公开(公告)号：EP1131900A1

公开(公告)日：2001-09-12

申请号：EP99963715.0

申请日：1999-11-18

Applicant: STMicroelectronics N.V.

Inventor： SJÖBERG, Frank ,  WILSON, Sarah, Kate ,  NILSSON, Rickard ,  BENGTSSON, Daniel ,  ISAKSSON, Mikael ,  NORDSTRÖM, Tomas ,  ÖDLING, Per ,  BAHLENBERG, Gunnar ,  JOHANSSON, Magnus ,  OLSSON, Lennart ,  ÖKVIST, Sven-Göran

IPC: H04B3/32 ,  H04B3/04

CPC classification number: H04B3/32 ,  H04L5/0007

Abstract: 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 metre cannot transmit data upstream. The present invention provides a VDSL 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. These 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.

公开(公告)号：EP1062760B1

公开(公告)日：2004-11-24

申请号：EP99907994.0

申请日：1999-02-17

Applicant: STMicroelectronics N.V.

Inventor： ISAKSSON, Mikael ,  BENGTSSON, Daniel ,  SJÖBERG, Frank ,  ÖDLING, Per c/o Bo Ödling ,  NILSSON, Rickard ,  BAHLENBERG, Gunnar ,  JOHANSSON, Magnus ,  OLSSON, Lennart ,  ÖKVIST, Göran

IPC: H04L5/06 ,  H04L27/26

CPC classification number: H04L5/143 ,  H04L27/2607 ,  H04L27/2626 ,  H04L27/2647

Abstract: Zipper is a time-synchronized frequency-division duplex implementation of discrete multi tone (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. The Zipper scheme implies that every carrier, in the total set of carriers in the DMT signal, is exclusively chosen to be used for either the up-stream or the down-stream direction. 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 s 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 two VDSL systems employ a common cable. The telecommunications transmission system is adapted to: handle zipper transmissions transmitted over the common cable; at least partly mitigate NEXT; and permit transmissions in a first VDSL system which are asynchronous with transmissions in a second VDSL system.

公开(公告)号：EP1131900B1

公开(公告)日：2003-10-15

申请号：EP99963715.0

申请日：1999-11-18

Applicant: STMicroelectronics N.V.

Inventor： SJÖBERG, Frank ,  WILSON, Sarah, Kate ,  NILSSON, Rickard ,  BENGTSSON, Daniel ,  ISAKSSON, Mikael ,  NORDSTRÖM, Tomas ,  ÖDLING, Per ,  BAHLENBERG, Gunnar ,  JOHANSSON, Magnus ,  OLSSON, Lennart ,  ÖKVIST, Sven-Göran

IPC: H04B3/32 ,  H04B3/04

CPC classification number: H04B3/32 ,  H04L5/0007

公开(公告)号：EP1062760A1

公开(公告)日：2000-12-27

申请号：EP99907994.0

申请日：1999-02-17

Applicant: STMicroelectronics N.V.

Inventor： ISAKSSON, Mikael ,  BENGTSSON, Daniel ,  SJÖBERG, Frank ,  ÖDLING, Per ,  NILSSON, Rickard ,  BAHLENBERG, Gunnar ,  JOHANSSON, Magnus ,  OLSSON, Lennart ,  ÖKVIST, Göran

IPC: H04L5/06 ,  H04L27/26

CPC classification number: H04L5/143 ,  H04L27/2607 ,  H04L27/2626 ,  H04L27/2647

Abstract: Zipper is a time-synchronized frequency-division duplex implementation of discrete multi tone (DMT) modulation. Two communicating Zipper modems transmit DMT symbols simultaneously with a common clock. The Zipper scheme implies that every carrier, in the total set of carriers in the DMT signal, is exclusively chosen to be used for either the up-stream or the down-stream direction. 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 s 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 two VDSL systems employ a common cable. The telecommunications transmission system is adapted to: handle zipper transmissions transmitted over the common cable; at least partly mitigate NEXT; and permit transmissions in a first VDSL system which are asynchronous with transmissions in a second VDSL system.