Patents by Inventor David Hammarwall

David Hammarwall 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: 20110228758
    Abstract: The object of the present invention is to achieve a solution for handling the increased PAPR that is introduced by the FD and/or TD multi-antenna processing. This is achieved by isolating the PAPR increase to one, or a few antennas, that are matched with more powerful PAs, whereas the remaining antennas may use simpler/smaller PAs amplifying signals with smaller PAPRs.
    Type: Application
    Filed: November 10, 2009
    Publication date: September 22, 2011
    Inventors: David Hammarwall, George Jongren
  • Publication number: 20110211628
    Abstract: As a basis for precoder quantization, a channel matrix representing multi-antenna channel characteristics between a transmitter and a receiver in the mobile communications network is estimated (S1). A channel-assisted vector selection procedure (S2-S4) for iteratively selecting precoding vectors for a precoding matrix is performed. Each of a number of iterations of the novel iterative vector selection procedure generally involves evaluation (S2) of the performance of each one of a set of candidate vectors included in a given vector codebook with respect to a predetermined performance measure that is dependent on the estimated channel matrix, and selection (S3) of one of the set of candidate vectors as a respective precoding vector for the precoding matrix based on the evaluated performance. Information representative of a set of selected precoding vectors is then compiled (S5) to form a quantized representation of the precoding matrix for transmission to the transmitter side.
    Type: Application
    Filed: October 31, 2008
    Publication date: September 1, 2011
    Inventors: David Hammarwall, George Jöngren, Stefano Sorrention
  • Publication number: 20110176517
    Abstract: The present invention provides a unified, rank independent mapping between antenna ports and group/code pairs. Each antenna port is uniquely associated with one code division multiplexing (CDM) group and one orthogonal cover code (OCC). The mapping between antenna ports and group/code pairs is chosen such that, for a given antenna port, the CDM group and OCC will be the same for every transmission rank.
    Type: Application
    Filed: October 8, 2010
    Publication date: July 21, 2011
    Applicant: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Yang Hu, David Astely, David Hammarwall, George Jöngren, Xinghua Song, Jianfeng Wang
  • Publication number: 20110122968
    Abstract: According to one or more aspects, the teachings herein improve user equipment (UE) Channel State Information (CSI) feedback, by letting the precoder part of a CSI feedback report comprise factorized precoder feedback. In one or more such embodiments, the factorized precoder feedback corresponds to at least two precoder matrices, including a recommended “conversion” precoder matrix and a recommended “tuning” precoder matrix. The recommended conversion precoder matrix restricts the number of channel dimensions considered by the recommended tuning precoder matrix and, in turn, the recommended tuning precoder matrix matches the recommended precoder matrix to an effective channel that is defined in part by said recommended conversion precoder matrix.
    Type: Application
    Filed: November 22, 2010
    Publication date: May 26, 2011
    Inventors: George Jöngren, David Hammarwall
  • Publication number: 20110039497
    Abstract: In a first aspect the present invention relates to a method of compensating for propagation delay in a wireless communication system. A first base station is in communication with a first plurality of antenna units which are adapted to be in wireless communication with a first terminal. The first terminal having a terminal antenna. The first plurality of antenna units is spatially separated. The method according to the first aspect comprises the steps of determining relative propagation delay from each of the first plurality of antenna units to the terminal antenna and using the determined propagation delay to establish a delay profile to compensate for propagation delay from each of the antenna units to the first terminal and applying the delay profile to a transmission between the base station and the terminal. In a second aspect the present invention further relates to a system implementing the method according to the first aspect.
    Type: Application
    Filed: February 27, 2009
    Publication date: February 17, 2011
    Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: David Hammarwall, George Jongren
  • Publication number: 20110002233
    Abstract: Method and apparatus for enabling accurate link quality estimation of a wireless link between a sending node (400) and a receiving node (402). When the sending node receives link state reports from the receiving node, it estimates the current state of the wireless link. The sending node also determines a measurement adjusting parameter if the link state reports are deemed inaccurate in relation to the estimated link state, based on a deviation between the received link state reports and the estimated actual link state. The sending node then sends the determined measurement adjusting parameter to the receiving node, and the receiving node provides a link state report based on signal measurements adjusted by the measurement adjusting parameter. The adjusted link state report can then be used for link adaptation of the wireless link and/or for packet scheduling decisions.
    Type: Application
    Filed: June 26, 2008
    Publication date: January 6, 2011
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: David Hammarwall, George Jongren, Magnus Lundevall
  • Publication number: 20100284484
    Abstract: Data is transmitted over multiple input multiple output (MIMO) channels. Plural bit streams are modulated into multiple data symbol vectors. Each vector has a transmission rank with one vector for each MIMO channel. Transmission rank is the number of elements in a data symbol vector corresponding to the number of data streams being transmitted in parallel over each MIMO channel. The multiple data symbol vectors are preceded into multiple precoded symbol vectors using a plurality of precoder cycling sets, one set for each transmission rank including multiple different precoders. The precoders in each precoder cycling set are well-separated with respect to a plurality of distance measures. The precoding includes precoding each data symbol vector of a transmission rank with a precoder belonging to the precoder cycling set of that transmission rank. The precoded symbol vectors are then transmitted over the MIMO channels.
    Type: Application
    Filed: May 7, 2008
    Publication date: November 11, 2010
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: George Jöngren, David Hammarwall, Patrick Svedman
  • Publication number: 20100197330
    Abstract: A receiving unit or a transmitting unit of a wireless network, for facilitating noise and interference measurements on an air interface. The receiving unit includes: a network interface which obtains information relating to a time-varying layout of a silent resource element (RE) grid; an electronic memory having code in communication with the network interface which stores the information; and a processing unit in communication with the electronic memory that takes a presence of a silent RE grid into account in the reception of a control or a data channel. A method for a receiving/transmitting unit of a wireless network for facilitating noise and interference measurements on an air interface is described. Information relating to a time-varying layout of a silent resource element (RE) grid is obtained and a presence of a silent RE grid is taken into account in the reception of a control or a data channel.
    Type: Application
    Filed: February 4, 2009
    Publication date: August 5, 2010
    Inventors: David Astely, David Hammarwall, George Jongren, Per Magnus Lundevall