Patents by Inventor Yohannes Tesfai
Yohannes Tesfai 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).
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Patent number: 8111783Abstract: In one embodiment a method includes, collecting in-phase/quadrature (I/Q) data representing energy detected by a radio in a frequency band, performing a fast Fourier transform (FFT) on the I/Q data resulting in a stream of FFT blocks, identifying using the stream of FFT blocks a pulse in the frequency band, recording in a radio events record (RER) a plurality of radio events and corresponding timestamps that are indicative, respectively, of a type and time of individual state changes in the radio during the collecting step, and, for example, using at least two of the radio events to identify, in the time domain, a beginning time and end time of the pulse detected in the stream of FFT blocks.Type: GrantFiled: June 17, 2008Date of Patent: February 7, 2012Assignee: Cisco Technology, Inc.Inventors: David Kloper, Yohannes Tesfai, Chandra Vaidyanathan
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Patent number: 8086199Abstract: Systems and methods for sharing an AGC loop between a wireless data demodulator and a spectrum analysis module that operates simultaneously with the data demodulator. In one embodiment, a predetermined hold time prevents the AGC loop from changing gain too often, thereby allowing the spectrum analysis module to collect reliable data. In another embodiment, the hold time may be extended to coincide with a spectrum analysis event, such as a boundary of an FFT block. In still another embodiment, an FFT valid signal is provided such that collected FFT blocks can be designated as suspect and then subsequently processed accordingly.Type: GrantFiled: May 22, 2008Date of Patent: December 27, 2011Assignee: Cisco Technology, Inc.Inventors: David Kloper, Yohannes Tesfai, Chandra Vaidyanathan
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Publication number: 20090310661Abstract: In one embodiment a method includes, collecting in-phase/quadrature (I/Q) data representing energy detected by a radio in a frequency band, performing a fast Fourier transform (FFT) on the I/Q data resulting in a stream of FFT blocks, identifying using the stream of FFT blocks a pulse in the frequency band, recording in a radio events record (RER) a plurality of radio events and corresponding timestamps that are indicative, respectively, of a type and time of individual state changes in the radio during the collecting step, and, for example, using at least two of the radio events to identify, in the time domain, a beginning time and end time of the pulse detected in the stream of FFT blocks.Type: ApplicationFiled: June 17, 2008Publication date: December 17, 2009Applicant: Cisco Technology, Inc.Inventors: David Kloper, Yohannes Tesfai, Chandra Vaidyanathan
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Publication number: 20090296848Abstract: A communication device transmits and receives communication signals with another communication device via a plurality of antennas, a plurality of transmit tapped delay-line filters, a plurality of receive tapped delay-line filters, a combiner/analyzer with a plurality of filters for signal processing; and a plurality of computation blocks. The computation blocks determine complex weights for the tapped delay-line filters for optimizing the received signal-to-noise ratio and the range of communication of the communication device.Type: ApplicationFiled: August 10, 2009Publication date: December 3, 2009Applicant: IPR Licensing, Inc.Inventors: Yohannes Tesfai, Chandra Vaidyanathan, Gary L. Sugar
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Publication number: 20090291657Abstract: Systems and methods for sharing an AGC loop between a wireless data demodulator and a spectrum analysis module that operates simultaneously with the data demodulator. In one embodiment, a predetermined hold time prevents the AGC loop from changing gain too often, thereby allowing the spectrum analysis module to collect reliable data. In another embodiment, the hold time may be extended to coincide with a spectrum analysis event, such as a boundary of an FFT block. In still another embodiment, an FFT valid signal is provided such that collected FFT blocks can be designated as suspect and then subsequently processed accordingly.Type: ApplicationFiled: May 22, 2008Publication date: November 26, 2009Applicant: CISCO TECHNOLOGY, INC.Inventors: David Kloper, Yohannes Tesfai, Chandra Vaidyanathan
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Publication number: 20090239486Abstract: A method for improving performance of radio frequency (RF) communication of a station (STA) having an access point (AP) is disclosed. The method includes using an arbitrary set of transmit antenna weights, calculating a set of receive antenna weights, and updating the transmit antenna weights based on the receive antenna weights.Type: ApplicationFiled: June 9, 2009Publication date: September 24, 2009Applicant: IPR LICENSING, INC.Inventors: Gary L. Sugar, Chandra Vaidyanathan, Yohannes Tesfai
