Patents by Inventor Magnus Stig Torsten Sandell

Magnus Stig Torsten Sandell 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: 20080311859
    Abstract: Channel estimation in a MIMO communications system comprises performing a decomposition of an initial channel matrix estimate associated with a first subcarrier of a plurality thereof defined in the channel to identify eigenvectors associated with that subcarrier of the received signal, and defining a first beamforming transformation to be applied to the received signal on the basis of the eigenvectors. Then, for each of the other subcarriers, an additional decomposition is performed in order to determine a further beamforming transformation for each of said one or more other subcarriers, wherein said additional decompositions are carried out incrementally such that information determined in one of said decompositions contributes to a later executed decomposition. Further described is a method of transmitting from a multiple antenna transmitter defining a plurality of subcarriers in space, and time or frequency, comprising the same iterative process.
    Type: Application
    Filed: March 20, 2008
    Publication date: December 18, 2008
    Inventors: Vishakan Ponnampalam, Magnus Stig Torsten Sandell
  • Publication number: 20080232488
    Abstract: Detection of information on an OFDM signal involves channel estimation. Following an initial channel estimate, it is desirable to perform smoothing or filtering to achieve a more effective channel estimate. A filter is described which is operable to smooth an initial estimate for a subcarrier by reference to one or more adjacent subcarrier estimates. Extrapolation is used to impose, on a subcarrier, information dependent on one or more other subcarriers in the case that the subcarrier in question is not in use other than use by the filter.
    Type: Application
    Filed: December 13, 2007
    Publication date: September 25, 2008
    Inventors: Magnus Stig Torsten SANDELL, Andrew George LILLIE
  • Publication number: 20080181335
    Abstract: In a lattice-reduction-aided receiver based wireless communications system, outputs are determined on the basis of a received signal, the received signal being modulated onto a plurality of sub-carriers.
    Type: Application
    Filed: September 12, 2007
    Publication date: July 31, 2008
    Inventors: Vishakan Ponnampalam, Andrew George Lillie, Magnus Stig Torsten Sandell, Darren Phillip McNamara
  • Publication number: 20080123764
    Abstract: In a lattice-reduction-aided receiver based wireless communications system, soft estimates of transmitted bit values are determined from a received signal by applying lattice reduction to the channel estimate and equalising the received signal in accordance with the reduced basis channel, and determining probabilities of transmitted bits having particular values. The method includes selecting an initial candidate vector in the reduced basis and determining further candidate vectors in the reduced basis dependently of the initial candidate vector, determining a corresponding transmitted symbol vector for each candidate vector and, on the basis of the received signal determining the probability of each transmitted bit value having been transmitted and log-likelihood ratios of transmitted bits.
    Type: Application
    Filed: May 18, 2007
    Publication date: May 29, 2008
    Inventors: Darren Phillip McNamara, Andrew George LILLIE, Magnus Stig Torsten Sandell