Blind signal separation and equalization of full-duplex amplitude

Abstract

An apparatus for blind signal separation and equalization of PAM signals on a full duplex transmission line is capable of successfully extracting and recovering the respective signalling components of a full-duplex wireline digital data link without having to disturb the link during its use (e.g. as by interrupting service to sever the link in order to install a line coupling device, such as a modem or attenuator pad to signal monitoring equipment) and without having to generate PN or other training sequences. A full-duplex wireline bridge device comprises a signal characteristic monitoring device that is capable of monitoring the link and providing respective output signals representative of the respective unidirectional signal components being transmitted simultaneously in opposite directions along the link. A directional signal separator, comprised of a voltage probe and a current probe, each of which can be coupled to the link without severing the link or otherwise disrupting ongoing communications, couples the signal characteristic monitoring device to the link. The signal processing device is operative to controllably combine the outputs of the voltage and current probes and provides respective output signals that are representative of the desired unidirectional signal components. The communications link may be either a single wire transmission line or a two wire balanced transmission line. In the latter instance individual probes of pairs of voltage and current probes are coupled to respective portions of the two wire balanced transmission line.