Patents by Inventor Vimar Björk

Vimar Björk has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11569890
    Abstract: A transmission beam change method is disclosed for a wireless communication transmitter adapted to transmit an orthogonal frequency division multiplex (OFDM) signal using a transmission beam of a plurality of transmission beams available at the wireless communication transmitter. The method includes temporarily adapting an output power during a transmission beam change from one transmission beam to another transmission beam. In some embodiments, the transmission beam change is performed during a cyclic prefix (CP) of an OFDM symbol and the temporary adaptation is applied to only a part of the CP. Temporarily adapting the output power includes decreasing the output power to initiate the temporary adaptation and increasing the output power to terminate the temporary adaptation. In some embodiments, the temporary adaptation is performed during all transmission beam changes or only when an occurrence frequency of transmission beam changes is higher than a threshold value.
    Type: Grant
    Filed: April 4, 2018
    Date of Patent: January 31, 2023
    Assignee: Telefonaktiebolaget LM Ericsson (Publ)
    Inventors: Peter Jakobsson, Johan Thorebäck, Vimar Björk
  • Patent number: 11271299
    Abstract: In a method for calibrating at least two cross coupled antenna element groups in an antenna array, calibrating (S1) the antenna elements within each group of antenna elements. Further, in a respective calibration transceiver in each group, measuring (S2) a coupled signal within each group and a cross-coupled signal originating in another of the at least two groups. In addition, determining (S3) a respective relative phase and amplitude difference between said at least two groups based on the measured coupled signal and said cross-coupled signal, and determining (S4) the true phase and amplitude difference between the at least two groups based on the determined respective relative phase and amplitude differences. Finally, calibrating (S5) the at least two antenna groups based on the determined true phase and amplitude difference.
    Type: Grant
    Filed: July 6, 2016
    Date of Patent: March 8, 2022
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Christian Braun, Vimar Björk, Jonas Karlsson
  • Patent number: 11224022
    Abstract: A method performed by a radio network node for deciding an Automatic Gain Control (AGC) mode to be used for a received signal in a wireless communications network is provided. The radio network node estimates (301) a type of interference scenario affecting the received signal and obtains (302) information about channel quality of channels between the radio network node and connected wireless devices. Based on the estimated type of interference scenario and the obtained information about the channel quality, the radio network node dynamically decides (303) for the received signal, which AGC mode out of the following ACG modes to be used: —a slow AGC using a release timer for releasing an AGC state, —a fast AGC using a release timer for releasing an AGC state, and—a fast AGC using a trigger timer triggering an AGC state a first time interval before an interference period, and the release timer releasing the AGC state a second time interval after said interference period ends.
    Type: Grant
    Filed: September 19, 2017
    Date of Patent: January 11, 2022
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Jichang Liao, Vimar Björk, Erik Hammarberg
  • Publication number: 20210021324
    Abstract: A transmission beam change method is disclosed for a wireless communication transmitter adapted to transmit an orthogonal frequency division multiplex (OFDM) signal using a transmission beam of a plurality of transmission beams available at the wireless communication transmitter. The method includes temporarily adapting an output power during a transmission beam change from one transmission beam to another transmission beam. Typically, the transmission beam change is performed during a cyclic prefix (CP) of an OFDM symbol and the temporary adaptation is applied to only a part of the CP. Temporarily adapting the output power may include decreasing the output power to initiate the temporary adaptation and increasing the output power to terminate the temporary adaptation. For example, the temporary adaptation may be performed during all transmission beam changes or only when an occurrence frequency of transmission beam changes is higher than a threshold value.
    Type: Application
    Filed: April 4, 2018
    Publication date: January 21, 2021
    Inventors: Peter JAKOBSSON, Johan THOREBÄCK, Vimar BJÖRK
  • Patent number: 10833693
    Abstract: It is provided a provided a time-interleaved analog-to-digital converter (ADC) system comprising an input port configured to receive an analog signal, an ADC-array comprising M, M?2, ADCs arranged in parallel. Each ADC is configured to receive and to convert a portion of the analog signal into a digital signal at a sample rate fs. The ADC-system further comprises a reference ADC configured to receive and to convert the analog signal into a digital reference signal at an average sampling rate fref lower than fs. Each sampling instant of the reference ADC corresponds to a sampling instant of an ADC in the array of ADCs, and the ADC to select for each reference ADC sampling instant is randomized over time. The ADC-system also comprises a correction module configured to adjust the digital signal outputs of the ADC-array into a corrected digital output signal based on samples of the digital reference signal and the digital signals from the corresponding selected ADCs.
