Synchronizing the operation of multiple equilizers in a digital communications system

摘要

In a dual-duplex system wherein the communications channels have associated propagation delays which are typically different from one another, equalizers are connected to operate upon the signal received from each channel. To synchronize the operation of these equalizers to each other, the coefficients of each equalizer are updated when the training sequence is received from at least one of the communications channels. The sequence of symbol values in the training sequence may either be known or unknown to the receiver prior to transmission. When this sequence is detected, the coefficient updating circuit for each equalizer operates in response to a common reference signal. This reference signal includes a plurality of symbols and the value of each symbol is supplied at the same time to each equalizer coefficient updating circuit. This technique generates coefficients which compensate for propagation delay differences between the communications channels and is applicable to communications systems wherein data is distributed and transmitted through a plurality of communications channels.