Patents by Inventor Fredrik Nordstrom

Fredrik Nordstrom 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).

  • Publication number: 20150117327
    Abstract: Network-side and device-side methods and apparatuses improve transmit link adaptation for devices operating in a cellular network that have interference-canceling receivers. Own-cell link adaptation towards a device in a current transmission interval exploits a determined mapping between the interfering-signal cancelation efficiency of the device versus the interfering-signal transport format, in combination with actual knowledge of the transport format that will be used to make an interfering neighbor-cell transmission in the current transmission interval. For example, a serving radio node uses the known transport format of the interfering transmission, to accurately determine the expected cancellation efficiency for the device with respect to the interfering transmission, and uses the expected cancellation efficiency to obtain a more accurate estimate of the own-cell channel quality expected for the device in the current transmission interval.
    Type: Application
    Filed: March 4, 2014
    Publication date: April 30, 2015
    Inventors: Fredrik Nordström, Andres Reial
  • Patent number: 9014169
    Abstract: In a heterogeneous network, low power cells are detected by correlating a first and second signal originating from an unknown cell, such as synchronization signals, e.g., SSS received in a first and second time period (e.g., subframes 0 and 5 of a frame with corresponding sets of possible SSS signals. The cell identities for the candidate cells can be used to determine corresponding reference symbol sequences for the candidate cells. The final determination of the cell identity is then made by correlating a third signal originating from the unknown cell, such as a reference signal received in a third time period (e.g., an almost blank subframe or a broadcast subframe) with the set of reference signals for the candidate cells. The correct cell identity is determined to be the cell identity yielding the greatest correlation with its corresponding reference signal.
    Type: Grant
    Filed: June 15, 2011
    Date of Patent: April 21, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Bengt Lindoff, Fredrik Nordström
  • Publication number: 20150094108
    Abstract: In a method and a mobile communications receiver for processing signals from a first cell and a second cell a timing of the signal from the first cell and the second cell is obtained. A timing difference (?) between the timings of signals from the first and the second cell is determined and based on that a timing (?) for a window for discrete Fourier transform, DFT, processing is adjusted. DFT processing of the signals using the timing (?) of the DFT window is then performed.
    Type: Application
    Filed: December 6, 2014
    Publication date: April 2, 2015
    Inventors: Fredrik Nordstrom, Bengt Lindoff
  • Patent number: 8953698
    Abstract: A transmitted OFDM signal is detected in a receiver of a wireless communication system. The receiver has at least two receiver branches, each comprising an antenna, a front end receiver, a Discrete Fourier Transform unit, and a channel estimator. The receiver further comprises a detector for detecting received data symbols. The method comprises the steps of determining a system bandwidth associated with the transmitted signal; comparing the determined system bandwidth with a predetermined value; determining, if the system bandwidth is lower than the predetermined value, channel estimates separately for each branch, and detecting received data symbols from the received signals and corresponding channel estimates; and calculating, if the system bandwidth is higher than the predetermined value, a weighted sum of signals from each branch, determining a combined channel estimate, and detecting received data symbols from the weighted sum and the combined channel estimate.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: February 10, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Bengt Lindoff, Bo Lincoln, Fredrik Nordström
  • Patent number: 8934842
    Abstract: In a method and a mobile communications receiver for processing signals from a first cell and a second cell a timing of the signal from the first cell and the second cell is obtained. A timing difference (?) between the timings of signals from the first and the second cell is determined and based on that a timing (?) for a window for discrete Fourier transform, DFT, processing is adjusted. DFT processing of the signals using the timing (?) of the DFT window is then performed.
    Type: Grant
    Filed: May 9, 2014
    Date of Patent: January 13, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Fredrik Nordstrom, Bengt Lindoff
  • Patent number: 8903349
    Abstract: A receiver is operated in a first power mode, for example a high power mode, during a first portion of a particular connection state (for example, a RRC_CONNECTED state in LTE when the UE receiver is on) of a communication protocol being used by the telecommunications network, and a second power mode during a second portion of the particular connection state, for example a low power mode.
    Type: Grant
    Filed: November 24, 2011
    Date of Patent: December 2, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Bengt Lindoff, Fredrik Nordström
  • Patent number: 8861572
    Abstract: A method of delay spread compensation, suitable for use in a communication device a having plurality of receiver antennas, is disclosed. The method comprises receiving a plurality of signals, each via a respective antenna, wherein each signal comprises a signal component corresponding to a transmitted signal, and wherein each received signal experiences a respective channel impulse response having a corresponding delay spread; determining estimates of each of the channel impulse responses; calculating post-coding characteristics based on the estimates of the channel impulse responses; and post-coding the plurality of received signals using the post-coding characteristics to produce at least a first delay spread compensated signal. Corresponding computer program product, processing arrangement and communication device are also disclosed.
