Agere Systems Inc.

Eric John Hansen

Richard Lawrence McDowell

Wenzhe Luo

Zhigang Ma

A data-pattern feedback mechanism is introduced into the peak detection process of an automatic frequency compensation system in a Gaussian Frequency Shift Keying (GFSK) modulated system, providing fast and accurate fine-stage automatic frequency compensation (AFC). Maximum positive and negative peak registers are updated with new values as necessary based on detection during a sequence of identical binary bit values (e.g., during a '00' for detection of maximum negative peak frequency, or during a '11' for detection of maximum positive peak frequency), in a particular data frame. As soon as an initial value is determined for both the maximum positive and negative peak frequencies (e.g., after the first occurrence of a &#x201c;11&#x201d; and a &#x201c;00&#x201d;, in any order), fine-stage automatic frequency compensation can be initiated. Subsequent adjustments to the VCO of the local oscillator will further refine the frequency offset towards the ideal of zero. Quick determination of the maximum positive and negative peak frequencies is made based on data pattern feedback in accordance with the principles of the present invention, allowing for a fast and accurate fine-stage automatic frequency compensation adjustment of a local oscillation clock signal.

Growing community of inventors

Lynchburg, VA, United States of America

Eric John Hansen