Abstract: A full duplex communications apparatus, having at each of a plurality of modem stations a transmitter and a receiver circuitry communicating with a two-wire system, receives signals having both a noise free signal component and a noise signal component. The noise signal component includes a far end echo signal which tends to corrupt and distort the received signal hence increasing the error rate. A method and apparatus for reducing the effect of the far end echo signal at the receiver, in particular a receiver using quadrature detection and equalization circuitry, provide a far end echo cancellation circuitry responsive to error signals generated by the receiver decision circuitry. The cancellation circuitry uses a synchronized reference signal from the transmitter of the station.