Patent ID: 6304621
Filing Date: 2001-10-16
Classification: H04B

Abstract:
An apparatus for use in a multi-mode variable rate digital cable receiver, comprising:first means for receiving through the cable carrier signals modulated by information signals in a particular frequency range,second means for reducing the frequency of the carrier signals to a particular intermediate frequency,third means for providing a digital conversion of the signals at the reduced frequency from the second means to obtain digital information signals,band selection filtering means responsive to the digital information signals for providing adjacent channel filtered digital data signals, p1 a variable interpolator responsive to the adjacent channel filtered digital data signals for providing first signals,a complex multiplier responsive to the first signals for providing second signals,a baseband adaptive equalizer responsive to the second signals for selecting, for each of the second signals, an individual one of a plurality of amplitude levels in quadrature amplitude modulation,fourth means responsive to the signals from the baseband adaptive equalizer for operating upon the variable interpolator to provide a sampling of the digital information signals for obtaining the first signals in the middle of the period that each of such digital information signals is produced, andfifth means responsive to the first signals from the baseband adaptive equalizer for operating upon the complex multiplier to maintain the frequency of the second signals at the frequency of the digital information signals.