    Type: Grant
    Filed: May 29, 2015
    Date of Patent: November 10, 2020
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Vimar Björk, Claes Rolén
  • Publication number: 20200280936
    Abstract: A method performed by a radio network node for deciding an Automatic Gain Control (AGC) mode to be used for a received signal in a wireless communications network is provided. The radio network node estimates (301) a type of interference scenario affecting the received signal and obtains (302) information about channel quality of channels between the radio network node and connected wireless devices. Based on the estimated type of interference scenario and the obtained information about the channel quality, the radio network node dynamically decides (303) for the received signal, which AGC mode out of the following ACG modes to be used: —a slow AGC using a release timer for releasing an AGC state, —a fast AGC using a release timer for releasing an AGC state, and —a fast AGC using a trigger timer triggering an AGC state a first time interval before an interference period, and the release timer releasing the AGC state a second time interval after said interference period ends.
    Type: Application
    Filed: September 19, 2017
    Publication date: September 3, 2020
    Inventors: Jichang LIAO, Vimar BJÖRK, Erik HAMMARBERG
  • Publication number: 20200014105
    Abstract: In a method for calibrating at least two cross coupled antenna element groups in an antenna array, calibrating (S1) the antenna elements within each group of antenna elements. Further, in a respective calibration transceiver in each group, measuring (S2) a coupled signal within each group and a cross-coupled signal originating in another of the at least two groups. In addition, determining (S3) a respective relative phase and amplitude difference between said at least two groups based on the measured coupled signal and said cross-coupled signal, and determining (S4) the true phase and amplitude difference between the at least two groups based on the determined respective relative phase and amplitude differences. Finally, calibrating (S5) the at least two antenna groups based on the determined true phase and amplitude difference.
    Type: Application
    Filed: July 6, 2016
    Publication date: January 9, 2020
    Applicant: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Christian BRAUN, Vimar BJÖRK, Jonas KARLSSON
  • Patent number: 10432293
    Abstract: The present disclosure relates to a wireless communication node comprising at least one array antenna configured to receive a radio signal, said array antenna comprising a plurality of receiving antenna devices, each of said antenna devices being connected to a respective receiving circuit which is configured for processing said radio signal. Each receiving circuit comprises a demodulator, an analog-to-digital converter and a decoder, the demodulator being configured to receive an analog signal from the corresponding receiving antenna device and to output a demodulated analog signal to said analog-to-digital converter which outputs a converted digital signal to the decoder. Furthermore, the node is configured for adding a direct current, DC, offset value to said demodulated analog signal wherein the combined offset values of said node follow a predetermined distribution of values, having a variance, over the analog-to-digital converters.
    Type: Grant
    Filed: April 2, 2015
    Date of Patent: October 1, 2019
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Ulf Gustavsson, Sven Jacobsson, Giuseppe Durisi, Vimar Björk, Mikael Coldrey, Lars Sundström
  • Publication number: 20180138919
    Abstract: It is provided a provided a time-interleaved analog-to-digital converter (ADC) system comprising an input port configured to receive an analog signal, an ADC-array comprising M, M?2, ADCs arranged in parallel. Each ADC is configured to receive and to convert a portion of the analog signal into a digital signal at a sample rate fs. The ADC-system further comprises a reference ADC configured to receive and to convert the analog signal into a digital reference signal at an average sampling rate fref lower than fs. Each sampling instant of the reference ADC corresponds to a sampling instant of an ADC in the array of ADCs, and the ADC to select for each reference ADC sampling instant is randomized over time. The ADC-system also comprises a correction module configured to adjust the digital signal outputs of the ADC-array into a corrected digital output signal based on samples of the digital reference signal and the digital signals from the corresponding selected ADCs.
    Type: Application
    Filed: May 29, 2015
    Publication date: May 17, 2018
    Inventors: Vimar Björk, Claes Rolén
  • Publication number: 20180048377
    Abstract: The present disclosure relates to a wireless communication node comprising at least one array antenna configured to receive a radio signal, said array antenna comprising a plurality of receiving antenna devices, each of said antenna devices being connected to a respective receiving circuit which is configured for processing said radio signal. Each receiving circuit comprises a demodulator, an analog-to-digital converter and a decoder, the demodulator being configured to receive an analog signal from the corresponding receiving antenna device and to output a demodulated analog signal to said analog-to-digital converter which outputs a converted digital signal to the decoder. Furthermore, the node is configured for adding a direct current, DC, offset value to said demodulated analog signal wherein the combined offset values of said node follow a predetermined distribution of values, having a variance, over the analog-to-digital converters.
