Patent ID: 6741665
Filing Date: 2004-05-25
Classification: H04B,H04L

Abstract:
An automatic frequency control loop circuit, comprising:a mixer for mixing a local oscillator signal with a received signal to generate a result signal; a frequency detector coupled to the result signal and outputting a loop error signal; a combiner circuit for combining error signals output from a plurality of fingers of a rake receiver with the loop error signal output from the frequency detector to generate a combined loop error signal; a sign detector having an input coupled to an output of said combiner circuit for outputting a sign detector output signal for indicating a sign of the combined loop error signal; control circuitry for controlling a frequency of the local oscillator signal in accordance with the sign detector output signal; and a loop filter partitioned into a first loop filter coupled between the output of the frequency detector and an input to the sign detector, and a second loop filter coupled between an output of the sign detector and an input to the control circuitry.