Patent ID: 6144844
Filing Date: 2000-11-07
Classification: H03J

Abstract:
A system for receiving a signal in a received frequency and shifting the received frequency to become a desired frequency, the system comprising:a. a controllable oscillator for generating a first internal frequency,b. a frequency estimating unit connected to said controllable oscillator,c. a first frequency shift unit, connected to said controllable oscillator and to said frequency estimating unit, for shifting said received frequency according to said first internal frequency, thereby obtaining an initially shifted frequency; andd. a second frequency shift unit connected to said first frequency shift unit and said frequency estimating unit for shifting said initially shifted frequency,e. said frequency estimating unit including:f. means for determining a total frequency shift value from said desired frequency, said received frequency and said first internal frequency;g. means for determining a first frequency shift value and a second frequency shift value from said total frequency shift value,h. means for providing a first frequency change command to said controllable oscillator, so as to correct said first internal frequency according to said first frequency shift value, andi. means for providing a second frequency change command to said second frequency shift unit, so as to shift said initially shifted frequency according to said second frequency shift value.