    Type: Application
    Filed: April 2, 2015
    Publication date: February 15, 2018
    Inventors: Ulf Gustavsson, Sven Jacobsson, Giuseppe Durisi, Vimar Björk, Mikael Coldrey, Lars Sundström
  • Patent number: 9350580
    Abstract: An aspect of the solution herein is directed to a receiver arrangement (100) including multiple RF-filters (RF1, RF2, RF3) and RF-attenuators (RF-A1, RF-A2, RF-A3), one for each of multiple frequency bands (RX1, RX2, RX3), where each RF-attenuator (RF-A1, RF-A2, RF-A3) is provided with a respective power splitter (PS1, PS2, PS3) that connects the RF-attenuator to an average power detector (Pave), which is configured to monitor an average power of each frequency band, where all frequency bands share a common antenna arrangement (110), at least one common LNA (112, 112a, 112b) and a common mixer arrangement (114) configured to mix all frequency bands into a common analog signal, and where a peak power monitor arrangement (201) is configured to monitor the peak power of the common analog signal, wherein, the receiver arrangement includes a digitizer arrangement (200) configured to control the gain of each RF-attenuator based on the monitored average power of each band from the average power detector and a detect
    Type: Grant
    Filed: September 25, 2013
    Date of Patent: May 24, 2016
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Georgios Sidiropoulos, Karl-Erik Assarsson, Vimar Björk
  • Publication number: 20150256372
    Abstract: An aspect of the solution herein is directed to a receiver arrangement (100) including multiple RF-filters (RF1, RF2, RF3) and RF-attenuators (RF-A1, RF-A2, RF-A3), one for each of multiple frequency bands (RX1, RX2, RX3), where each RF-attenuator (RF-A1, RF-A2, RF-A3) is provided with a respective power splitter (PS1, PS2, PS3) that connects the RF-attenuator to an average power detector (Pave), which is configured to monitor an average power of each frequency band, where all frequency bands share a common antenna arrangement (110), at least one common LNA (112, 112a, 112b) and a common mixer arrangement (114) configured to mix all frequency bands into a common analog signal, and where a peak power monitor arrangement (201) is configured to monitor the peak power of the common analog signal, wherein, the receiver arrangement includes a digitizer arrangement (200) configured to control the gain of each RF-attenuator based on the monitored average power of each band from the average power detector and a detect
    Type: Application
    Filed: September 25, 2013
    Publication date: September 10, 2015
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Georgios Sidiropoulos, Karl-Erik Assarsson, Vimar Björk
  • Patent number: 9113430
    Abstract: The invention discloses a base station (110, 300) for a cell (105) in a cellular communications system (100). The base station comprises a scheduler (310) for scheduling transmissions to users (115, 120) in the cell (105) and a transmitter with a power amplifier (325). The scheduler (310) is also arranged to set the output power level of the power amplifier (325) for an upcoming transmission period.
