Patent ID: 6876696

Claim:
A method of operating a dual-duplex communications system having A and B channel transmitters in a first dual transceiver operatively coupled through A and B loops to corresponding A and B channel receivers in a second dual transceiver, the A and B channel receivers including respective A and B channel equalizers, the method comprising the steps of: a. operating the system in a training mode to initialize timing synchronization between the first and second transceivers, wherein the training mode includes the steps of directing identical channel training data to the respective A and B channel transmitters in the first transceiver, wherein the training data includes a sequence of symbols, concurrently transmitting the training data across the A and B loops to the A and B channel receivers in the second transceiver training the A channel equalizer in the A channel receiver using decision directed training; detecting the sequence of symbols at the output of a first descrambler coupled to the A channel receiver; copying the detected sequence of symbols as contents of the first descrambler to a training scrambler such that the training scrambler is driven by the known sequence of symbols: training the first equalizer and the second equalizer with the output of the training scrambler using table directed training: and b. switching the system to operate in a data mode.