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公开(公告)号：JP2001237747A
公开(公告)日：2001-08-31
申请号：JP2000377457
申请日：2000-12-12
Applicant: ST MICROELECTRONICS SA , ST MICROELECTRONICS NV
Inventor： NORDSTROEM TOMAS , BENGTSSON DANIEL , ISSON OLIVIER
Abstract: PROBLEM TO BE SOLVED: To provide a canceller circuit which can eliminate far-edge crosstalks, in a digital subscriber circuit transmission system. SOLUTION: This system includes a pre-compensation means which multiplies a vector S=(Si), where i is equal to 1 to n by a pre-compensation matrix M prior to transmission, so as to obtain a diagonal matrix product H*M. In this example, H is a transmission matrix of plural transmission channels as prescribed by R=H*S and R=(Ri), where i is equal to 1 to n is a vector of discrete multi-tone symbol Ri that is received by a modem. Such a system configuration is attained by a far-edge crosstalk eliminating circuit.
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公开(公告)号：JP2001244855A
公开(公告)日：2001-09-07
申请号：JP2000377458
申请日：2000-12-12
Applicant: ST MICROELECTRONICS SA , ST MICROELECTRONICS NV
Inventor： NORDSTROEM TOMAS , BENGTSSON DANIEL , ISSON OLIVIER
Abstract: PROBLEM TO BE SOLVED: To provide a canceler circuit which can remove far-end crosstalk in a digital subscriber line transmission system. SOLUTION: Modulated data actually sent by a network terminal model are estimated from the frequency components of a discrete multi-tone symbol received by a line terminal modem to evaluate far-end crosstalk as the linear combination of those estimated values. Far-end crosstalk removing circuits for line terminal models are all provided in a centralized system.
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公开(公告)号：DE69907864D1
公开(公告)日：2003-06-18
申请号：DE69907864
申请日：1999-03-05
Applicant: ST MICROELECTRONICS NV , ST MICROELECTRONICS SA
Inventor： ISSON OLIVIER , NORDSTROEM TOMAS
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公开(公告)号：DE69906548D1
公开(公告)日：2003-05-08
申请号：DE69906548
申请日：1999-12-14
Applicant: ST MICROELECTRONICS NV , ST MICROELECTRONICS SA
Inventor： NORDSTROEM TOMAS , BENGTSSON DANIEL , ISSON OLIVIER
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公开(公告)号：DE69907864T2
公开(公告)日：2004-05-06
申请号：DE69907864
申请日：1999-03-05
Applicant: ST MICROELECTRONICS NV , ST MICROELECTRONICS SA
Inventor： ISSON OLIVIER , NORDSTROEM TOMAS
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Patent Agency Ranking
公开(公告)号：DE69906548T2
公开(公告)日：2004-03-04
申请号：DE69906548
申请日：1999-12-14
Applicant: ST MICROELECTRONICS NV , ST MICROELECTRONICS SA
Inventor： NORDSTROEM TOMAS , BENGTSSON DANIEL , ISSON OLIVIER
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公开(公告)号：JP2000299650A
公开(公告)日：2000-10-24
申请号：JP2000059264
申请日：2000-03-03
Applicant: ST MICROELECTRONICS SA , TELIA AB
Inventor： ISSON OLIVIER , NORDSTROEM TOMAS
Abstract: PROBLEM TO BE SOLVED: To obtain a DSL transmission system of simple constitution by setting a period for processing a filter to an at least previously set time length. SOLUTION: An output symbol system S is subtracted from the output of a delay line 80 by a subtracting circuit 82, and a difference signal is supplied to an FIR filter 84 for realizing a transfer function h* for local echo inference. A filter 84 operates only to sampling data corresponding to a delaying time δor the maximum delaying time of a line and infers echo component from the difference between two continuous symbols. However, being a linear filter, the component is equivalent to the difference between the respective echo components of the two symbols. The output of the filter 84 is supplied for an adding circuit 86, and an input symbol S' receiving the influence of a nonlinear echo is simultaneously received. The circuit 86 supplies a desired orthogonal echo signal to a Fast Fourier Transforming(FFT) circuit 18 as an input signal IN'. Then, the filter 84 operates only in a short period at the starting point of each transmission symbol.
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公开(公告)号：DE69723563T2
公开(公告)日：2004-05-13
申请号：DE69723563
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 using orthogonal carriers with high order QAM constellations for the transmission of a plurality of bits per carrier and symbol. The system uses some method for the determination of an inverse channel model to be used in the equalization process. In the frequency domain, this is normally based on an estimate of the channel attenuation and phase for each carrier. A simplified method of equalization is provided which uses data at the symbol carrier input and output to adaptively estimate an inverse channel model.
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公开(公告)号：DE69812850T2
公开(公告)日：2004-01-22
申请号：DE69812850
申请日：1998-02-27
Applicant: ST MICROELECTRONICS NV
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 , NORDSTROEM TOMAS , OLOFSSON SVEN-RUNE , STEFANSSON TOMAS , OEHMAN HANS , OEKVIST GOERAN
Abstract: A mechanism for achieving frame synchronization in the frequency domain. In order to synchronize a receiver with a transmitter, on signal acquisition, the interval in which orthogonality exists is determined. Once this has been achieved, an argument function is calculated from the received frame. This argument function can then be used to improve the synchronization. This system is particularly suitable for use in ADSL and VDSL modems which can be used to give broad band access over copper networks. It is also relevant to broad band transmission in mobile and semi-mobile systems for transmission over radio channels.
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公开(公告)号：AT249118T
公开(公告)日：2003-09-15
申请号：AT97933959
申请日：1997-07-15
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 has a plurality of transceivers, each having a receiver and a transmitter. Data is transmitted between the transceivers by modulating the data onto a multiplicity of carrier waves in the form of multi-bit symbols, wherein each carrier wave constitutes a channel, and wherein the number of bits per symbol (the bit loading), varies between channels and, within a channel, with time, so that each channel has associated therewith a bit loading parameter. In operation, the multi-carrier system is adapted to synchronously update, at the transceivers, the bit loading parameters associated with each channel by transmission of data over a control channel, in that the control channel is established, at system start-up, on a predetermined one of the multiplicity of carrier waves whose identity is known to the transceivers, and in that the control channel is, after start-up, changed from the predetermined channel to a further channel, selected by the first transceiver on the basis of channel characteristics.
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