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公开(公告)号：EP0920758B1
公开(公告)日：2002-12-18
申请号：EP98908382.9
申请日：1998-02-27
Applicant: STMicroelectronics N.V.
Inventor： OLSSON, Lennart , BAHLENBERG, Gunnar , BENGTSSON, Daniel , HAKANSSON, Siwert , ISAKSSON, Anders , ISAKSSON, Lars-Ake , ISAKSSON, Mikael , JOHANSSON, Magnus , LAHTI, Mauritz , LJUNGGREN, Lis-Marie , LUNDBERG, Hans , NORDSTRÖM, Tomas , OLOFSSON, Sven-Rune , STEFANSSON, Tomas , ÖMAN, Hans , ÖKVIST, Göran
CPC classification number: H04L27/2662 , H04L27/2657 , H04L27/2672 , H04L27/2678
Abstract: The present invention relates to a receiver for use in an OFDM type transmission system, in which data is transmitted in frames. Each frame has a cyclic prefix which is a repetition of part of the frame. Control means are provided and the control means controls a sampling oscilator. The control means include estimation means for estimating timing deviations of the sampling clock. The estimation means operates entirely on frequency domain input data.
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公开(公告)号：EP1060612B1
公开(公告)日：2002-11-20
申请号：EP99905407.5
申请日：1999-01-28
Applicant: STMicroelectronics N.V.
Inventor： OLOFSSON, Sven-Rune , OLSSON, Lennart , JOHANSSON, Joachim , ÖHMAN, Hans , ISAKSSON, Mikael , JOHANSSON, Magnus , STEFANSSON, Tomas , BAHLENBERG, Gunnar , ISAKSSON, Anders , ÖKVIST, Göran , LJUNGGREN, Lis-Marie , BENGTSSON, Daniel
IPC: H04M11/00
CPC classification number: H04M11/062
Abstract: When delivering a broadband service, such as xDSL, without inband POTS, it is necessary to separate the analogue POTS signal and the xDSL signal from each other at both the CO (Central Office) and the CP (Customer's Premises). This can be achieved by using an active POTS splitter. The present invention incorporates test functionality for the line between the CP and the CO, or ONU (Optical Network Unit), in the POTS splitter. This enables two-sided measurements on the line, both during installation and during operation. The measurements are performed at the CO and upon request, or when the test device automatically sends a test message/signal. In this way there is no need for field technicians at the CP side. The POTS splitter can have a unique identity code that is transmitted to the CO each time a test is started, or on receipt of a request from the CO.
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公开(公告)号：EP0992138B1
公开(公告)日：2002-08-28
申请号：EP98929976.3
申请日：1998-06-10
Applicant: STMicroelectronics N.V.
Inventor： OLOFSSON, Sven-Rune , JOHANSSON, Joachim , ISAKSSON, Mikael , ÖHMAN, Hans , BENGTSSON, Daniel , OLSSON, Lennart , ISAKSSON, Anders , ÖKVIST, Göran , LJUNGGREN, Lis-Mari , LUNDBERG, Hans , STEFANSSON, Tomas , BAHLENBERG, Gunnar , HAKANSSON, Sivert , JOHANSSON, Magnus
IPC: H04L7/08
CPC classification number: H04N1/0035 , H04J3/0644
Abstract: The invention relates to an arrangement for synchronization of nodes in VDSL-systems, or more exactly, synchronization of optical VDSL-nodes (2) which share a common part of a cable in the access network between the subscribers (3) and the local station (1). The invention provides a time synchronization towards an external system (7), 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 respective node includes a receiver (6) for a synchronization signal and an internal oscillator with high stability to deliver a stable clock signal.
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Patent Agency Ranking
公开(公告)号：EP1031199B1
公开(公告)日：2003-02-26
申请号：EP98956052.9
申请日：1998-11-11
Applicant: STMicroelectronics N.V.
Inventor： ISAKSSON, Mikael , JOHANSSON, Magnus , OLSSON, Lennart , STEFANSSON, Tomas , ÖHMAN, Hans , BAHLENBERG, Gunnar , ISAKSSON, Anders , ÖKVIST, Göran , LJUNGGREN, Lis-Marie , BENGTSSON, Daniel , OLOFSSON, Sven-Rune , JOHANSSON, Joachim , BÖRJESSON, Per, Ola , GRIP, Niklas , NILSSON, Richard , SJÖBERG, Frank , WILSON, Sarah , ÖDLING, Per
CPC classification number: H04L25/10 , H04B1/123 , H04L27/2647
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5.发明授权
公开(公告)号：EP1084546B1
公开(公告)日：2003-01-22
申请号：EP99928289.0
申请日：1999-05-11
Applicant: STMicroelectronics N.V.
