Patents by Inventor Dieter Schulz

Dieter Schulz 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: 12563148
    Abstract: A device, system and method for cancelling echo at electronic devices are provided. The device comprises: a send path comprising a send input and output; a receive path comprising a receive input and output; an echo estimator engine that determines an estimate of echo, on the send path; a subtractor engine subtracts the estimated echo from a send signal received at the send input; a delay buffer engine; and an adder. The delay buffer engine provides, to the adder engine, a delayed-attenuated portion of a receive signal, received at the receive input, delayed by a given delay period corresponding to at least a delay of the echo between the receive path and the send input. The adder engine adds the delayed-attenuated portion to the send signal. The echo estimator engine determines the estimated echo using at least the delayed-attenuated portion of the receive signal added to the send signal.
    Type: Grant
    Filed: November 8, 2023
    Date of Patent: February 24, 2026
    Assignee: Mitel Networks Corporation
    Inventors: Dieter Schulz, Mirjana Popovic, Roger Bastin
  • Publication number: 20250150539
    Abstract: A device, system and method for cancelling echo at electronic devices are provided. The device comprises: a send path comprising a send input and output; a receive path comprising a receive input and output; an echo estimator engine that determines an estimate of echo, on the send path; a subtractor engine subtracts the estimated echo from a send signal received at the send input; a delay buffer engine; and an adder. The delay buffer engine provides, to the adder engine, a delayed-attenuated portion of a receive signal, received at the receive input, delayed by a given delay period corresponding to at least a delay of the echo between the receive path and the send input. The adder engine adds the delayed-attenuated portion to the send signal. The echo estimator engine determines the estimated echo using at least the delayed-attenuated portion of the receive signal added to the send signal.
    Type: Application
    Filed: November 8, 2023
    Publication date: May 8, 2025
    Inventors: Dieter SCHULZ, Mirjana POPOVIC, Roger BASTIN
  • Patent number: 11657829
    Abstract: A communication system with a noise cancellation (NC) assembly providing adaptive or dynamic noise cancellation. The NC assembly includes a localizer module determining, during a communication session (active speaking or during idle times), a location of the active talker. The NC assembly includes a beam generator forming a beam in the determined direction of the active talker to enhance the active talker speech. Once the NC assembly has determined the position of the active talker, the NC assembly assigns a microphone of the microphone array or generated beam in that active direction to be the “active signal” source. The NC assembly assigns a second microphone or beam to be the noise source for NC purposes, and this source may be selected to be in acoustic shadow of the first microphone used as the active signal source or may be the farthest away in its position from the active talker's position.
    Type: Grant
    Filed: April 28, 2021
    Date of Patent: May 23, 2023
    Assignee: Mitel Networks Corporation
    Inventors: Mirjana Popovic, Dieter Schulz, Roger Bastin, Andrew Wu, Logendra Naidoo
  • Publication number: 20220351742
    Abstract: A communication system with a noise cancellation (NC) assembly providing adaptive or dynamic noise cancellation. The NC assembly includes a localizer module determining, during a communication session (active speaking or during idle times), a location of the active talker. The NC assembly includes a beam generator forming a beam in the determined direction of the active talker to enhance the active talker speech. Once the NC assembly has determined the position of the active talker, the NC assembly assigns a microphone of the microphone array or generated beam in that active direction to be the “active signal” source. The NC assembly assigns a second microphone or beam to be the noise source for NC purposes, and this source may be selected to be in acoustic shadow of the first microphone used as the active signal source or may be the farthest away in its position from the active talker's position.
    Type: Application
    Filed: April 28, 2021
    Publication date: November 3, 2022
    Applicant: Mitel Networks Corporation
    Inventors: Mirjana Popovic, Dieter Schulz, Roger Bastin, Andrew Wu, Logendra Naidoo
  • Patent number: 10848201
    Abstract: A cloud based echo canceller is set forth for recreating an estimate of a lost packet or data at a server without requiring redundant data over the network or freezing operation of the echo canceller. In an exemplary embodiment, the echo cancelling function is not located in a single device, but is shared between the end-point and a cloud service, where the function of the end-point is to provide a time synchronized copy of the signal from the end-point loudspeaker and the signal received by the end-point microphone. Consequently, the high CPU intensive operations can be offloaded to a server such as a cloud server. In addition, several users can share the echo canceller, thereby reducing the cost of the overall function. According to an additional aspect, a further synchronization block is provided, in the form of a packet estimator, to compensate for packet or data loss in the send direction.
    Type: Grant
    Filed: September 26, 2019
    Date of Patent: November 24, 2020
    Assignee: Mitel Cloud Services, Inc.
    Inventor: Dieter Schulz
  • Publication number: 20200021329
    Abstract: A cloud based echo canceller is set forth for recreating an estimate of a lost packet or data at a server without requiring redundant data over the network or freezing operation of the echo canceller. In an exemplary embodiment, the echo cancelling function is not located in a single device, but is shared between the end-point and a cloud service, where the function of the end-point is to provide a time synchronized copy of the signal from the end-point loudspeaker and the signal received by the end-point microphone. Consequently, the high CPU intensive operations can be offloaded to a server such as a cloud server. In addition, several users can share the echo canceller, thereby reducing the cost of the overall function. According to an additional aspect, a further synchronization block is provided, in the form of a packet estimator, to compensate for packet or data loss in the send direction.
