Method and apparatus for timing recovery in ADSL transceivers under a TCM-ISDN crosstalk environment

摘要

A system used to synchronize the clock frequency of a receiver with that of a transmitter, where both the receiver and transmitter communicate using the ADSL Annex C standard. The transmitter continuously transmits pilot tones to the receiver. The receiver determines the phase error between sequential pilot tone symbols to determine a phase error. The receiver uses the phase error to adjust the receiver clock frequency. However, if the most recently received symbol is subject to near end cross talk or is subject to far end cross talk and is a boundary symbol, the receiver ignores the phase error and does not adjust the receiver clock frequency.