    Type: Grant
    Filed: January 20, 2010
    Date of Patent: October 14, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Bengt Lindoff, Fredrik Nordström, Bo Lincoln, Anders Rosenqvist
  • Patent number: 8837642
    Abstract: The invention relates to a method performed in a user equipment for estimating channel quality. The user equipment is adapted to operate in a multiple input multiple output (MIMO) mode in a communication system comprising a base station node supporting MIMO and serving the user equipment. The method comprises: receiving, from the base station node, a reference signal; performing joint demodulation of the reference signal, thereby obtaining soft values; and generating the channel quality using the soft values. The invention also relates to a user equipment, computer programs and computer program products.
    Type: Grant
    Filed: March 21, 2013
    Date of Patent: September 16, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Niklas Andgart, Matthias Kamuf, Fredrik Nordström
  • Publication number: 20140248847
    Abstract: In a method and a mobile communications receiver for processing signals from a first cell and a second cell a timing of the signal from the first cell and the second cell is obtained. A timing difference (?) between the timings of signals from the first and the second cell is determined and based on that a timing (?) for a window for discrete Fourier transform, DFT, processing is adjusted. DFT processing of the signals using the timing (?) of the DFT window is then performed.
    Type: Application
    Filed: May 9, 2014
    Publication date: September 4, 2014
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (publ)
    Inventors: Fredrik Nordstrom, Bengt Lindoff
  • Publication number: 20140200020
    Abstract: A method of a transceiver arranged to operate in a cellular communication system comprising cells is disclosed. The method comprises receiving a transmission from a first cell; determining an interfering signal and its occupation in time and/or frequency; determining reduced values in the received signal corresponding to the occupation in time and/or frequency of the interfering signal; and measuring a quotient between desired signal and non-desired signal of reference symbols of the received signal. A channel quality index, CQI, is formed taking into account reduction of values performed at the reducing, and the CQI is reported to the communication system. A transceiver and computer program for the same are also disclosed.
    Type: Application
    Filed: July 5, 2012
    Publication date: July 17, 2014
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Bengt Lindoff, Fredrik Nordström
  • Patent number: 8768258
    Abstract: In a method and a mobile communications receiver for processing signals from a first cell and a second cell a timing of the signal from the first cell and the second cell is obtained. A timing difference (?) between the timings of signals from the first and the second cell is determined and based on that a timing (?) for a window for discrete Fourier transform, DFT, processing is adjusted. DFT processing of the signals using the timing (?) of the DFT window is then performed.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: July 1, 2014
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Fredrik Nordström, Bengt Lindoff
  • Patent number: 8744020
    Abstract: A frequency offset of a received signal comprising a number of subsequently received data symbols is estimated. A first estimate is determined from a calculated change in phase of the received signal between two received symbols having a first time distance between them. At least one further estimate is determined from a calculated change in phase of the received signal between two received symbols having a different time distance. A frequency periodicity is determined for each estimate from the distance between the two received symbols from which the estimate was determined. A set of integer values is determined for each estimate so that frequency values calculated for each estimate as the frequency periodicity multiplied by the integer value added to the estimate are at least approximately equal to each other, and a corrected estimate of the frequency offset is determined from the integer values.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: June 3, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Niklas Andgart, Fredrik Nordström
  • Patent number: 8687745
    Abstract: According to the teachings presented herein, a method and apparatus provide a reduced search space for blindly decoding a message included in a signal received at a communication receiver, where the message has an unknown format. Improving blind detection efficiency in this manner offers numerous advantages, including but not limited to lower power consumption through reduced processing overhead, and lower power consumption through expanded sleep opportunities. As a non-limiting example, the communication receiver comprises a mobile station configured for operation according to Long Term Evolution (LTE) standards, as promulgated by the 3GPP for E-UTRA systems, where the mobile station is configured to reduce a search space of DCI message decoding by determining message format likelihoods and blindly decoding a received DCI message based on the message format likelihoods.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: April 1, 2014
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Bengt Lindoff, Matthias Kamuf, Fredrik Nordström
  • Patent number: 8644403
    Abstract: An Orthogonal Frequency Division Multiplexing (OFDM) symbol for transmission from a non-reference transceiver to a user equipment (UE) in a mobile communication system is generated by ascertaining a general timing for transmission of OFDM symbols, in which the general timing is associated with a reference transceiver. A UE timing relative to the general timing is ascertained. An initial resource element (RE) value is adjusted by a pre-compensating amount to obtain a pre-compensated RE value, in which the pre-compensating amount is based on the UE timing relative to the general timing. The pre-compensated resource element value is supplied as one of a plurality of values to be transmitted. An IFFT is performed on the plurality of values to be transmitted to obtain pre-compensated initial signal information. A cyclic prefix is appended to the pre-compensated initial signal information to form an OFDM symbol for transmission from the non-reference transceiver to the UE.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: February 4, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Bengt Lindoff, Fredrik Nordstrom, Leif Wilhelmsson
  • Publication number: 20130336280
    Abstract: In a system using spatial precoding, in the event that reliable channel state information is unavailable, a transmitting node uses an extended transmission mode, in which the precoders applied to data within each of several groups of time-frequency resources vary according to frequency. The extended transmission mode creates a frequency-selective variation in precoders, which may appear to be random, while using DMRS-based transmission. This variation is achieved by applying different precoders to the resource elements carrying data, using a pattern of precoder variation that is known to the receiving device. The precoding applied to DMRS within a given group of time-frequency resources is held constant—thus, the varying precoders within a given group of time-frequency resources are only applied to data elements, not to the DMRS resource elements.
