Patent ID: 9614582
Date: 2017-04-04
CPC Classifications: H04B,H04M

Claim:
1. A method implemented in a time division duplexing (TDD) orthogonal frequency-division multiplexing (OFDM) communication system where a vectoring technique is used to cancel the Far-End-Crosstalk as described in ITU-T G.9701 (G.fast), comprising: establishing, by a first communication device having a plurality of transmitting ports transmitting in a downstream direction, communication with a plurality of second communication devices which are connected to at least one or all of the plurality of transmitting ports of the first communication device by a crosstalk-coupled channel forming a vectored group, wherein a precoder in the first communication device injects compensation signals to the plurality of transmitting ports so that signals received at the second communication devices are crosstalk-free; performing, by the first communication device, estimation of a residual noise to derive signal-to-noise ratio (SNR) loss for each carrier of one or more carriers with respect to at least one transmitting port of the plurality of transmitting ports of the first communication device, wherein the residual noise is an increased crosstalk noise experienced by one of the second communication devices when one or more other transmitting ports of the first communication device are switched off; and adapting, by the first communication device and the one of the second communication devices, to the residual noise during symbol positions where the one or more other transmitting ports are switched off by using one or more bit-loading tables that are different from each other and different from a perfect bit-loading table which is derived from an assumption of a complete crosstalk cancellation in the vectored group.