    Type: Application
    Filed: September 26, 2019
    Publication date: January 16, 2020
    Applicant: Mitel Cloud Services, Inc.
    Inventor: Dieter Schulz
  • Patent number: 10439673
    Abstract: A cloud based echo canceller is set forth for recreating an estimate of a lost packet or data at a server without requiring redundant data over the network or freezing operation of the echo canceller. In an exemplary embodiment, the echo cancelling function is not located in a single device, but is shared between the end-point and a cloud service, where the function of the end-point is to provide a time synchronized copy of the signal from the end-point loudspeaker and the signal received by the end-point microphone. Consequently, the high CPU intensive operations can be offloaded to a server such as a cloud server. In addition, several users can share the echo canceller, thereby reducing the cost of the overall function. According to an additional aspect, a further synchronization block is provided, in the form of a packet estimator, to compensate for packet or data loss in the send direction.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: October 8, 2019
    Assignee: Mitel Cloud Services, Inc.
    Inventor: Dieter Schulz
  • Publication number: 20190181911
    Abstract: A cloud based echo canceller is set forth for recreating an estimate of a lost packet or data at a server without requiring redundant data over the network or freezing operation of the echo canceller. In an exemplary embodiment, the echo cancelling function is not located in a single device, but is shared between the end-point and a cloud service, where the function of the end-point is to provide a time synchronized copy of the signal from the end-point loudspeaker and the signal received by the end-point microphone. Consequently, the high CPU intensive operations can be offloaded to a server such as a cloud server. In addition, several users can share the echo canceller, thereby reducing the cost of the overall function. According to an additional aspect, a further synchronization block is provided, in the form of a packet estimator, to compensate for packet or data loss in the send direction.
    Type: Application
    Filed: December 11, 2017
    Publication date: June 13, 2019
    Inventor: Dieter SCHULZ
  • Patent number: 9544702
    Abstract: Technology for dynamic characterization of a communication device is disclosed. One method comprises sending an acoustic characterization excitation signal to be output by an acoustic transducer in the communication device. A received acoustic coupling signal that is received by a microphone of the communication device in response to the output of the acoustic transducer is measured. An acoustic signal conditioning algorithm is applied to at least one of the microphone or the acoustic transducer to reduce an amplitude of the acoustic signal or the received acoustic coupling signal to a level below a selected threshold.
    Type: Grant
    Filed: July 23, 2013
    Date of Patent: January 10, 2017
    Assignee: Mitel Networks Corporation
    Inventors: Dieter Schulz, Mirjana Popovic, Chi Keung Leung, Edward P. Gancarcik
  • Publication number: 20150030168
    Abstract: Technology for dynamic characterization of a communication device is disclosed. One method comprises sending an acoustic characterization excitation signal to be output by an acoustic transducer in the communication device. A received acoustic coupling signal that is received by a microphone of the communication device in response to the output of the acoustic transducer is measured. An acoustic signal conditioning algorithm is applied to at least one of the microphone or the acoustic transducer to reduce an amplitude of the acoustic signal or the received acoustic coupling signal to a level below a selected threshold.
    Type: Application
    Filed: July 23, 2013
    Publication date: January 29, 2015
    Inventors: Dieter Schulz, Mirjana Popovic, Chi Keung Leung, Edward P. Gancarcik
  • Patent number: 8654967
    Abstract: An echo canceling system has an adaptive filter connected to an echo source, for canceling echo from an echo path. A fixed echo conditioning filter is connected in series with the adaptive filter, intermediate the echo source and the adaptive filter. The fixed echo conditioning filter cancels the constant part of the echo path using a measured impulse response of the echo path.
    Type: Grant
    Filed: December 8, 2006
    Date of Patent: February 18, 2014
    Assignee: Mitel Networks Corporation
    Inventors: Dieter Schulz, Yonghua Fang, Renee Johnston, Mirjana Popovic
  • Publication number: 20130156204
    Abstract: The present disclosure relates to a conferencing appliance. More specifically, this disclosure relates to visual feedback of audio input levels. In one illustrative embodiment, a ring-shaped indicator can be provided on a conferencing appliance. When an audio stream is received, the audio stream can be filtered by removing echoes and background noises. The appliance can determine the power level of the audio stream. The appliance can then activate the ring-shaped indicator showing the calculated power level of the audio stream. Different colors can be used showing the power level of the audio stream. Light intensity can also be used to indicate the power level of the incoming audio. The indicator can be placed on a standard telephone.
