Patent ID: 6278741
Filing Date: 2001-08-21
Classification: H04B,H04L

Abstract:
A method for generating a correction command for advancing or delaying the sample timing of a modem front end used to recover data from an incoming QAM baseband signal having maximum/minimum, said method comprising the steps of:(A) sampling said QAM baseband signal;(B) estimating an absolute value of a derivative of said QAM baseband signal separately for a real and an imaginary axis;(C) adding said estimated absolute values of said real and said imaginary derivatives of said QAM baseband signal to develop a resulting signal;(D) multiplying said resulting signal by a uniform weighting function to develop said local error signal;(E) averaging said local error signal over a predetermined time period;and(F) utilizing said averaged local error signal to make a global decision regarding the sampling point position relative to said baseband signal maximum/minimum.