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Patent number: 7573945Abstract: A spatial signal processing system and method are provided to optimize the received signal-to-noise ratio (SNR) at a first radio communication device based on the transmit filter at another radio communication device. Using an estimate of the channel derived from a signal received at one device from another device, an iterative process is provided to determine complex weights for one or more tapped delay-line transmit filters at each of two communication devices that optimize the received SNR.Type: GrantFiled: December 23, 2003Date of Patent: August 11, 2009Assignee: IPR Licensing, Inc.Inventors: Yohannes Tesfai, Chandra Vaidyanathan, Gary L. Sugar
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Patent number: 7545778Abstract: A transceiver using composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The optimum transmit weight vector and receive weight vector for communication between the first and second communication devices is determined so that there is effectively joint or composite beamforming between the communication devices.Type: GrantFiled: September 20, 2005Date of Patent: June 9, 2009Assignee: IPR Licensing, Inc.Inventors: Gary L. Sugar, Chandra Vaidyanathan, Yohannes Tesfai
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Patent number: 7317419Abstract: A device and method are provided for estimating a position of a target device (e.g., a device emitting radio frequency energy) based on data pertaining to strength of an emission received from the target device. At a mobile device, emissions are received from the target device when the mobile device is at each of a plurality of positions to produce receive signal strength data representative thereof. The mobile device, also recieves signals from each of a plurality of reference devices at a corresponding known position when the mobile device is at each of the plurality of positions. The position of the target device is estimated based on receive signal strength data associated with received emissions from the target device and from the reference devices. Using the estimated position and estimated transmit power of the target device, a zone of impact of the target device is determined with respect to other wireless activity based on the estimated position and estimated transmit power of the target device.Type: GrantFiled: June 21, 2005Date of Patent: January 8, 2008Assignee: Cognio, Inc.Inventors: Gary L. Sugar, Yohannes Tesfai
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Patent number: 7236128Abstract: Techniques for reducing the complexity and improving the accuracy of receive signal strength based location systems. The system comprises a plurality of radio sensor devices placed at known positions within a space in which devices are to be located. According to one technique, the path loss is measured between all combinations of pairs of radio sensor devices based on a test signal transmitted by each radio sensor device. A path loss model is evaluated to compute modeled path loss data between all combinations of pairs of radio sensor devices. For each measured path loss, a path loss error relative to each radio sensor device is computed by taking the difference between the measured path loss and the modeled path loss. The path loss error relative to each radio sensor device at any candidate position is interpolated from the computed path loss errors.Type: GrantFiled: October 29, 2004Date of Patent: June 26, 2007Assignee: Cognio, Inc.Inventors: Gary L. Sugar, Yohannes Tesfai
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Publication number: 20060128311Abstract: A system, method and software for determining a position of a source of a radio emission. Receive signal strength data associated with reception of radio emissions is generated at each of a plurality of radio sensor devices that are at corresponding known positions in an area where the radio emissions are occurring. Using characteristics associated with reception of the radio emissions at each of the sensor devices, the receive signal strength data generated by each of the sensors is matched as corresponding to a radio emission from the same source. The characteristics used to match receive signal strength data may include spectrum analysis data and/or timing analysis data. Once the receive signal strength data is matched, position computations may be performed on the appropriate set of receive signal strength data to compute the position of the source of the radio emission.Type: ApplicationFiled: December 13, 2004Publication date: June 15, 2006Inventor: Yohannes Tesfai
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Patent number: 7050452Abstract: Interference mitigation or collision avoidance systems and procedures to allow different wireless local area network (WLAN) communication protocols to co-exist in the same frequency band, such as an unlicensed frequency band used for short-range wireless communications. The procedures ensure substantial throughput of information carried by signals of each WLAN protocol while preventing collisions between signals of different protocols.Type: GrantFiled: October 5, 2001Date of Patent: May 23, 2006Assignee: Cognio, Inc.Inventors: Gary L. Sugar, William R. Seed, Yohannes Tesfai
