., Murray Hill, DE (US);
Abstract
A phase-modulated signal such as a quadrature phase-shift-keyed (QPSK) signal in a wireless communication system is demodulated by frequency demodulating the phase-modulated signal. The phase-modulated signal is separated into first and second copies, the first copy is phase demodulated to generate demodulated symbols, and the second copy is frequency demodulated to generate, e.g., a measure of the instantaneous frequency of the phase-modulated signal. The instantaneous frequency measure is processed to identify one or more symbol transitions, and the identified transitions are used to generate event signals having signature properties (signature events). These signature events are used in traditional Time Difference of Arrival tdoa algorithms to accurately determine position of a mobile unit in the wireless communication system.