The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 1987
Filed:
Jun. 22, 1984
Albertus M Claessen, Montfoort, NL;
NCR Corporation, Dayton, OH (US);
Abstract
An adaptive hybrid circuit is disclosed for adaptively cancelling a crosstalk component from a transmitter to a receiver in a local station of a local area network. In a preferred embodiment the adaptive hybrid circuit is coupled to a common two-wire transmission line in the network and also between the transmitter and the receiver of the local station. The adaptive hybrid circuit is comprised of a comparator, an integrator and an adjustment circuit. An output signal from the receiver is compared in the comparator with a transmit signal to develop a first signal which causes the integrator to develop a second signal having an amplitude which varies as a function of the states of the first signal. The second signal from the integrator, a transmitter signal, and a composite signal from the transmission line containing a crosstalk component from the transmitter and a received signal component transmitted from a remote station are applied to the adjustment circuit. In the adjustment circuit the transmitter signal is multiplied by the second signal to develop an estimate of the crosstalk component which estimate varies automatically to cancel the crosstalk component in the composite signal for any given transmission line impedance. When the crosstalk component is cancelled, the output of the adjustment circuit only contains the received signal which is detected by the receiver.