Echo-canceling system and method using echo estimate to modify error signal

A hands-free vehicular radiotelephone comprising:

• a microphone, adapted for mounting in a vehicle for hands-free operation by a vehicle occupant, to convert a first acoustic signal into a first electrical signal;
• a loudspeaker, adapted for mounting in a vehicle for hands-free operation by a vehicle occupant, to convert a second electrical signal into a second acoustic signal;
• means, responsive to said second electrical signal, for adaptively estimating an echo in said second electrical signal to produce an echo estimate electrical signal;
• means for obtaining a difference between said echo estimate electrical signal and said first electrical signal to produce an electrical error signal;
• means responsive to said electrical error signal and to said echo estimate electrical signal, for modifying said electrical error signal based upon said echo estimate electrical signal to produce a modified electrical error signal;
• and
• radiotelephone transmitting means, for transmitting said modified electrical signal to a radiotelephone network.

An echo-canceling method comprising the steps of:

• converting a first acoustic signal into a first electrical signal;
• converting a second electrical signal into a second acoustic signal;
• adaptively estimating an echo in said second electrical signal to produce an echo estimate electrical signal;
• obtaining a difference between said echo estimate electrical signal and said first electrical signal to produce an electrical error signal;
• modifying said electrical error signal based upon said echo estimate electrical signal to produce a modified electrical error signal;
• and
• transmitting said modified electrical error signal to a remote receiving system.

An echo-canceling method for a hands-free vehicular radiotelephone, said hands-free vehicular radiotelephone including a microphone, adapted for mounting in a vehicle for hands-free operation by a vehicle occupant to convert a first acoustic signal into a first electrical signal, and a loudspeaker, adapted for mounting in a vehicle for hands-free operation by a vehicle occupant to convert a second electrical signal into a second acoustic signal, said echo-canceling method comprising the steps of:

• adaptively estimating an echo in said second electrical signal to produce an echo estimate electrical signal;
• obtaining a difference between said echo estimate electrical signal and said first electrical signal to produce an electrical error signal;
• modifying said electrical error signal based upon said echo estimate electrical signal to produce a modified electrical error signal;
• and
• transmitting said modified electrical signal to a radiotelephone network.