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Publication number: 20060013327Abstract: A transceiver using composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The optimum transmit weight vector and receive weight vector for communication between the first and second communication devices is determined so that there is effectively joint or composite beamforming between the communication devices.Type: ApplicationFiled: September 20, 2005Publication date: January 19, 2006Applicant: IPR Licensing, Inc.Inventors: Gary Sugar, Chandra Vaidyanathan, Yohannes Tesfai
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Publication number: 20050285792Abstract: Techniques for reducing the complexity and improving the accuracy of receive signal strength based location systems. The system comprises a plurality of radio sensor devices placed at known positions within a space in which devices are to be located. According to one technique, the path loss is measured between all combinations of pairs of radio sensor devices based on a test signal transmitted by each radio sensor device. A path loss model is evaluated to compute modeled path loss data between all combinations of pairs of radio sensor devices. For each measured path loss, a path loss error relative to each radio sensor device is computed by taking the difference between the measured path loss and the modeled path loss. The path loss error relative to each radio sensor device at any candidate position is interpolated from the computed path loss errors.Type: ApplicationFiled: October 29, 2004Publication date: December 29, 2005Inventors: Gary Sugar, Yohannes Tesfai
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Publication number: 20050285793Abstract: A device and method are provided for estimating a position of a target device (e.g., a device emitting radio frequency energy) based on data pertaining to strength of an emission received from the target device. At a mobile device, emissions are received from the target device when the mobile device is at each of a plurality of positions to produce receive signal strength data representative thereof. In addition, at the mobile device, signals are received from each of a plurality of reference devices at a corresponding known position (and transmitted with known transmit powers) when the mobile device is at each of said plurality of positions to produce receive signal strength data representative thereof. The position of the target device is estimated based on receive signal strength data associated with received emissions from the target device and receive signal strength data associated with received signals from the reference devices.Type: ApplicationFiled: June 21, 2005Publication date: December 29, 2005Inventors: Gary Sugar, Yohannes Tesfai
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Patent number: 6965762Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.Type: GrantFiled: October 28, 2003Date of Patent: November 15, 2005Assignee: IPR Licensing, Inc.Inventors: Gary L. Sugar, Chandra Vaidyanathan, Yohannes Tesfai
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Patent number: 6873651Abstract: A spatial signal processing system and method are provided to optimize the received signal-to-noise ratio (SNR) at a first radio communication device based on the transmit filter at another radio communication device. Using an estimate of the channel derived from a signal received at one device from another device, an iterative process is provided to determine complex weights for one or more tapped delay-line transmit filters at each of two communication devices that optimize the received SNR.Type: GrantFiled: July 18, 2002Date of Patent: March 29, 2005Assignee: Cognio, Inc.Inventors: Yohannes Tesfai, Chandra Vaidyanathan, Gary L. Sugar
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Publication number: 20040136466Abstract: A spatial signal processing system and method are provided to optimize the received signal-to-noise ratio (SNR) at a first radio communication device based on the transmit filter at another radio communication device. Using an estimate of the channel derived from a signal received at one device from another device, an iterative process is provided to determine complex weights for one or more tapped delay-line transmit filters at each of two communication devices that optimize the received SNR.Type: ApplicationFiled: December 23, 2003Publication date: July 15, 2004Applicant: Cognio, Inc.Inventors: Yohannes Tesfai, Chandra Vaidyanathan, Gary L. Sugar
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Publication number: 20040087275Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.Type: ApplicationFiled: October 28, 2003Publication date: May 6, 2004Inventors: Gary L. Sugar, Chandra Vaidyanathan, Yohannes Tesfai
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Patent number: 6687492Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.Type: GrantFiled: June 19, 2002Date of Patent: February 3, 2004Assignee: Cognio, Inc.Inventors: Gary L. Sugar, Chandra Vaidyanathan, Yohannes Tesfai