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. 21, 2003
Filed:
Jun. 29, 1999
John E Hudson, Stansted, GB;
Nortel Networks Limited, St. Laurent, CA;
Abstract
The present invention provides a method whereby an adaptive equaliser is applied to the terminal (mobile) receivers in a cellular radio CDMA system whose purpose is to minimise the mutual interference between users sharing the same radio channel. The application relevant to third generation cellular systems which consist of UTRA (or WBCDMA) in Europe and CDMA2000 in the USA (or future merged standards variants of these systems), and has a special application to the time domain duplex (TDD) mode of these systems. An algorithm is provided whereby the equaliser is adapted to conform to some recognised optimality criterion which is known to lead to a minimum mutual interference situation. One method is the constrained minimum output finite impulse response (FIR) digital filter power condition, but the technique is not limited to this criterion. The method reduces the computation load of a digital filter by selecting a sparse subset of delay line taps which are actively weighted and used as a filter. The rest of the delay line taps are ignored. The active subsets are optimized.