Crosstalk cancellation using sliding filters

摘要

A crosstalk cancellation system and method is disclosed for use in a multi-channel communication system. Crosstalk which couples between channels is cancelled through use of an in-line FFE filter and in-line delay. A cross-connect system associated with each channel includes a cross-connect delay and cross-connect filter. The cross-connect system generates a cancellation signal for each of the channels, which is routed into a junction. The junction subtracts the cancellation signal from the received signal, which has also been delayed and filtered, to remove unwanted cross-talk. During training, cancellation magnitude is monitored at various delay offsets to determine which offset and corresponding filter coefficients, for each delay, maximizes cancellation. The filters are set with filter coefficients that maximize cancellation. The cross-connect delay with the maximum offset is set to zero and its calculated offset amount is established as the in-line delay offset. The other cross-connect delay offsets are adjusted accordingly.

主权项

1. A method for training a crosstalk cancellation system id="REI-00001" date="20151103" that comprises one or more in-line filters, one or more in-line delays, one or more cross-connect filters, and one or more cross-connect delaysid="REI-00001" , id="REI-00002" date="20151103" the method comprising, id="REI-00002" for each channel id="REI-00003" date="20151103" the method comprisingid="REI-00003" :
providing a crosstalk cancellation system comprising one or more in-line filters, one or more in-line delays, one or more cross-connect filters, one or more cross-connect delays and a memory; setting one or more in-line delays and one or more cross-connect delays to zero delay; training the one or more in-line filters; training the one or more cross-connect filters to generate cross-connect filter coefficients; storestoring the cross-connect filter coefficients; continuecontinuing to adapt the one or more in-line filters and store resulting in-line filter coefficients with the cross-connect filter coefficient as filter coefficient sets; establishing an offset in one or more in-line delays; retraining the one or more in-line filters and the one or more cross-talk filters with the established offset to establish new coefficient set; storing the new coefficient set; establishing additional offsets and for each additional offset: retraining the one or more in-line filters and the one or more cross-talk filters to create a filter coefficient set associated with each offset; storing the additional filter coefficients sets associated with each offset; analyzeanalyzing the filter coefficient sets to determine which offset maximizes cancellation to thereby identify a maximum cancellation offset; establishestablishing one or more in-line filters with coefficient set which corresponds to maximum cancellation offset; establishestablishing one or more in-line delays with offset which corresponds to maximum cancellation offset for victim-interferer pair that needs the largest delay to maximize its cancellation; establishestablishing one or more cross-connect filters with a coefficient set which corresponds to maximum cancellation offset; and establishestablishing one or more cross-connect delays with offset which corresponds to maximum cancellation offset.