A method and apparatus enables echo reduction in a full duplex transceiver system. A replica current is subtracted from a receiver via a first differential circuit path that adaptively matches a time constant associated with a second differential circuit path that connects the receiver with an external...http://www.google.fr/patents/US6836544?utm_source=gb-gplus-shareBrevet US6836544 - Sidestone reduction in full duplex transceivers
