Ericsson Ab

Stmicroelectronics N.v.

Frank Sjöberg

Mikael Isaksson

Lennart Olsson

Daniel Bengtsson

Gunnar Bahlenberg

Magnus Johansson

Hans Öhman

Hans Ohman

Sarah Kate Wilson

Bo Engström

Per Ödling

Rickard Nilsson

Anders Isaksson

Tomas Stefansson

Goran Okvist

Lis-Marie Ljunggren

Sven-Rune Olofsson

Joachim Johansson

Bo Engstrom

Per Odling

Sven-Göran Ökvist

Tomas Nordström

Göran Ökvist

Richard Nilsson

Per Ola Borjesson

Niklas Grip

Transmitting and receiving arrangements and methods in a Digital Subscriber Line (DSL) system having a plurality of modems and vectored transmission capability. A first part of an available frequency band is reserved for vectored DSL transmission and reception using modems operating in the first part of the frequency band. The remaining, second, part of the available frequency band is reserved for both vectored and non-vectored transmission using modems operating in the second part of the frequency band.

Method and arrangement in a digital subscriber line system

Transmitting and receiving arrangements and methods in a Digital Subscriber Line (DSL) system having a plurality of modems and vectored transmission capability. A first part of an available frequency band is reserved exclusively for vectored DSL transmission and reception using modems operating in the first part of the frequency band. The remaining, second, part of the available frequency band is reserved for both vectored and non-vectored transmission using modems operating in the second part of the frequency band.

The present invention relates to arrangements and methods in a Digital Subscriber Line (DSL) system. The basic idea of the present invention is to reserve a first part of an available frequency band exclusively for vectored DSL transmission and reception. The remaining part of the available frequency band can then be used either for only standard non-vectored transmission or for both for vectored DSL and for standard non-vectored DSL transmission. Therefore, the present invention makes it possible to get the full benefit of vectored transmission, on at least the first part of the frequency band, even if the DSL vector system cannot handle all DSL modems.

The present invention relates to a vectoring chip unit in a DSL system connectable to a plurality of DSL ports of a DSL chip comprising means for receiving data from each of the plurality of DSL ports, means for performing pre-coding/cancellation in order to reduce crosstalk and means for transmitting a result of the precoding/cancellation to the respective DSL port. Preferably, a system is provided comprising a plurality of said vectoring chips, whereby each vectoring chip is adapted to handle pre-coding/cancellation of a predetermined frequency range and the frequency ranges of each vectoring chip are non-overlapping.

Vectored digital subscriber line system having modular vectoring arrangements

Zipper is the time-synchronized frequency-division duplex implementation of discrete multi-tome (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. When all transmitters are time synchronized, the near end cross-talk (NEXT) and near end echoes injected into the received signal are orthogonal to the desired signal. The present invention provides a telecommunications transmission system using zipper and having at least two VDSL systems. Each VDSL system comprises a pair of zipper modems communicating over a cable transmission path. The telecommunications transmission system handles zipper transmission transmitted over the common cable; at least partly mitigates NEXT; and permits transmissions in a first VDSL system which are asynchronous with transmissions in a second VDSL system.

In, or relating to, VDSL

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

A RFI canceller, for use in a subscriber line system using multi-carrier modulation, measures a RFI disturbance in carriers falling within a band of frequencies causing the RFI. The RFI ingress into carriers outside the band of frequencies is estimated, and an error correcting signal derived from the estimation of the RFI ingress is subtracted from a received signal. The subscriber line system may be a VDSL system and the multi-carrier modulation may be DMT. The RFI canceller includes a demodulator for demodulating an incoming data stream to provide a first parallel data stream. A parallel to serial convertor converts the first parallel data stream to a first serial data stream. A digital to analogue convertor converts the first serial data stream to a first analogue signal. An analogue RFI canceller circuit combines the analogue signal with an analogue error correcting signal, to produce a second analogue signal. An analogue to digital convertor converts the second analogue signal to a second serial data signal. A serial to parallel convertor converts the second serial data stream to a second parallel data stream. A modulator modulates the second parallel data stream onto a multiplicity of carriers.

Subscriber line transmission systems

Growing community of inventors

Luleå, Sweden

Frank Sjöberg