Patent ID: 6192088
Filing Date: 2001-02-20
Classification: H04L

Abstract:
A carrier recovery system for use in a demodulator comprising:a complex filter adapted to be supplied with signals representative of an in-phase component and a quadrature-phase component of an incoming signal for generating a phase error signal, said complex filter including a first mode of operation that is a relatively rapid acquisition mode and a second mode of operation and a second mode of operation that is a significantly slower tracking mode than said first mode;a complex multiplier for generating a demodulated version of said in-phase component including an amplitude value and a demodulated version of said quadrature-phase component including an amplitude value;said complex filter generating a first average value of said amplitude value of said demodulated version of said in-phase component and a second average value of said amplitude value of said demodulated version of said quadrature-phase component; andcontrol apparatus for controllably switching said complex filter from said first mode of operation to said second mode of operation in accordance with prescribed criteria.