    Type: Application
    Filed: December 14, 2011
    Publication date: June 20, 2013
    Inventor: Dieter Schulz
  • Patent number: 8041055
    Abstract: A method and apparatus for automatically adjusting volume of an audio signal on a mobile device, comprising playing the audio signal at an initial volume, sampling the audio signal, estimating a transfer function based on an echo path characteristic between the played audio signal and sampled audio signal, selecting a volume policy based on the estimated transfer function, and adjusting the volume of the audio signal in accordance with the selected volume policy.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: October 18, 2011
    Assignee: Mitel Networks Corporation
    Inventors: Paul Andrew Erb, Dieter Schulz
  • Patent number: 7817797
    Abstract: An echo canceller comprising a first adaptive filter having N_long coefficients for converging to an echo path, a non-adaptive filter representing a direct echo path portion captured by the first adaptive filter and having N_short default coefficients, where N_long>N_short, for quick convergence of the echo canceller at start-up, wherein the default coefficients are replaced by the first N_short coefficients from the first adaptive filter responsive to an improvement in echo return loss enhancement (ERLE) of the first adaptive filter, a second adaptive filter having N_short default coefficients for modeling the direct echo path and providing an indication of double-talk and echo path changes, decision logic for receiving error signal outputs from the first and second adaptive filters and the non-adaptive filter and in response distinguishing between echo path changes and double-talk, and a non-linear processor for attenuating signals responsive to input from the decision logic.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: October 19, 2010
    Assignee: Mitel Networks Corporation
    Inventors: Mirjana Popovic, Dieter Schulz, Dean Swan, Andrew Wu
  • Patent number: 7792280
    Abstract: The present invention relates generally to tone detection in echo canceling systems, and more particularly to a method of monitoring oscillations of adaptive filter coefficients for narrow band tone detection in echo cancellation systems. The invention is directed at improving communication in a telephone communication network having one or more hybrid connections. A method for detecting continuous tones in an echo canceling system having an adaptive filter is provided. Continuous tones have a deleterious effect on the performance of adaptive filters. In the present invention, the adaptive filter coefficients are monitored. Oscillation of those coefficients indicates continuous tone presence.
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: September 7, 2010
    Assignee: Mitel Networks Corporation
    Inventors: Renee Johnston, Mirjana Popovic, Dieter Schulz, Jan Radecki
  • Patent number: 7747013
    Abstract: A system and method for providing early detection of encrypted signals within a secure connection for voice over Internet protocol (VoIP). The system and method includes a non-complex, in-band, and early encryption detector within the voice path. A transmitter sends out a known pattern. Based upon the received pattern, the receiver decides whether its encryption capabilities match up with those of the transmitter. If the capabilities do not match, then the receiver waits for the signalling message for the correct mode of operation. No packets are utilized until the receiver and transmitter encryption capabilities are matched.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: June 29, 2010
    Assignee: Mitel Networks Corporation
    Inventors: Dennis Deans, Lee Dilkie, Sonya G Fullarton, Radovan Prodanovic, Dieter Schulz, Dave Speirs, Jean-Yves Patry
  • Patent number: 7738653
    Abstract: A method of selecting an optimum impedance for a loop start trunk line, comprising successively applying respective ones of a plurality of impedance settings to the loop start trunk line, for each impedance setting measuring the impulse response of the trans-hybrid echo path by applying audio test signals to obtain a time-domain trans-hybrid transfer function and deriving a frequency-domain spectrum representative of trans-hybrid loss, and then calculating figure of merit of the transfer function based on the power spectrum. Once all impedance settings have been tested, the optimum impedance is selected as the impedance setting associated with the highest calculated figure of merit.
    Type: Grant
    Filed: December 7, 2006
    Date of Patent: June 15, 2010
    Assignee: Mitel Networks Corporation
    Inventors: Yonghua Fang, Mirjana Popovic, Dieter Schulz
  • Patent number: 7693276
    Abstract: A method of determining residue-echo threshold for the trans-hybrid echo path of a loop start (LS) trunk line, comprising the steps of estimating the impulse response of the trans-hybrid echo path, passing a speech-like signal through the LS trunk circuit and collecting the echo signal. The collected echo signal is compared to the convolution of the speech-like signal with the estimated impulse response. The difference between the convolution result and the collected echo signal is the residue echo, which represents the effect of nonlinearity. With different levels of excitation signal, a curve of residue echo power level against input signal level is obtained, and the distortion characteristics are derived from this curve.
    Type: Grant
    Filed: February 9, 2006
    Date of Patent: April 6, 2010
    Assignee: Mitel Networks Corporation
    Inventors: Yonghua Fang, Renee Johnston, Mirjana Popovic, Dieter Schulz
  • Patent number: 7661437
    Abstract: A food and beverage industry membrane valve structure with a membrane which separates a control compartment from a product compartment in a food or beverage handling or processing machine. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: February 16, 2010
    Assignee: APV Rosista GmbH
    Inventors: Dieter Schulz, Frank Baumbach
  • Patent number: 7630503
    Abstract: A method is provided for discriminating between the case of a single talker with an acoustic reflection and the case of two talkers, regardless of their power levels. The method is implemented in real time by performing a cross-correlation between pairs of average power signals originating from pairs of beamformers. A detection decision is then made based on the value of the cross correlation and its lag.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: December 8, 2009
    Assignee: Mitel Networks Corporation
    Inventors: Dieter Schulz, Graham Thompson, Charn Leung (David) Lo, Rafik Goubran