    Type: Application
    Filed: June 19, 2012
    Publication date: December 19, 2013
    Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Fredrik Nordström, Bengt Lindoff
  • Publication number: 20130336135
    Abstract: In a system using spatial precoding, in the event that reliable channel state information is unavailable, a transmitting node artificially creates a randomization of the precoders applied to the transmitted signal. Different precoding vectors are applied to both transmitted data and demodulation reference signals for each of several groups of time-frequency resources, where the precoding vectors vary randomly or pseudo-randomly from each group of time-frequency resources to the next frequency-adjacent group or groups, or to the next time-adjacent group or groups, or both. In an LTE system in particular, this randomization of precoders can be applied at the resource-block level or, at the level of the Precoding Resource block Group (PRG), for example. Thus, the precoders applied to the transmitted signal vary from one PRG to the next, in a random or pseudo-random fashion.
    Type: Application
    Filed: June 19, 2012
    Publication date: December 19, 2013
    Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Bengt Lindoff, Fredrik Nordström
  • Patent number: 8594210
    Abstract: Methods for positioning an FFT-window in an OFDM-receiver are disclosed as well as electronic apparatuses and computer program products for performing the methods. The method comprises determining a position of the FFT-window in relation to one or more OFDM-symbols of a received OFDM-signal, using the position of the FFT-window to obtain a first OFDM-symbol from the received OFDM-signal, and applying an FFT to the first OFDM-symbol to produce an FFT-output signal. The method also comprises determining a frequency dependent phase rotation component of the FFT-output signal, and removing the determined frequency dependent phase rotation component from the FFT-output signal to obtain a compensated FFT-output signal. A delay spread estimate is calculated based on at least one of the FFT-output signal and the compensated FFT-output signal, and the position of the FFT-window is adjusted based on at least the determined frequency dependent phase rotation component and the calculated delay spread estimate.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: November 26, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Leif Wilhelmsson, Lars Björkman, Fredrik Nordström
  • Publication number: 20130279634
    Abstract: The invention relates to a method performed in a user equipment for estimating channel quality. The user equipment is adapted to operate in a multiple input multiple output (MIMO) mode in a communication system comprising a base station node supporting MIMO and serving the user equipment. The method comprises: receiving, from the base station node, a reference signal; performing joint demodulation of the reference signal, thereby obtaining soft values; and generating the channel quality using the soft values. The invention also relates to a user equipment, computer programs and computer program products.
    Type: Application
    Filed: March 21, 2013
    Publication date: October 24, 2013
    Inventors: Niklas Andgart, Matthias Kamuf, Fredrik Nordstrom
  • Publication number: 20130237171
    Abstract: A receiver is operated in a first power mode, for example a high power mode, during a first portion of a particular connection state (for example, a RRC_CONNECTED state in LTE when the UE receiver is on) of a communication protocol being used by the telecommunications network, and a second power mode during a second portion of the particular connection state, for example a low power mode.
    Type: Application
    Filed: November 24, 2011
    Publication date: September 12, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Bengt Lindoff, Fredrik Nordström
  • Patent number: 8520777
    Abstract: A receiver operates in a mobile communication system that comprises first node and second nodes, the first and second nodes transmitting common control signals and dedicated data signals, respectively. The receiver determines a first timing rotation and/or a first frequency rotation of the common control signals and a second timing rotation and/or a second frequency rotation of the dedicated data signals. The receiver determines a first and/or second difference, wherein the first difference is a difference between the first timing rotation of the common control signals and the second timing rotation of the dedicated data signals and the second difference is a difference between the first frequency rotation of the common control signals and the second frequency rotation of the dedicated data signals. An adapted timing of dedicated data signals is produced based on the first and/or second differences, and the adapted timing is used to receive dedicated data signals.
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: August 27, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Bengt Lindoff, Fredrik Nordström