Patents by Inventor Mithat C. Dogan

Mithat C. Dogan 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: 10447725
    Abstract: This disclosure relates to techniques for performing secure ranging wireless communication. A first wireless device may receive a ranging packet from a second wireless device in a wireless manner. The ranging packet may include a first random sequence portion and a second random sequence portion. The first wireless device may perform one or more channel and noise estimations for the ranging packet. The first wireless device may perform one or more security checks for the ranging packet based on any or all of the first random sequence portion, the second random sequence portion, or the channel and noise estimation(s).
    Type: Grant
    Filed: August 1, 2017
    Date of Patent: October 15, 2019
    Assignee: Apple Inc.
    Inventors: Mingguang Xu, Mithat C. Dogan, Yakun Sun, Rohit U. Nabar
  • Publication number: 20190238368
    Abstract: The embodiments herein use a factorization based technique for determining filter coefficients for a subset of the subcarriers in a wireless frequency band. Once the filter coefficients for the subset of the subcarriers are calculated, the network device uses these filter coefficients to identify the filter coefficients in a neighboring subcarrier. To do so, the network device uses pseudo-inverse iteration to convert the already calculated filter coefficients into filter coefficients for a neighboring subcarrier. The network device can repeat this process for the next set of neighboring subcarriers until all the filter coefficients have been calculated.
    Type: Application
    Filed: April 8, 2019
    Publication date: August 1, 2019
    Inventors: Mithat C. DOGAN, Brian D. HART, Jiunming HUANG, Matthew A. SILVERMAN
  • Patent number: 10367550
    Abstract: The present disclosure discloses that a device uses precoding to transmit independent data streams to existing users and additional independent data streams to one or more new users simultaneously. During a first transmission of a first one or more data streams that are precoded using a first precoding matrix, the device determines to transmit a second one or more data streams in a second transmission. Before the first transmission is complete, the device calculates a combined precoding matrix for precoding the first one or more data streams and the second one or more data streams. The device transmits the first one or more data streams in the first transmission and the second one or more data streams in the second transmission simultaneously using the combined precoding matrix.
    Type: Grant
    Filed: April 3, 2017
    Date of Patent: July 30, 2019
    Assignee: Cisco Technology, Inc.
    Inventors: David S. Kloper, Mithat C. Dogan, Matthew A. Silverman, Brian D. Hart, Jiunming Huang
  • Patent number: 10326538
    Abstract: Embodiments herein describe calibrating a plurality of radio heads having a plurality of wireless antennas. In one embodiment, the plurality of radio heads communicate a calibration signal in a round robin fashion such that each of the radio heads communicates a respective calibration signal to the remaining radio heads. The received calibration signals are then used to calibrate the radio heads. In one embodiment, a controller coupled with the plurality of radio heads calibrates the radio heads. The calibrated radio heads then communicate to one or more client devices.
    Type: Grant
    Filed: April 5, 2017
    Date of Patent: June 18, 2019
    Assignee: Cisco Technology, Inc.
    Inventors: Mithat C. Dogan, Jiunming Huang, Brian D. Hart, Matthew A. Silverman
  • Patent number: 10256997
    Abstract: The embodiments herein use a factorization based technique for determining filter coefficients for a subset of the subcarriers in a wireless frequency band. Once the filter coefficients for the subset of the subcarriers are calculated, the network device uses these filter coefficients to identify the filter coefficients in a neighboring subcarrier. To do so, the network device uses pseudo-inverse iteration to convert the already calculated filter coefficients into filter coefficients for a neighboring subcarrier. The network device can repeat this process for the next set of neighboring subcarriers until all the filter coefficients have been calculated.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: April 9, 2019
    Assignee: Cisco Technology, Inc.
    Inventors: Mithat C. Dogan, Brian D. Hart, Jiunming Huang, Matthew Silverman
  • Publication number: 20190037549
    Abstract: Communicating wireless devices collaborate and utilize waveforms to enable secure channel estimation. To protect against a repetitive replay attack, some embodiments include Single Carrier Physical Layer (SC-PHY) waveforms and/or interpolated OFDM waveforms that do not include a repeatable or predictable structure. The waveforms are transmitted in ranging packet structures that are compatible with legacy 802.11 technologies that do not utilize secure channel estimation. The ranging packets are received in combination with the information previously exchanged to enable the receiving wireless system to securely determine a channel estimate (e.g., determine a channel estimate without an interloper transmission that is not an authentic first arrival path in a multi-path channel between the wireless systems). Thus, one or both of the wireless systems can estimate the distance between them (or range). Devices utilizing legacy 802.
    Type: Application
    Filed: March 27, 2018
    Publication date: January 31, 2019
    Applicant: Apple Inc.
