Crosstalk mitigation

Abstract

Methods and devices are provided for estimating crosstalk from a legacy line to a vectored line.

What is claimed is: 
     
         1 . A method, comprising:
 estimating crosstalk from at least one first communication line not operating according to a vector standard to at least one second communication line operating according to a vector standard, and   adapting a vectoring based on the estimated crosstalk.   
     
     
         2 . The method of  claim 1 , wherein estimating crosstalk comprises transmitting a probe signal from a central office device on the at least one first communication line. 
     
     
         3 . The method of  claim 2 , further comprising aligning the probe signal with synchronization symbols on the at least one second communication line. 
     
     
         4 . The method of  claim 3 , wherein communication via the at least one first communication line is a multitone communication, wherein sending the probe signal comprises transmitting predetermined data on a subset of tones of the multitone modulation. 
     
     
         5 . The method of  claim 4 , further comprising at least one of adding artificial noise to the tones of the selected tones, exclusion of the tones from a supported set of tones, exclusions of the tones by a mask parameter or excluding the tones from communication by modifying a communication device coupled to the at least one first communication line. 
     
     
         6 . The method of  claim 3 , wherein the probe signal is orthogonal to crosstalk estimation signals transmitted on the at least one second communication line. 
     
     
         7 . The method of  claim 3 , wherein a synchronization signal comprises the probe signal. 
     
     
         8 . The method of  claim 1 , wherein estimating crosstalk comprises estimating crosstalk from the at least one first line to the at least one second line based on uncorrelated data symbols on the at least one first line. 
     
     
         9 . The method of  claim 8 , wherein estimation of crosstalk is performed prior to training of the at least one first line. 
     
     
         10 . The method of  claim 1 , further comprises re-using previously estimated crosstalk. 
     
     
         11 . A communication device comprising a plurality of transceivers, each of the transceivers being configured to be coupled to a plurality of communication lines, and
 a vectoring device coupled to the plurality of transceivers,   at least one of the transceivers being configured to support communication with a non-vector adapted further transceiver,   the communication device being adapted to estimate crosstalk from a legacy line coupled to the non-vector adapted transceiver to at least one vectored line coupled to a vector adapted further transceiver.   
     
     
         12 . The communication device of  claim 11 , wherein a transceiver of the plurality of transceivers coupled to the legacy line is configured to transmit a probe signal on the legacy line. 
     
     
         13 . The communication device of  claim 12 , wherein the transceiver coupled to the legacy line is configured to align the probe signal with synchronization symbols on the at least one vectored line. 
     
     
         14 . The communication device of  claim 13 , wherein the device is configured such that communication via the legacy line and vectored line is a multitone communication, wherein the probe signal comprises predetermined data on a subset of tones of the multitone modulation. 
     
     
         15 . The communication device of  claim 14 , wherein the at least one transceiver is configured to at least one of adding artificial noise to the tones of the selected tones, exclusion of the tones from a supported set of tones, exclusion of the tones by a mask parameter or excluding the tones from communication by modifying a communication device coupled to the at least one first communication line. 
     
     
         16 . The communication device of  claim 13 , wherein the probe signal is orthogonal to crosstalk estimation signals transmitted on the at least one second communication line. 
     
     
         17 . The communication device of  claim 13 , wherein a synchronization signal comprises the probe signal. 
     
     
         18 . The communication device of  claim 11 , wherein the device is configured to estimate crosstalk from the legacy line to the vectored lines based on uncorrelated data symbols on the legacy line. 
     
     
         19 . The communication device of  claim 18 , wherein the device is adapted to estimate crosstalk prior to training of the legacy line. 
     
     
         20 . The communication device of  claim 11 , further being configured to re-use previously estimated crosstalk.