Stmicroelectronics N.v.

Lis-Mari Ljunggren

Mikael Isaksson

Lennart Olsson

Daniel Bengtsson

Gunnar Bahlenberg

Magnus Johansson

Anders Isaksson

Tomas Stefansson

Sven-Rune Olofsson

Joachim Johansson

Goran Okvist

Hans Ohman

Siwert Hakansson

Hans Lundberg

Sivert H&aring;kansson

Hans Lungberg

Hans &Ouml;hman

G&ouml;ran &Ouml;kvist

A VDSL-modem which is divided into an analog part which is placed in an optical node and a digital part which is placed in a local station. The analog part of the VDSL-modem includes an A/D-converter and D/A-converter, a filter, an amplifier, a hybrid/balun, an adaptive noise attenuator, an optical interface, and possibly an echo canceller. The digital part of the modem includes an FFT/IFFT-processor, a synchronizer, an equalizer, an interleaving unit, an error correction unit, a protocol manager, and an optical interface. The VDSL-modem simplifies synchronization of the modem and reduces power consumption in the optical node. A multiplexor function in the optical node in addition is simpler because it need not manage a protocol.

VDSL modem divided into a digital and an analog part

An arrangement for synchronization of nodes in VDSL-systems, or more exactly, synchronization of optical VDSL-nodes which share a common part of a cable in the access network between subscribers and a local station. A time synchronization is provided towards an external system, for instance GPS, which gives a time reference by which the different nodes can be synchronized. The synchronization reduces the near end cross-talk between the VDSL-systems in the different nodes. Preferably, each respective node includes a receiver for a synchronization signal and an internal oscillator with high stability to deliver a stable clock signal.

Arrangement for synchronization of nodes in VDSL-systems

Growing community of inventors

Lulea, Sweden

Lis-Mari Ljunggren