    Inventors: Mingguang Xu, Su Khiong Yong, Mithat C. Dogan, Rohit U. Nabar, Qi Wang, Kyle C. Brogle, Andrew J. Ringer
  • Publication number: 20180294898
    Abstract: Embodiments herein describe calibrating a plurality of radio heads having a plurality of wireless antennas. In one embodiment, the plurality of radio heads communicate a calibration signal in a round robin fashion such that each of the radio heads communicates a respective calibration signal to the remaining radio heads. The received calibration signals are then used to calibrate the radio heads. In one embodiment, a controller coupled with the plurality of radio heads calibrates the radio heads. The calibrated radio heads then communicate to one or more client devices.
    Type: Application
    Filed: April 5, 2017
    Publication date: October 11, 2018
    Inventors: Mithat C. DOGAN, Jiunming HUANG, Brian D. HART, Matthew A. SILVERMAN
  • Publication number: 20180287674
    Abstract: The present disclosure discloses that a device uses precoding to transmit independent data streams to existing users and additional independent data streams to one or more new users simultaneously. During a first transmission of a first one or more data streams that are precoded using a first precoding matrix, the device determines to transmit a second one or more data streams in a second transmission. Before the first transmission is complete, the device calculates a combined precoding matrix for precoding the first one or more data streams and the second one or more data streams. The device transmits the first one or more data streams in the first transmission and the second one or more data streams in the second transmission simultaneously using the combined precoding matrix.
    Type: Application
    Filed: April 3, 2017
    Publication date: October 4, 2018
    Inventors: David S. KLOPER, Mithat C. DOGAN, Matthew A. SILVERMAN, Brian D. HART, Jiunming HUANG
  • Publication number: 20180176044
    Abstract: The embodiments herein use a factorization based technique for determining filter coefficients for a subset of the subcarriers in a wireless frequency band. Once the filter coefficients for the subset of the subcarriers are calculated, the network device uses these filter coefficients to identify the filter coefficients in a neighboring subcarrier. To do so, the network device uses pseudo-inverse iteration to convert the already calculated filter coefficients into filter coefficients for a neighboring subcarrier. The network device can repeat this process for the next set of neighboring subcarriers until all the filter coefficients have been calculated.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 21, 2018
    Inventors: Mithat C. Dogan, Brian D. Hart, Jiunming Huang, Matthew Silverman
  • Patent number: 9991972
    Abstract: Embodiments herein describe calibrating a plurality of radio heads having a plurality of wireless antennas. In one embodiment, the plurality of radio heads communicate a calibration signal in a round robin fashion such that each of the radio heads communicates a respective calibration signal to the remaining radio heads. In one embodiment, at least one of the radio heads is isolated from the remaining radio heads. The received calibration signals are then used to calibrate the radio heads. In one embodiment, a controller coupled with the plurality of radio heads calibrates the radio heads. The calibrated radio heads then communicate to one or more client devices.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: June 5, 2018
    Assignee: Cisco Technology, Inc.
    Inventors: Mithat C. Dogan, Matthew A. Silverman, Paul J. Stager, Brian D. Hart, Jiunming Huang
  • Patent number: 9942020
    Abstract: Embodiments herein describe recovering data packets received by a plurality of wireless antennas of a radio head. In one embodiment, the signals received by the radio head are filtered using a single filter to recover at least one data packet. In another embodiment, the signals received by the radio head are filtered using a plurality of filters to recover at least one data packet. In one embodiment, a controller coupled with the radio head filters the received signals and recovers the at least one data packet.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: April 10, 2018
    Assignee: Cisco Technology, Inc.
    Inventors: Mithat C. Dogan, Brian D. Hart, Matthew A. Silverman
  • Patent number: 8325847
    Abstract: The present invention efficiently stores a training sequence in a communications system, where the training sequence exhibits certain desirable characteristics when used by a peak to average power constrained modulation format.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: December 4, 2012
    Assignee: Intel Corporation
    Inventors: Mithat C. Dogan, Mitchell D. Trott
  • Patent number: 7720161
    Abstract: Embodiments of the present invention can be used to generate a family of core training sequences having desired cross-correlation and out-of-phase auto-correlation properties for a communications system. The family can be generated by selecting seed sequences, so that the worst-case cross-correlation of the seed sequences is below a first initial threshold and the worst-case out-of-phase auto-correlation of the seed sequences is below a second initial threshold. Then, sequence families can be generated by inserting additional symbols into a corresponding seed sequence. Then, reduced sequence families can be generated by eliminating those sequences from the sequence families that have a worst-case out-of-phase auto-correlation above a third threshold. A sequence is selected from each reduced sequence family, so that the worst-case cross-correlation of the selected sequences is below a fourth threshold.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: May 18, 2010
    Assignee: Intel Corporation
    Inventors: Mithat C. Dogan, Mitchell D. Trott
  • Publication number: 20100086078
    Abstract: The present invention efficiently stores a training sequence in a communications system, where the training sequence exhibits certain desirable characteristics when used by a peak to average power constrained modulation format.
