-
公开(公告)号：NO990771D0
公开(公告)日：1999-02-19
申请号：NO990771
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AAKE , BENGTSSON DANIEL , HOKANSSON 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.
-
公开(公告)号：NO990770D0
公开(公告)日：1999-02-19
申请号：NO990770
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AAKE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE
Abstract: A multi-carrier transmission system using orthogonal carriers with high order QAM constellations for the transmission of multiple bits per carrier and symbol. Such systems place high demands on the synchronization of the receiver with the transmitter. The maximum permitted deviation from exact synchronization is usually a small fraction of a sampling interval. A reserve carrier, the pilot carrier, which is given a fixed phase, is usually used as the reference to achieve this high accuracy. The receiver sampling clock oscillator is phase locked to the pilot carrier. It is therefore necessary to estimate the phase of the pilot carrier. Using a bandpass filter to recover the pilot carrier, regardless of the frame structure of the DMT signal, does not eliminate the influence of neighboring carriers on the pilot carrier.
-
公开(公告)号：EE04510B1
公开(公告)日：2005-06-15
申请号：EEP9900423
申请日：1998-03-16
Applicant: TELIA AB
Inventor： THOLIN PER , BAHLENBERG GUNNAR , DILLNER ERIK , JOHANSSON MAGNUS , LJUNGGREN LIS-MARI , TONVALL HARRY , WESTER PER-OLA
Abstract: The invention provides a MPEG-2 broadband multimedia terminal for audiovisual communication, or distribution, including a MPEG-2 encoder, a MPEG-2 decoder, a workstation for the presentation of audio, visual and data signals generated by the MPEG-2 decoder, and a control unit for overall management and control of said terminal. The MPEG-2 encoder and decoder have architectures for implementation of ATM-adapted system layer multiplexing and demultiplexing, respectively. The encoder includes a multiplexing unit for packeting and multiplexing audio and video signals in accordance with MPEG-2 and for generating a MPEG-2 transport stream for application to an ATM Adaption Layer (AAL). The multiplexing unit is adapted to divide each MPEG-2 data packet, in the MPEG-2 transport stream, into a number of separate data packets for application to the AAL and to add a status byte to each of the data packets prior to application to the AAL. The MPEG-2 decoder, wherein MPEG-2 system layer decoding includes demultiplexing of the different elementary streams contained within the system layer, and wherein AAL SAR-PDU payload units, extracted from ATM cells, are converted into MPEG-2 data packets, is adapted to convert the AAL SAR-PDU payload units into MPEG-2 data packets, on a cell basis, as part of the MPEG-2 demultiplexing. The AAL SAR-PDU payload units may each include a status byte which indicates, by means of a VCI, the channel over which an associated cell has been transmitted. The status byte may also indicates if an associated data block contains a MPEG-2 packet header.
-
公开(公告)号：NO994362A
公开(公告)日：1999-11-17
申请号：NO994362
申请日：1999-09-09
Applicant: TELIA AB
Inventor： THOLIN PER , BAHLENBERG GUNNAR , DILLNER ERIK , JOHANSSON MAGNUS , LJUNGGREN LIS-MARIE , TONVALL HARRY , WESTER PER-OLA
CPC classification number: H04N21/2381 , H04L2012/5638 , H04L2012/5654 , H04L2012/5672 , H04L2012/5674 , H04N7/52 , H04N21/23614 , H04N21/2668 , H04N21/4113 , H04N21/4305 , H04N21/4307 , H04N21/4343 , H04N21/4345 , H04N21/4348 , H04N21/4381 , H04N21/64307 , H04Q11/0478
-
公开(公告)号：NO990776L
公开(公告)日：1999-04-30
申请号：NO990776
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON 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.
-
Patent Agency Ranking
公开(公告)号：NO990771L
公开(公告)日：1999-04-30
申请号：NO990771
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON 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.
-
公开(公告)号：NO990769L
公开(公告)日：1999-04-30
申请号：NO990769
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE
Abstract: A multi-carrier transmission system, such as a DMT system. A receiver must be able to recover a sampling clock that is very accurately synchronized to a transmitter sampling clock. Typically, synchronization is achieved by using a reserved carrier, the pilot carrier, which is transmitted with a fixed phase. The receiver sampling clock is then phase locked to the pilot carrier. Frame timing can be recovered by using a correlation technique. Thus an improved method of recovering a sample clock and phase locking the sampling clock to a pilot carrier is provided.
-
公开(公告)号：NO990778L
公开(公告)日：1999-04-29
申请号：NO990778
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE
Abstract: PCT No. PCT/SE97/01461 Sec. 371 Date Jun. 14, 1999 Sec. 102(e) Date Jun. 14, 1999 PCT Filed Sep. 1, 1997 PCT Pub. No. WO98/10556 PCT Pub. Date Mar. 12, 1998A multi-carrier transmission system, particularly a discrete multi-tone (DMT) system. Data is transmitted between two transceivers using a plurality of carriers. The frequency bandwidth of the system is divided between the plurality of carriers. The transmission system is adapted for operation in a heterogeneous network including a number of subscriber equipments having different channel characteristics and coexisting on the same cable. The length of cable for each subscriber terminal varies in relation to its respective location. The transmission system includes an allocation device for allocating the traffic of subscriber equipments having a shorter length of cable to tones starting from a higher frequency band of the system bandwidth.
-
公开(公告)号：NO990777A
公开(公告)日：1999-04-29
申请号：NO990777
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE
CPC classification number: H04L25/03159 , H04L1/0065 , H04L1/0071 , H04L27/2649 , H04L27/2656 , H04L27/2657 , H04L27/2662 , H04L2025/03414 , H04L2025/03522
-
公开(公告)号：NO990775L
公开(公告)日：1999-04-29
申请号：NO990775
申请日：1999-02-19
Applicant: TELIA AB
Inventor： ISAKSSON MIKAEL , JOHANSSON MAGNUS , TONVALL HARRY , OLSSON LENNART , STEFANSSON TOMAS , IHMAN HANS , BAHLENBERG GUNNAR , ISAKSSON ANDERS , IKVIST G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON 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.
-
-
-
-
-
-
-
-
-
Search Results
53
records
(took 0.024 seconds)
