Patents by Inventor Zhigang Gao

Zhigang Gao 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: 10278155
    Abstract: A plurality of first wireless devices monitor a ranging exchange of transmissions between a target wireless device and a second wireless device in order to record for each of the plurality of first wireless devices a time of reception of a first transmission that is sent from the second wireless device to the target wireless device and a time of reception of a second transmission that is sent from the target wireless device to the second wireless device. Using a timing error computed from the estimated location, a modification is made of the time of transmission of the first transmission to produce a first modified timestamp and of the time of reception of the second transmission to produce a second modified timestamp. A ranging measurement is computed of the target wireless device relative to the second wireless device using the first modified timestamp and the second modified timestamp.
    Type: Grant
    Filed: January 19, 2018
    Date of Patent: April 30, 2019
    Assignee: Cisco Technology, Inc.
    Inventors: Matthew A. Silverman, Zhigang Gao, John Matthew Swartz, Paul J. Stager
  • Publication number: 20190037496
    Abstract: Techniques are disclosed for generating 802.11 packets that simulate an 802.11ba Wake-Up Radio (WUR) packet by wireless access points (APs) that implement pre-802.11ba standards. According to one embodiment disclosed herein, a predefined bit stream including a plurality of data bits is evaluated. A data bit of the plurality is mapped to one of a plurality of subcarriers. A symbol is encoded in a data payload of a network packet based on the mapping of the data bit to the subcarrier. The symbol simulates an on-off key (OOK)-modulated symbol in a WUR sequence. The network packet is transmitted to a client device.
    Type: Application
    Filed: July 28, 2017
    Publication date: January 31, 2019
    Inventors: Zhigang GAO, Paul J. STAGER, Fred J. ANDERSON
  • Patent number: 9562449
    Abstract: An oil drain structure for an oil mist separator including a drain pipe extending from the oil mist separator into the internal combustion engine, the drain pipe having an oil discharge hole extending through a lower end portion of the drain pipe along an axial direction of the drain pipe, and a check valve including a valve body disposed below the lower end portion of the drain pipe, the valve body acting to open and close the oil discharge hole from a side of a lower surface of the lower end portion of the drain pipe, a valve head portion fitted into the drain pipe with a fine clearance as an orifice and being moveable in the axial direction of the drain pipe, and a stem portion extending through the oil discharge hole to connect the valve body and the valve head portion with each other.
    Type: Grant
    Filed: December 10, 2012
    Date of Patent: February 7, 2017
    Assignee: MAHLE FILTER SYSTEMS JAPAN CORPORATION
    Inventors: Zhigang Gao, Terumoto Mochizuki
  • Patent number: 9332557
    Abstract: In a wireless local area network, each of multiple access points, in a high density deployment, are configured to suppress co-channel interference. A first access point having a plurality of antennas beamforms a transmission to a wireless client device within a null-space or with the weakest singular eigenmodes of a wireless channel between the first access point and at least one co-channel second access point. Techniques are presented herein for situations in which any given access point has two or more co-channel access points. In addition, an access point may perform receive side suppression with respect to a transmission (made by a co-channel access point to one of its associated wireless client devices) that is received from that co-channel access point.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: May 3, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Paul J. Stager, Matthew A. Silverman, Zhigang Gao, John Blosco, Raghuram Rangarajan
  • Patent number: 9143370
    Abstract: Techniques are presented herein for distinguishing between the DC component of a real signal and DC energy of a received signal due to the radio receiver circuitry. Samples are obtained of a received signal derived from output of a receiver of a communication device. A mean of the samples is computed over a sample window comprising a predetermined number of samples. First and second thresholds are provided, the first threshold being greater than the second threshold. An absolute value of the mean is compared with respect to the first threshold and the second threshold as samples are obtained in the sample window. A selection is made between the first threshold and the second threshold for purposes of comparison with the absolute value of the mean to determine whether energy at DC is a true/real DC component of the received signal or is due to circuitry of the receiver.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: September 22, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Zhigang Gao, Raghuram Rangarajan, David Kloper
  • Publication number: 20150131593
    Abstract: In a wireless local area network, each of multiple access points, in a high density deployment, are configured to suppress co-channel interference. A first access point having a plurality of antennas beamforms a transmission to a wireless client device within a null-space or with the weakest singular eigenmodes of a wireless channel between the first access point and at least one co-channel second access point. Techniques are presented herein for situations in which any given access point has two or more co-channel access points. In addition, an access point may perform receive side suppression with respect to a transmission (made by a co-channel access point to one of its associated wireless client devices) that is received from that co-channel access point.
    Type: Application
    Filed: January 20, 2015
    Publication date: May 14, 2015
    Inventors: Paul J. Stager, Matthew A. Silverman, Zhigang Gao, John Blosco, Raghuram Rangarajan
  • Publication number: 20150085958
    Abstract: Techniques are presented herein for distinguishing between the DC component of a real signal and DC energy of a received signal due to the radio receiver circuitry. Samples are obtained of a received signal derived from output of a receiver of a communication device. A mean of the samples is computed over a sample window comprising a predetermined number of samples. First and second thresholds are provided, the first threshold being greater than the second threshold. An absolute value of the mean is compared with respect to the first threshold and the second threshold as samples are obtained in the sample window. A selection is made between the first threshold and the second threshold for purposes of comparison with the absolute value of the mean to determine whether energy at DC is a true/real DC component of the received signal or is due to circuitry of the receiver.