    Type: Application
    Filed: October 3, 2008
    Publication date: April 8, 2010
    Inventors: MITHAT C. DOGAN, Mitchell D. Trott
  • Patent number: 7512109
    Abstract: In one embodiment, the present invention includes a slot in a repeating time division frame with a first training sequence, an information sequence after the first training sequence, and a second training sequence after the information sequence. In some embodiments either the first or the second training sequences indicates a type for the information sequence, such as a random access channel message and a traffic channel message, a configuration message, a channel assignment message, or a data traffic message.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: March 31, 2009
    Assignee: Intel Corporation
    Inventors: Mitchell D. Trott, Mithat C. Dogan, Paul Petrus, Sundar G. Sankaran
  • Patent number: 7433418
    Abstract: Some embodiments store a training sequence in a communications system. The stored training sequence exhibits certain desirable characteristics when used by a peak to average power constrained modulation format. In one embodiment, a set of original ordered sequences is selected to have at least one desired property. A set of extended sequences is created from the original sequences by beginning with an element of an original sequence and cyclically appending elements of the original sequence in order to obtain a desired extended sequence length. Each extended sequence is modified using a corresponding modifying sequence, such that a training sequence can be generated from any one of the modified extended sequences. Each modifying sequence is selected so that the generated training sequence when modulated by a selected modulation format has the at least one desired property of the corresponding original ordered sequence.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: October 7, 2008
    Assignee: ArrayComm, LLC
    Inventors: Mithat C. Dogan, Mitchell D. Trott
  • Patent number: 7430606
    Abstract: The certificate revocation lists at access points of a wireless access network can be reduced. In one embodiment, an Internet Service Provider (“ISP”) connected to the wireless access network can receive a subscription request from a user terminal capable of accessing the ISP using the wireless access network. When the ISP assigns a subscription identifier to the user terminal, it also provides a service certificate signed by a certificate authority including the subscription identifier. In addition, the ISP also provides the user terminal one or more session certificates to be used to access the wireless access network, where the session certificates having a shorter validity period than the service certificate.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: September 30, 2008
    Assignee: ArrayComm, LLC
    Inventors: Branislav Meandzija, Mithat C. Dogan, Marc Goldburg
  • Patent number: 7339981
    Abstract: Embodiments of the present invention can be used to select a training sequence used by a base station and a user terminal for communications. In one embodiment, selecting the training sequence to use includes first selecting a training sequence from a set of training sequences. Then, a shift indicator is received, the shift indicator indicating a number of symbols the training sequence is to be shifted. A shifted training sequence is generated by shifting the selected training sequence by the number indicated by the received shift indicator, and the shifted training sequence is used for communication with a first transceiver on a communications channel. In another embodiment, a shift indicator indicating a number of symbols a training sequence is to be shifted is first selected, and then used to generate a shifted training sequence by shifting the training sequence by the number of symbols indicated by the selected shift indicator.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: March 4, 2008
    Assignee: ArrayComm, LLC.
    Inventor: Mithat C. Dogan
  • Patent number: 7027837
    Abstract: A system and method for communicating information between two locations via a wireless microwave link is provided. The system includes at least two antennas, each to transmit information as a narrow beam signal to be directed toward a focal point at a remote location. The antennas include at least one antenna to transmit a narrow beam signal toward a redirection point different from the focal point. A redirection device is located at the redirection point to receive the narrow beam signal from the at least one antenna element and to redirect the received narrow beam signal toward the receiver. The redirection point is located such that the narrow beam signals from the at least two antenna elements converge and overlap to form proximate to the receiver, an interference pattern that includes peaks and nulls having a peak-to-peak spacing narrower than the width of each received narrow beam signal.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: April 11, 2006
    Assignee: ArrayComm LLC.
    Inventors: Christopher R. Uhlik, Mithat C. Dogan
  • Patent number: 7016429
    Abstract: A method and apparatus are provided that generate, transmit, or receive a training sequence in a communications system, where the training sequence exhibits certain desirable characteristics when used by a peak to average power constrained modulation formal. In one embodiment, the invention includes selecting an original training sequence from a set of possible original training sequences having at least one desired property, forming a modified training sequence by modifying the original training sequence based on a corresponding modifying sequence, such that the modified training sequence exhibits the desired property of the original training sequence when used in a peak to average power constrained modulation format that would otherwise impair the desired property of the original training sequence.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: March 21, 2006
    Assignee: ArrayComm, LLC
    Inventors: Mithat C. Dogan, Mitchell D. Trott