    Type: Grant
    Filed: March 3, 2009
    Date of Patent: August 18, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Jacob Österling, Vimar Björk
  • Patent number: 8849224
    Abstract: The invention provides a receiver comprising an input end, an Rx-chain with at least one regulating means and an output end. The receiver further comprises a feedback loop in the Rx-chain, the regulating means arranged for providing a higher or lower gain setting. The feedback loop comprises an AGC Multilevel threshold detector unit, AMU. The AMU comprises at least one Low Multilevel Threshold Detector, LMTD, and the LMTD comprises at least two threshold detectors, each detector having an associated low threshold level and detection interval, the length of the detection interval being shorter the lower the low threshold level is arranged to be set. The higher gain setting being arranged to be initiated through the feedback loop when the absolute level of an AGC input signal has been below at least one of the low threshold levels during the entire detection interval associated with that low threshold level.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: September 30, 2014
    Assignee: Optis Cellular Technology, LLC
    Inventor: Vimar Björk
  • Patent number: 8320865
    Abstract: The present invention relates to a method, an Automatic Gain Control control unit and a receiver for Noise change output signalling. It also relates to an Adjustment Unit, a receiver and a base band detector for adjustment of an Automatic Gain Control output signal on the basis of the Noise change output signalling. In a first step a receiver receives a communication input signal. In a second step at least one Automatic Gain Control attenuator or amplifier in the receiver attenuates the communication input signal. In a third step the receiver produces at least one AGC output signal. In a fourth step at least one AGC control unit in the receiver initiates a changed gain setting on the receiver, when the level of an AGC control unit input signal received by the unit has been below a first threshold level or above a second threshold level during a detection interval.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: November 27, 2012
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Vimar Björk
  • Patent number: 8126070
    Abstract: A method and base station for forming an OFDM signal from a baseband signal includes a partitioning unit configured to partition a block of baseband signal samples into sub-blocks. A sub-carrier mapper maps the sub-blocks onto adjacent sub-carrier blocks of an OFDM multi-carrier to form corresponding unprefixed OFDM symbols. A cyclic prefix adder adds a cyclic prefix to each mapped sub-block to form prefixed OFDM symbols. Phase compensations force the unprefixed OFDM symbol part of all subsequently up-converted prefixed OFDM symbols to start at the same phase. Up-converters up-convert the phase compensated prefixed OFDM symbols to respective radio frequency bands having center frequencies and bandwidths that preserve the OFDM multi-carrier structure. A combiner combines the up-converted phase compensated prefixed OFDM symbols into an OFDM signal.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: February 28, 2012
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Thord Hyllander, Leonard Rexberg, Jacob Österling, Vimar Björk, Tore Mikael André, Torbjörn Gunnar Widhe, Daniel Larsson
  • Publication number: 20110317606
    Abstract: The invention discloses a base station (110, 300) for a cell (105) in a cellular communications system (100). The base station comprises a scheduler (310) for scheduling transmissions to users (115, 120) in the cell (105) and a transmitter with a power amplifier (325). The scheduler (310) is also arranged to set the output power level of the power amplifier (325) for an upcoming transmission period.
    Type: Application
    Filed: March 3, 2009
    Publication date: December 29, 2011
    Applicant: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Jacob Österling, Vimar Björk
  • Patent number: 8027643
    Abstract: The present invention relates to radio base stations including a standardized interface CPRI between a Radio Equipment (RE) and a Radio Equipment Controller (REC). The present invention also relates to a method. The problem addressed is how to convey calibration information from the RE to the REC, when the capacity is occupied by radio IQ samples. The solution is to suppress the IQ samples to get capacity for the calibration information. Various embodiments of the invention focus on reducing the negative impact the suppression of IQ data may have on detecting the signals received.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: September 27, 2011
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Jacob Österling, Vimar Björk, Alireza Nejatian
  • Publication number: 20110059711
    Abstract: The present invention relates to a method, an Automatic Gain Control control unit and a receiver for Noise change output signalling. It also relates to an Adjustment Unit, a receiver and a base band detector for adjustment of an Automatic Gain Control output signal on the basis of the Noise change output signalling. In a first step a receiver receives a communication input signal. In a second step at least one Automatic Gain Control attenuator or amplifier in the receiver attenuates the communication input signal. In a third step the receiver produces at least one AGC output signal. In a fourth step at least one AGC control unit in the receiver initiates a changed gain setting on the receiver, when the level of an AGC control unit input signal received by the unit has been below a first threshold level or above a second threshold level during a detection interval.
    Type: Application
    Filed: May 15, 2008
    Publication date: March 10, 2011
    Inventor: Vimar Björk
  • Patent number: 6943627
    Abstract: The invention provides robust and non-invasive calibration of an adaptive signal conditioning system having a signal conditioning block in the signal path to a signal conversion system, and a feedback path with a number of feedback components for enabling adaptation, by means of a parameter adaptation block, of the parameters used in the signal conditioning. In order to calibrate the feedback path, a well-defined reference signal is inserted into the feedback path, and an appropriate calibration coefficient is then determined by a coefficient calibrator in response to the received reference signal. The calibration coefficient is provided to a compensator, which effectively compensates for changes in the transfer characteristics of the feedback path due to factors such as variations in ambient temperature and component aging.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: September 13, 2005
    Assignee: Telefonaktiebolaget Lm Ericsson (publ)
    Inventors: Scott Leyonhjelm, Vimar Björk, John Grass, Lennart Neovius, Paul Leather