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公开(公告)号：DE69717128T2
公开(公告)日：2003-07-10
申请号：DE69717128
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. A received multi-carrier signal is sampled and digitized before FFT processing. Multi-carrier signals consist of many narrow band carrier waves which convey data via a wide band channel. The amplitude distribution of the sum of all the individual carriers is Gaussian. This means that high amplitudes occur with low probability. At the present time, analog to digital converters have a limited dynamic range. It is therefore normal practice to provide a compromise between cutting and quantization noise. The adverse affects of a course quantization have to be balanced between signal distortions caused by the loss of the low probability high amplitude signals.
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公开(公告)号：DE69717127D1
公开(公告)日：2002-12-19
申请号：DE69717127
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：AT227911T
公开(公告)日：2002-11-15
申请号：AT97939277
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：DE69724625T2
公开(公告)日：2004-06-24
申请号：DE69724625
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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公开(公告)号：DE69722415T2
公开(公告)日：2004-05-06
申请号：DE69722415
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: In certain types ol transmission system using nQ,1M it may be desirable to use a control applications in muIticarrier snrstems with variable bitloading it is particularly desirible that the control channel data be separable from user data when the value of n. i.e the bitloading. or constellation identifier are unknown. Binary data is transmitted using nQAM modulation. The binary data comprises both user data and cointro,l clata. This means that a control channel is superimposed on a user data channel within the same nQAM constellation. Separation of said control data is lacilitated by arranging control data points to have either unique phase, or unique amplitude, values. These unique values are not employed for user data points.
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Patent Agency Ranking
公开(公告)号：DE69724625D1
公开(公告)日：2003-10-09
申请号：DE69724625
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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公开(公告)号：DE69717127T2
公开(公告)日：2003-07-31
申请号：DE69717127
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：DE69815104D1
公开(公告)日：2003-07-03
申请号：DE69815104
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 , LUNGBERG HANS , STEFANSSON TOMAS , BAHLENBERG GUNNAR , HAKANSSON SIWERT , JOHANSSON MAGNUS
Abstract: A VDSL-modem which is divided into an analog part which is placed in an optical node and a digital part which is placed in a local station. The analog part of the VDSL-modem includes an A/D-converter and D/A-converter, a filter, an amplifier, a hybrid/balun, an adaptive noise attenuator, an optical interface, and possibly an echo canceller. The digital part of the modem includes an FFT/IFFT-processor, a synchronizer, an equalizer, an interleaving unit, an error correction unit, a protocol manager, and an optical interface. The VDSL-modem simplifies synchronization of the modem and reduces power consumption in the optical node. A multiplexor function in the optical node in addition is simpler because it need not manage a protocol.
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公开(公告)号：DE69812850D1
公开(公告)日：2003-05-08
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：DE69811716D1
公开(公告)日：2003-04-03
申请号：DE69811716
申请日：1998-11-11
Applicant: ST MICROELECTRONICS NV
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , OLSSON LENNART , STEFANSSON TOMAS , OEHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , OEKVIST GOERAN , LJUNGGREN LIS-MARIE , BENGTSSON DANIEL , OLOFSSON SVEN-RUNE , JOHANSSON JOACHIM , BOERJESSON OLA , GRIP NIKLAS , NILSSON RICHARD , SJOEBERG FRANK , WILSON SARAH , OEDLING PER
Abstract: 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.
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