Patent ID: 6404825
Filing Date: 2002-06-11
Classification: H04L

Abstract:
A digital radio tuner lock detector that receives an in-phase (I) data signal and a quadrature (Q) data signal to determine carrier frequency and phase lock, comprising:means responsive to the I and Q data signals for computing a signal power estimate and integrating said signal power estimate to provide a threshold signal value; means responsive to the I and Q data signals for computing a frequency error signal and for integrating said frequency error signal to provide an integrated frequency error signal; means for comparing the magnitude of said integrated frequency error signal to said threshold signal value to determine if frequency lock has been achieved and for providing a frequency lock signal indicative thereof; and means responsive to the I and Q data signals, and said frequency lock signal, for computing a phase error signal and integrating said phase error signal to provide an integrated phase error signal, and for comparing the magnitude of said integrated phase error signal to said threshold signal value to determine if phase lock has been achieved, and for providing a phase lock signal indicative thereof when said frequency lock signal is active.