Device and method for increasing the bandwidth in a line-connected multicarrier system
View Patent ↗The invention relates to a device and a method for increasing the bandwidth in a line-connected multicarrier system, the characteristic properties, estimated by a channel estimator of a transmission channel being interpolated/extrapolated by an interpolating/extrapolating device. An equalizer device performs additional equalization of affected carriers in dependence on these interpolated/extrapolated properties, a bit loading device being adapted in dependence on the additional equalization. In this manner, further carriers are available for the data transmission which increases a bandwidth.
1. A device for increasing the bandwidth in a line-connected multicarrier system, comprising:
a channel estimator to estimate characteristic properties of a transmission channel;
a decision stage to correlate a decision stage input data value with a value of a predetermined set of values of a transmission format;
a bit allocation table to specify an amount of information to be decoded/coded on a carrier of the multicarrier system;
a bit loading device to change the bit allocation table;
a noise variance determining device to drive the bit loading device based on a noise variance prevailing on the carriers;
an interpolation/extrapolation device to interpolate/extrapolate the estimated characteristic properties of the transmission channel; and
an equalizer device to perform additional equalization of carriers in dependence on the interpolated/extrapolated characteristic properties, the bit loading device being driven based on the additional equalization in the equalizer device.
2. The device as claimed in claim 1 , wherein the characteristic properties of the transmission channel represent a phase, the interpolation/extrapolation device represents a phase interpolator/extrapolator, and the equalizer device represents an additional phase equalizer.
3. The device as claimed in claim 1 , wherein the bit loading device is driven during one of an initialization phase and when a data transmission is in progress.
4. The device as claimed in claim 1 , wherein the multicarrier system represents an ADSL or UDSL system.
5. A method for increasing the bandwidth in a line-connected multicarrier system, comprising:
estimating characteristic properties of a transmission channel;
interpolating/extrapolating the estimated characteristic properties of the transmission channel for disturbed carriers;
determining equalizer coefficients for disturbed carriers based on the interpolated/extrapolated characteristic properties;
modifying a bit loading algorithm based on the equalizer coefficients; and
performing the modified bit loading algorithm for specifying an amount of information to be decoded/coded on a carrier of the multicarrier system.
6. The method as claimed in claim 5 , wherein a phase of the transmission channel is estimated and interpolated/extrapolated.
7. The method as claimed in claim 5 , wherein the method is performed during an initialization phase.
8. The method as claimed in claim 5 , further comprising performing equalization of the characteristic properties of the disturbed carriers during a data transmission.
9. The method as claimed in claim 5 , wherein the method is performed in an ADSL or UDSL system.