Inventor： JOHANSSON, Magnus , OLSSON, Lennart , BAHLENBERG, Gunnar , BENGTSSON, Daniel , ISAKSSON, Mikael , OLOFSSON, Sven-Rune , ÖKVIST, Sven, Göran
CPC classification number: H04L25/03159 , H04L27/2655 , H04L2025/03414 , H04L2025/03522 , H04L2025/03617
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6.发明公开
公开(公告)号：EP1084546A1
公开(公告)日：2001-03-21
申请号：EP99928289.0
申请日：1999-05-11
Applicant: STMicroelectronics N.V.
Inventor： JOHANSSON, Magnus , OLSSON, Lennart , BAHLENBERG, Gunnar , BENGTSSON, Daniel , ISAKSSON, Mikael , OLOFSSON, Sven-Rune , ÖKVIST, Sven, Göran
CPC classification number: H04L25/03159 , H04L27/2655 , H04L2025/03414 , H04L2025/03522 , H04L2025/03617
Abstract: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The internal parameters on which such equalizers operate information that defines a time delay between the transmitter and receiver sampling clock. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer accepting time differences which should be corrected by operation of the sample clock controller. The method of the present invention incorporates a modified algorithm for updating the equalizer's parameters. The present invention may be used in, for example, ADSL and VDSL systems employing DMT which have relatively stationary channels. The principle, however, has general application and may be used, with advantage, in mobile and semi-mobile systems such as DECT and GSM.
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公开(公告)号：EP0990341B1
公开(公告)日：2003-05-28
申请号：EP98928780.0
申请日：1998-06-10
Applicant: STMicroelectronics N.V.
Inventor： OLOFSSON, Sven-Rune , JOHANSSON, Joachim , ISAKSSON, Mikael , ÖHMAN, Hans , BENGTSSON, Daniel , OLSSON, Lennart , ISAKSSON, Anders , ÖKVIST, Göran , LJUNGGREN, Lis-Mari , LUNGBERG, Hans , STEFANSSON, Tomas , BAHLENBERG, Gunnar , HAKANSSON, Siwert , JOHANSSON, Magnus
IPC: H04M11/06
CPC classification number: H04M11/062
Abstract: The invention relates to a new type of VDSL-modems where the VDSL-modem is divided into on one hand an analog part which is placed in the optical node, and on the other a digital part which is placed in the local station. The analog part of the VDSL-modem consists of A/D-converter and D/A-converter, filter, amplifier, hybrid/balun, adaptive noise attenuator, optical interface and possibly echo canceller. The digital part of the modem consists of an FFT/IFFT-processor, a synchronizer, an equalizer, an interleaving unit, an error correction unit, a protocol manager, and an optical interface. The invention simplifies i.a. synchronization of the modems and reduces the power consumption in the optical node. The multiplexor function in the optical node in addition will be simpler because it need not manage a protocol.
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公开(公告)号：EP0920765B1
公开(公告)日：2003-04-02
申请号：EP98908383.7
申请日：1998-02-27
Applicant: STMicroelectronics N.V.
Inventor： OLSSON, Lennart , BAHLENBERG, Gunnar , BENGTSSON, Daniel , HAKANSSON, Siwert , ISAKSSON, Anders , ISAKSSON, Lars-Ake , ISAKSSON, Mikael , JOHANSSON, Magnus , LATHI, Mauritz , LJUNGGREN, Lis-Marie , LUNDBERG, Hans , NORDSTRÖM, Tomas , OLOFSSON, Sven-Rune , STEFANSSON, Tomas , ÖHMAN, Hans , ÖKVIST, Göran
CPC classification number: H04L27/2662 , H04L27/2657 , H04L27/2672 , H04L27/2678
Abstract: With OFDM systems the frequency domain data is the Fourier transform of the received time domain OFDM frames. The time domain frames must be sampled, at the receiver, in synchronism with the transmitter, so that each received frame contains data from only a single transmitted frame. It is vital for this synchronism to be maintained in order to maintain the orthogonality of the frames. A typical multi-carrier system, of the OFDM type, which uses a cyclic prefix permits orthogonality to be maintained when there is a small deviation from exact frame synchronisation. Because the signalling interval includes both an entire frame and the cyclic prefix, which is a repetition of part of the frame, a frame sampled within the signalling interval will contain data from only one frame. Since the signalling interval is greater than the frame period, this gives some leeway in frame alignment. The present invention provides a mechanism for achieving frame synchronisation, in the frequency domain, by utilising this fact. The first step in synchronising a receiver with a transmitter, on signal acquisition, is to determine the interval in which orthogonality exists. Once this has been achieved an argument function is calculated from the received frame. This argument function can then be used to improve the synchronisation. The present invention is particularly suitable for use in ADSL and VDSL modems which can be used to give broadband access over copper networks. The invention is also of relevance to broadband transmission in mobile and semi-mobile systems for transmission over the radio channels.
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