Carrier phase recovery for an adaptive equalizer

An adaptive equalizer for a communications receiver comprising:

• means for demodulating an unequalized data signal;
• an equalizer loop containing a filter coupled to receive demodulated data from said demodulating means, an error signal generator coupled to receive filtered data from said filter, and means responsive to error signals from said error signal generator for updating coefficients for input to said filter;
• a carrier recovery loop comprising a phase detector coupled to receive said filtered data and provide a first phase error signal for controlling said demodulating means;
• and
• means, coupled to receive a second phase error signal from said phase detector, for generating a carrier lock signal when said second phase error signal meets a threshold;
• wherein said error signal generator is responsive to said carrier lock signal for generating error signals from a first coefficient update algorithm when said second phase error signal fails to meet said threshold and for generating error signals from a second coefficient update algorithm when said second phase error signal meets said threshold.

An adaptive equalizer for a communications receiver comprising:

• an adaptive filter for filtering unequalized data representative of coordinates in a constellation pattern;
• an error signal generator for converting filtered data from said filter to error signals based on a first or second coefficient update algorithm;
• means coupled to receive error signals output form said error signal generator for updating coefficients for said adaptive filter;
• a phase detector for converting said filtered data to phase error signals;
• and
• means responsive to said phase error signals for controlling said error signal generator to provide error signals according to said first coefficient update algorithm when a phase error represented by said phase error signals is above a predetermined threshold and to provide error signals according to said second coefficient update algorithm when said phase error is below said predetermined threshold.