Patents by Inventor Fredric Lindström

Fredric Lindström 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: 9313573
    Abstract: The present invention relates to a device, such as an audio communication device, for combining a plurality of microphone signals xn(k) into a single output signal y(k). The device comprises processing means configured to calculate control signals fn(k), and control means configured to select which microphone signal xn(k) or which combination of microphone signals xn(k) to use as output signal y(k) based on said control signals fn(k). To improve the selection, the device comprises linear prediction filters for calculating linear prediction residual signals en(k) from the plurality of microphone signals xn(k), and the processing means is configured to calculate the control signals fn(k) based on said linear prediction residual signals en(k).
    Type: Grant
    Filed: November 16, 2011
    Date of Patent: April 12, 2016
    Assignee: Limes Audio AB
    Inventors: Christian Schüldt, Fredric Lindström
  • Patent number: 8693678
    Abstract: The present invention relates to a device, such as a communication device, comprising an adaptive foreground filter configured to calculate a first echo estimation signal based on a first input signal, and an adaptive background filter being more rapidly adapting than the foreground filter and configured to calculate a second echo estimation signal based on said first input signal. Embodiments of the device further comprise damping control means for controlling damping of an echo-cancelled output signal. The device in various embodiments includes that the damping control means is configured to calculate a maximum echo estimation signal using both the first and the second echo estimation signals, and control the damping of the echo-cancelled output signal based on said maximum echo estimation signal and/or a signal derived from said maximum echo estimation signal.
    Type: Grant
    Filed: June 17, 2010
    Date of Patent: April 8, 2014
    Assignee: Limes Audio AB
    Inventors: Fredric Lindström, Christian Schüldt, Ingvar Claesson
  • Publication number: 20130322655
    Abstract: The present invention relates to a device, such as an audio communication device, for combining a plurality of microphone signals xn(k) into a single output signal y(k). The device comprises processing means configured to calculate control signals fn(k), and control means configured to select which microphone signal xn(k) or which combination of microphone signals xn(k) to use as output signal y(k) based on said control signals fn(k). To improve the selection, the device comprises linear prediction filters for calculating linear prediction residual signals en(k) from the plurality of microphone signals xn(k), and the processing means is configured to calculate the control signals fn(k) based on said linear prediction residual signals en(k).
    Type: Application
    Filed: November 16, 2011
    Publication date: December 5, 2013
    Applicant: Limes Audio AB
    Inventors: Christian Schüldt, Fredric Lindström