Stmicroelectronics N.v.

Stmicroelectronics S.a.

Tomas Nordström

Daniel Bengtsson

Mikael Isaksson

Lennart Olsson

Magnus Johansson

Gunnar Bahlenberg

Olivier Isson

Frank Sjöberg

Sarah Kate Wilson

Rickard Nilsson

Sven-Göran Ökvist

Per Ödling

One problem, frequently encountered with VDSL transmission systems, is that upstream FEXT produced by system users having short wires can be very strong. Users having shorter wires get high bit rates whereas users having longer wires get low bit rates. In extreme cases it may happen that users with wire lengths greater than 1000 meter cannot transmit data upstream. The present invention provides a VDST transmission system with a plurality of modems. The modems are located at varying distances from a central station. There is a target bit rate for each modem. That modems on shorter wires have control means for reducing their transmit power. This reduces the FEXT produced by these modems enabling modems on longer wires to transmit at higher bit rates.

VDSL transmission systems

The invention relates to a far-end crosstalk canceling circuit for a digital subscriber line transmission system, the transmission system including a plurality of line termination modems receiving discrete multitone symbols from corresponding network termination modems over a plurality of transmission channels. The invention estimates the modulated data actually transmitted by the network termination modems from the frequency components of the discrete multitone symbols received by the line termination modems and to evaluate the far-end crosstalk as a linear combination of these estimates. Far-end crosstalk cancellation for all the line termination modems is also provided in a centralized manner.

DSL transmission system with far-end crosstalk cancellation

Growing community of inventors

Luleå, Sweden

Tomas Nordström