Yohannes T Tesfai, 49Stone Mountain, GA

6873651, Mar 29, 2005

Jul 18, 2002

10/064482

Yohannes Tesfai - Falls Church VA, US
Chandra Vaidyanathan - Bethesda MD, US
Gary L. Sugar - Rockville MD, US

Cognio, Inc. - Gaithersburg MD

H04B007/02

375219, 375347

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.

6965762, Nov 15, 2005

Oct 28, 2003

10/695229

Gary L. Sugar - Rockville MD, US
Chandra Vaidyanathan - Bethesda MD, US
Yohannes Tesfai - Falls Church VA, US

IPR Licensing, Inc. - Wilmington DE

H04B001/06
H04B007/00
H04B001/10
H04B015/00
H04B017/00

4552761, 455 631, 455 634, 455 69, 4551142, 455 6711, 455 6716, 455129

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.

7050452, May 23, 2006

Oct 5, 2001

09/970846

Gary L. Sugar - Rockville MD, US
William R. Seed - N. Potomac MD, US
Yohannes Tesfai - Falls Church VA, US

Cognio, Inc. - Germantown MD

H04J 3/16
H04J 3/22

370465, 370208, 370328, 370337, 370338, 370468, 370479, 455 301, 455 305, 455407, 455408, 4554261, 455433

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.

7236128, Jun 26, 2007

Oct 29, 2004

10/976509

Gary L. Sugar - Rockville MD, US
Yohannes Tesfai - Silver Spring MD, US

Cognio, Inc. - Germantown MD

G01S 3/02

342465, 342174, 342463

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. A path loss estimate between a candidate position and each radio sensor device is computed by adding the interpolated path loss error relative to that radio sensor device at the candidate position and path loss data obtained by evaluating the path loss model based on the distance between at each candidate position and the corresponding radio sensor device.

7317419, Jan 8, 2008

Jun 21, 2005

11/156463

Gary L. Sugar - Rockville MD, US
Yohannes Tesfai - Silver Spring MD, US

Cognio, Inc. - Germantown MD

G01S 3/02

342464, 342452, 4551153

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.

7545778, Jun 9, 2009

Sep 20, 2005

11/231161

Gary L. Sugar - Rockville MD, US
Chandra Vaidyanathan - Bethesda MD, US
Yohannes Tesfai - Falls Church VA, US

IPR Licensing, Inc. - Wilmington DE

H04B 7/216

370335, 370334, 370342, 375148, 342372, 4552761

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.

7573945, Aug 11, 2009

Dec 23, 2003

10/707588

Yohannes Tesfai - Falls Church VA, US
Chandra Vaidyanathan - Bethesda MD, US
Gary L. Sugar - Rockville MD, US

IPR Licensing, Inc. - Wilmington DE

H04B 7/02

375267, 375148, 375219, 375220, 375229, 455 631, 4551142, 4551143, 455501

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.

8086199, Dec 27, 2011

May 22, 2008

12/125563

David Kloper - Hudson OH, US
Yohannes Tesfai - Silver Spring MD, US
Chandra Vaidyanathan - Cleveland OH, US

Cisco Technology, Inc. - San Jose CA

H04B 17/00
H04B 1/06

4552261, 4552264, 4552321, 4552471, 455311

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.