Patent search ap:("TELIA AB") AND inv:"TONVALL HARRY" Page 3

21.

发明专利
未知

公开(公告)号：NO990772L

公开(公告)日：1999-04-29

申请号：NO990772

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

IPC: H04L27/34 , H04J11/00 , H04L1/00 , H04L27/26 , H04M3/00 , H04M11/00 , H04L5/06

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.

22.

发明专利
未知

公开(公告)号：NO990770L

公开(公告)日：1999-04-29

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 G RAN , LJUNGGREN LIS-MARIE , NORDSTR M TOMAS , ISAKSSON LARS-KE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE

IPC: H04L27/34 , H04J11/00 , H04L1/00 , H04L27/26 , H04M3/00 , H04M11/00 , H04L5/06

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.

23.

发明专利
未知

公开(公告)号：NO990778D0

公开(公告)日：1999-02-19

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 GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AAKE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE

IPC: H04J11/00 , H04B3/00 , H04L27/26 , H04M3/00 , H04M11/00 , H04L

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.

24.

发明专利
未知

公开(公告)号：NO990776D0

公开(公告)日：1999-02-19

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 GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AAKE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE

IPC: H04L27/34 , H04J11/00 , H04L1/00 , H04L27/26 , H04M3/00 , H04M11/00 , H04L

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.

25.

发明专利
未知

公开(公告)号：NO990769D0

公开(公告)日：1999-02-19

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 GOERAN , LJUNGGREN LIS-MARIE , NORDSTROEM TOMAS , ISAKSSON LARS-AAKE , BENGTSSON DANIEL , HOKANSSON SIWERT , WEN YE

IPC: H04J11/00 , H04L1/00 , H04L7/033 , H04L27/26 , H04M3/00 , H04M11/00 , H04L

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.

26.

发明专利
未知

公开(公告)号：NO994939D0

公开(公告)日：1999-10-11

申请号：NO994939

申请日：1999-10-11

Applicant: TELIA AB

Inventor： THOLIN PER , BAHLENBERG GUNNAR , DILLNER ERIK , JOHANSSON MAGNUS , LJUNGGREN LIS-MARIE , TONVALL HARRY , WESTER PER-OLA

IPC: G06T9/00 , H04N21/236 , H04N21/434 , H04N

27.

发明专利
未知

公开(公告)号：NO990768L

公开(公告)日：1999-04-30

申请号：NO990768

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

IPC: H04J11/00 , H04B3/10 , H04L1/00 , H04L7/00 , H04L27/26 , H04L5/06

Abstract: A multi-carrier transmission system using DMT. It is known to recover a receiver sample and clock from a reserved carrier, a pilot carrier having a fixed phase. A sampling clock oscillator in a receiver is then phase locked to the pilot carrier. Multi-carrier receivers, such as DMT receivers, are normally equipped with an FFT processor. A complex number representing the pilot carrier is then available from the FFT processor output. If an FFT processor is not available, a one frequency DFT processor can be provided to produce a complex estimate of the pilot carrier. In a DMT system, frame synchronization is handled separately from sampling clock synchronization, although the two processes are intimately related and frame synchronization must be acquired before sampling clock synchronization.