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:
Jun. 19, 2001
Filed:
Aug. 07, 1998
Jian Cui, Nepean, CA;
Nortel Networks Limited, Montreal, CA;
Abstract
A demodulator, within a receiver attached to a single antenna, that cancels co-channel interference within a time division multiple access (TDMA) communication system is disclosed. The demodulator takes as input a series of received signals comprising an information signal and a co-channel interference signal, both using the &pgr;/4-differential quadrature phase shift keying (DQPSK) modulation protocol. During a training period, in which the information signals corresponds to a known SYNC word, the demodulator estimates the fading coefficients corresponding to the information and interference signals. After the completion of the training period, the demodulator uses these estimates to generate accurate estimations for future information and interference signals corresponding to future data received signals. Therefore, the information signal has been essentially separated from the co-channel interference signal and can be demodulated with a lower bit error rate (BER) than previous demodulation techniques under these circumstances.