Inventors:
Frederick R. Cathers - Baltimore OH
Glenn D. Fowler - Canal Winchester OH
J. Arthur Grandle - Reynoldsburg OH
Ronald Hartung - Gahanna OH
Assignee:
AT&T Corp. - Murray Hill NJ
International Classification:
H04L 2701
G06F 1710
H04B 304
H04B 7005
Abstract:
An adaptive circuit is used in the process of recovering data from a signal received from a communications channel. This circuit scripts or varies its transfer function in response to a first error signal derived from the received signal. This adaptation results in the device's transfer function settling to a converged state. An auxiliary information recovery circuit receives the recovered data and derives auxiliary information therefrom. To avoid the problem of false state convergence, the auxiliary information circuit provides a second error signal which causes the adaptive device to reinitiate the adaptation process. In the disclosed embodiment, the adaptive circuit is an equalizer and the auxiliary information recovery circuit is one which recovers framing information or is an error correction circuit. The inability of the auxiliary information circuit to function properly is used as an indication of false convergence of the adaptive circuit.
