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:
Jul. 27, 1999
Filed:
Oct. 25, 1996
Benedict Russell Freeman, Cambridge, GB;
Northern Telecom Limited, Montreal, CA;
Abstract
This invention relates to telecommunications systems. The present invention provides a system and method operable to the cancel interference from digital subscriber line systems. A data signal demodulator having first and second inputs arranged to receive differential data signals and local field RFI signals respectively, wherein a digital adaptive notch filter is formed by DSP means which locates an interferer in the differential signal by adapting its bandwidth and center frequency by adaptation means and wherein the center frequency and bandwidth of the notch filter are used to generate a bandpass filter centered on the interferer and of approximate bandwidth to the interferer; whose output, after processing forms a feedback signal which is sampled, processed, weighted and then combined with the local field RFI input signal of the demodulator, which combined signal is summed with the differential input signal to thereby cancel interference coupled onto the first input.