    Type: Application
    Filed: September 26, 2013
    Publication date: March 26, 2015
    Applicant: Cisco Technology, Inc.
    Inventors: Zhigang Gao, Raghuram Rangarajan, David Kloper
  • Patent number: 8976761
    Abstract: In a wireless local are network, each of multiple access points, in a high density deployment, are configured to suppress co-channel interference. A first access point having a plurality of antennas beamforms a transmission to a wireless client device within a null-space or with the weakest singular eigenmodes of a wireless channel between the first access point and at least one co-channel second access point. Techniques are presented herein for situations in which any given access point has two or more co-channel access points. In addition, an access point may perform receive side suppression with respect to a transmission (made by a co-channel access point to one of its associated wireless client devices) that is received from that co-channel access point.
    Type: Grant
    Filed: October 5, 2012
    Date of Patent: March 10, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Paul J. Stager, Matthew A. Silverman, Zhigang Gao, John Blosco, Raghuram Rangarajan
  • Publication number: 20140345580
    Abstract: An oil drain structure for an oil mist separator including a drain pipe extending from the oil mist separator into the internal combustion engine, the drain pipe having an oil discharge hole extending through a lower end portion of the drain pipe along an axial direction of the drain pipe, and a check valve including a valve body disposed below the lower end portion of the drain pipe, the valve body acting to open and close the oil discharge hole from a side of a lower surface of the lower end portion of the drain pipe, a valve head portion fitted into the drain pipe with a fine clearance as an orifice and being moveable in the axial direction of the drain pipe, and a stem portion extending through the oil discharge hole to connect the valve body and the valve head portion with each other.
    Type: Application
    Filed: December 10, 2012
    Publication date: November 27, 2014
    Applicant: MAHLE FILTER SYSTEMS JAPAN CORPORATIOM
    Inventors: Zhigang Gao, Terumoto Mochizuki
  • Patent number: 8861629
    Abstract: Multiple-input multiple-output (MIMO) wireless communication techniques are provided that involve mapping multiple spatial streams to corresponding modes of a wireless channel between a plurality of antennas of a first wireless communication device and a plurality of antennas of a second wireless communication device so as to allocate or distribute power unequally to the plurality of modes. In addition, techniques are provided herein to cyclically shift a mapping of spatial streams to modes of the channel.
    Type: Grant
    Filed: July 1, 2010
    Date of Patent: October 14, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Paul J. Stager, Gary L. Sugar, Matthew A. Silverman, Zhigang Gao, Chandra Vaidyanathan
  • Publication number: 20140098681
    Abstract: In a wireless local are network, each of multiple access points, in a high density deployment, are configured to suppress co-channel interference. A first access point having a plurality of antennas beamforms a transmission to a wireless client device within a null-space or with the weakest singular eigenmodes of a wireless channel between the first access point and at least one co-channel second access point. Techniques are presented herein for situations in which any given access point has two or more co-channel access points. In addition, an access point may perform receive side suppression with respect to a transmission (made by a co-channel access point to one of its associated wireless client devices) that is received from that co-channel access point.
    Type: Application
    Filed: October 5, 2012
    Publication date: April 10, 2014
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Paul J. Stager, Matthew A. Silverman, Zhigang Gao, John Blosco, Raghuram Rangarajan
  • Publication number: 20110026630
    Abstract: Multiple-input multiple-output (MIMO) wireless communication techniques are provided that involve mapping multiple spatial streams to corresponding modes of a wireless channel between a plurality of antennas of a first wireless communication device and a plurality of antennas of a second wireless communication device so as to allocate or distribute power unequally to the plurality of modes. In addition, techniques are provided herein to cyclically shift a mapping of spatial streams to modes of the channel.
    Type: Application
    Filed: July 1, 2010
    Publication date: February 3, 2011
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Paul J. Stager, Gary L. Sugar, Matthew A. Silverman, Zhigang Gao, Chandra Vaidyanathan
  • Patent number: 7391368
    Abstract: In an example embodiment, a time of arrival circuit coupled to a wireless transceiver configured to determine a time of arrival of a wireless signal. The time of arrival circuit is operative to perform a coarse-scale frequency domain correlation of the actual samples with a predetermined ideal sample. The time of arrival circuit determines a maximum coarse correlation coefficient. The time delay circuit is operative to determine a plurality of fine correlation coefficients by interpolating around the peak coarse correlation coefficient. The time of arrival circuit determines a maximum correlation coefficient from the plurality of fine correlation coefficients and a time delay associated with the maximum correlation coefficient, the time of arrival is based on the time delay associated with the maximum correlation coefficient.
    Type: Grant
    Filed: March 6, 2007
    Date of Patent: June 24, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Zhigang Gao, Paul Stager, Bretton Douglas, Brian Hart, James Amos, Yoonill Lee