Patent ID: 6965753

Claim:
Apparatus for Doppler correction in a wireless communications system, wherein signals transferred within the system to receiving user terminals experience a Doppler effect that varies over time in relation to a user terminal position, comprising: a first frequency synthesizer for generating a carrier signal for the transfer of data that is oscillating at a rate responsive to a first input; a counter coupled to said first input for generating a Doppler compensation signal having a predetermined rate of change as Doppler changes over time, said counter having a clock input; a second frequency synthesizer coupled to said clock input for generating a clock signal oscillating at a rate responsive to a rate input; a rate input signal generator outputting a rate input signal coupled to said second frequency synthesizer rate input so as to adjust said rate input over time so that said Doppler compensation signal is a time varying magnitude signal with a slope that varies at a changing rate over time as to compensates for said Doppler effect at varying rates as it changes over time; and wherein said counter is configured to have an increment value that is held substantially constant, and variations in the rate at which the counter increments in response to said second frequency synthesizer output varies the slope of said Doppler compensation signal.