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公开(公告)号：DE69904026D1
公开(公告)日：2003-01-02
申请号：DE69904026
申请日：1999-01-28
Applicant: ST MICROELECTRONICS NV
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公开(公告)号：DE69717285D1
公开(公告)日：2003-01-02
申请号：DE69717285
申请日：1997-09-01
Applicant: ST MICROELECTRONICS NV
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , OEHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , OEKVIST GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AKE , BENGTSSON DANIEL , HAKANSSON SIWERT , WEN YE
Abstract: A multi-carrier transmission system such as a DMT based VDSL system. The system uses orthogonal carriers with high order QAM constellations for the transmission of multiple bits per carrier and symbol. This estimate includes digital receiver and transmitter units with the receiver unit including a symbol detection unit. This system is adapted to determine a parameter for each single carrier with the parameter being indicative of a deviation of a received signal from a corresponding constellation point. It compares the parameter with an upper lower limit and if the parameter is outside the limits, changes the constellation used to modulate the carrier to a neighboring constellation. The symbol detection unit may be used to determine a parameter such as the ratio d2/sigma2, where d is the shortest distance between neighboring constellations, sigma is a standard deviation and sigma2 is the variance of the deviations of the input and output signal values of the symbol detection unit.
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公开(公告)号：AT227912T
公开(公告)日：2002-11-15
申请号：AT97937936
申请日：1997-09-01
Applicant: ST MICROELECTRONICS NV
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , OEHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , OEKVIST GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AKE , BENGTSSON DANIEL , HAEKANSSON SIWERT , WEN YE
Abstract: A two-way multi-carrier transmission system, such as a DMT system. If there are dynamic changes in the transmission parameters, synchronization must be maintained between the transmitter and the receiver when the transmission parameters changed. The first stage of such a process requires that the changes of parameter be notified by one transceiver to others involved in an active communication process over a slow transmission channel such as the control channel. Subsequently, the synchronization transceiver is adjusted simultaneously, i.e., from a predetermined DMT symbol. Such adjustments in time synchronization must be achieved with a minimum of overhead.
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公开(公告)号：DE69807486D1
公开(公告)日：2002-10-02
申请号：DE69807486
申请日：1998-06-10
Applicant: ST MICROELECTRONICS NV
Inventor： OLOFSSON SVEN-RUNE , JOHANSSON JOACHIM , ISAKSSON MIKAEL , OEHMAN HANS , BENGTSSON DANIEL , OLSSON LENNART , ISAKSSON ANDERS , OEKVIST GOERAN , LJUNGGREN LIS-MARI , LUNDBERG HANS , STEFANSSON TOMAS , BAHLENBERG GUNNAR , HAKANSSON SIVERT , JOHANSSON MAGNUS
Abstract: 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.
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公开(公告)号：DE69912148T2
公开(公告)日：2004-07-08
申请号：DE69912148
申请日：1999-11-18
Applicant: ST MICROELECTRONICS NV
Inventor： SJOEBERG FRANK , WILSON KATE , NILSSON RICKARD , BENGTSSON DANIEL , ISAKSSON MIKAEL , NORDSTROEM TOMAS , OEDLING PER , BAHLENBERG GUNNAR , JOHANSSON MAGNUS , OLSSON LENNART , OEKVIST SVEN-GOERAN
IPC: H04J11/00 , H04B3/04 , H04B3/32 , H04L29/10 , H04M20060101
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Patent Agency Ranking
公开(公告)号：DE69909292T2
公开(公告)日：2004-04-22
申请号：DE69909292
申请日：1999-10-13
Applicant: ST MICROELECTRONICS NV , ST MICROELECTRONICS SA
Inventor： ISAKSSON MIKAEL , MESTDAGH DENIS JULIEN GILLES , OLSSON LENNART
Abstract: In a DMT telecommunciations transmission system having at least two VDSL systems, each comprising a pair of modems, and belonging to a single binder group common to both VDSL systems, a method is described for keeping DMT frames aligned to the same frame timing. In this way, orthogonality holds and adjacent carriers can be used for different transmission directions without an capacity loss due to NEXT cross-talk. The steps are: estimating the time mis-alignment and power of cross-talk DMT signals added to a received DMT signal. The estimate is used by the modem to synchronise its own frame timing to a main cross-talker's frame timing auto-correlation is used on the received signal and a delayed copy of the received signal correlation maxima determine the frame boundaries of different DMT components of the received signal.
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公开(公告)号：DE69910015D1
公开(公告)日：2003-09-04
申请号：DE69910015
申请日：1999-05-11
Applicant: ST MICROELECTRONICS NV
Inventor： BOERJESSON OLA , ISAKSSON MIKAEL , OEDLING PER , BENGTSSON DANIEL , BAHLENBERG GUNNAR , JOHANSSON MAGNUS , OLSSON LENNART , OEKVIST GOERAN
IPC: H03M1/12
Abstract: A circuit, for digitizing an analogue signal includes an analogue to digital converter, a clip processor adapted to estimate a value for clipped digital signal samples, and a buffer adapted to dynamically store a plurality of digitized samples produced by the analogue to digital converter. The clip processor is adapted to read digitized samples from the buffer and replace clipped digitized samples with the estimated values, thereby mitigating the effects of clipping in an output of the circuit.
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公开(公告)号：DE69717122T2
公开(公告)日：2003-08-21
申请号：DE69717122
申请日：1997-09-01
Applicant: ST MICROELECTRONICS NV
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , OEHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , OEKVIST GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AKE , BENGTSSON DANIEL , HAKANSSON SIWERT , WEN YE , OEDLING PER
Abstract: A multi-carrier transmission system such as a DMT system. Channel information is transmitted between two transceivers using a plurality of sub-carriers modulated with symbols, each of which represents a multiplicity of bits. Each of the transceivers includes a receiver and a transmitter in which a fixed maximum value was determined for the number of bits for each symbol and in which the system is adapted to determine the bit capacity per symbol of each of the plurality of sub-carriers and to increase the number of bits represented by a symbol transmitted over those sub-carriers having a capacity less than a fixed maximum value to the maximum value by the addition of channel coding bits. The fixed maximum value for the number of bits for each symbol may be determined on the basis of the bit capacity of that one of the sub-carriers having the highest theoretical bit capacity may be at least as large as the theoretical bit capacity.
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公开(公告)号：DE69909292D1
公开(公告)日：2003-08-07
申请号：DE69909292
申请日：1999-10-13
Applicant: ST MICROELECTRONICS NV , ST MICROELECTRONICS SA
Inventor： ISAKSSON MIKAEL , MESTDAGH DENIS JULIEN GILLES , OLSSON LENNART
Abstract: In a DMT telecommunciations transmission system having at least two VDSL systems, each comprising a pair of modems, and belonging to a single binder group common to both VDSL systems, a method is described for keeping DMT frames aligned to the same frame timing. In this way, orthogonality holds and adjacent carriers can be used for different transmission directions without an capacity loss due to NEXT cross-talk. The steps are: estimating the time mis-alignment and power of cross-talk DMT signals added to a received DMT signal. The estimate is used by the modem to synchronise its own frame timing to a main cross-talker's frame timing auto-correlation is used on the received signal and a delayed copy of the received signal correlation maxima determine the frame boundaries of different DMT components of the received signal.
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公开(公告)号：DE69904026T2
公开(公告)日：2003-07-17
申请号：DE69904026
申请日：1999-01-28
Applicant: ST MICROELECTRONICS NV
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