Patents by Inventor Vajira Samarasooriya

Vajira Samarasooriya 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: 9268800
    Abstract: A two-level database structure for use by unlicensed TVBD devices operating in TV white space comprises a central database and local databases. The central database comprises two sub-database: the central licensed database which maintains information about all licensed TV devices and the central unlicensed database which maintains information about unlicensed wireless devices operating in TV spectrum. The local database is created by each TVBD device or TVBD network when it initiates and it stores information related to all transmitters in the local area. The local databases communicate with central database to query it about licensed usage of TV spectrum and register with central database. The local databases communicate with each other to exchange information about channel usage, sensing results, transmission patterns and other information that will allow the local databases to negotiate coexistence without central coordinator.
    Type: Grant
    Filed: June 13, 2014
    Date of Patent: February 23, 2016
    Assignee: Wi-LAN Inc.
    Inventors: Jung Yee, Vajira Samarasooriya, Lingjie Li
  • Patent number: 9143774
    Abstract: A DTV pilot sensor generates DTV pilot tone detection decisions associated with monitored television band channels without knowledge or estimation of a noise level of the monitored channel.
    Type: Grant
    Filed: July 23, 2014
    Date of Patent: September 22, 2015
    Assignee: WI-LAN, INC.
    Inventors: Vajira Samarasooriya, Daniel Payer, Jung Yee
  • Publication number: 20150085801
    Abstract: A wireless local area network (WLAN) gateway uses a LTE radio frame and TV white space spectrum for data communications in a wireless local area network. In the LTE downlink frame, a predefined subset of the pilot (reference) symbol positions are used to carry information to data sinks in the WLAN.
    Type: Application
    Filed: September 25, 2014
    Publication date: March 26, 2015
    Inventors: Vajira Samarasooriya, Shiquan Wu
  • Patent number: 8976302
    Abstract: A radio frequency front end for a television band receiver and spectrum sensor includes a low noise amplifier that amplifies a received signal output of a radio frequency antenna connected to the radio frequency front end, a pin diode attenuator circuit that selectively attenuates an output of the low noise amplifier, and a buffer amplifier that amplifies an output of the pin diode attenuator.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: March 10, 2015
    Assignee: Wi-LAN, Inc.
    Inventors: Neil Birkett, Vajira Samarasooriya, Jung Yee
  • Publication number: 20150058377
    Abstract: A two-level database structure for use by unlicensed TVBD devices operating in TV white space comprises a central database and local databases. The central database comprises two sub-database: the central licensed database which maintains information about all licensed TV devices and the central unlicensed database which maintains information about unlicensed wireless devices operating in TV spectrum. The local database is created by each TVBD device or TVBD network when it initiates and it stores information related to all transmitters in the local area. The local databases communicate with central database to query it about licensed usage of TV spectrum and register with central database. The local databases communicate with each other to exchange information about channel usage, sensing results, transmission patterns and other information that will allow the local databases to negotiate coexistence without central coordinator.
    Type: Application
    Filed: June 13, 2014
    Publication date: February 26, 2015
    Inventors: Jung Yee, Vajira Samarasooriya, Lingjie Li
  • Patent number: 8949061
    Abstract: A DTV pilot tone is detected in a noisy environment by computing a power average of Fast Fourier Transform (FFT) output spectra of a received signal, finding a power peak in the averaged outputs, computing an adjustment parameter to center the power peak in a Discrete Fourier Transform bin of the averaged output spectra, applying the adjustment parameter to adjust the received signal, computing a coherent average of FFT output spectra of the adjusted signal, and, testing a power spectrum of the coherent average for the presence of the DTV pilot tone.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: February 3, 2015
    Assignee: Wi-Lan, Inc.
    Inventors: Vajira Samarasooriya, Daniel Payer, James S. Wight
  • Publication number: 20150009343
    Abstract: A wireless microphone system broadcasts a pilot tone at the designated ATSC pilot position in the TV Band channel being used by the wireless microphone system. The pilot tone is a readily detectable waveform transmitted in the ATSC pilot position. The pilot tone can be generated by any one of: a standalone pilot tone generator; a pilot tone generator incorporated into a wireless microphone receiver; or, a pilot tone generator incorporated into a wireless microphone.
    Type: Application
    Filed: July 25, 2014
    Publication date: January 8, 2015
    Inventors: Shiquan Wu, Vajira Samarasooriya
  • Publication number: 20150009339
    Abstract: A DTV pilot sensor generates DTV pilot tone detection decisions associated with monitored television band channels without knowledge or estimation of a noise level of the monitored channel.
    Type: Application
    Filed: July 23, 2014
    Publication date: January 8, 2015
    Inventors: Vajira SAMARASOORIYA, Daniel PAYER, Jung YEE
  • Publication number: 20140307565
    Abstract: A spectrum sensor detects the presence of incumbent signals in the television-band. The spectrum sensor can detect digital Advanced Television Systems Committee (ATSC) signals below a ?114 dBm signal level and wireless microphone signals below a ?110 dBm signal level with false detection rates less than 10%. A radio module receives radio-frequency signals and produces an intermediate-frequency signal reflecting signal received in a selected television channel. A baseband processor module receives the intermediate-frequency signal, digitizes it, and processes the digital data to detecting whether an incumbent signal is present in the selected channel. The processing may include using pilot detection based on power spectrum thresholding or statistic characteristic extraction to detect ATSC signals. The processing may also include using power spectrum thresholding or covariance based signal detection to detect wireless microphone signals.
    Type: Application
    Filed: January 6, 2012
    Publication date: October 16, 2014
    Applicant: WI-LAN, INC.
    Inventors: Vajira Samarasooriya, Neil Birkett, Michael Moher, Jung Yee
  • Patent number: 8848644
    Abstract: A wireless local area network (WLAN) gateway uses a LTE radio frame and TV white space spectrum for data communications in a wireless local area network. In the LTE downlink frame, a predefined subset of the pilot (reference) symbol positions are used to carry information to data sinks in the WLAN.
    Type: Grant
    Filed: August 29, 2012
    Date of Patent: September 30, 2014
    Assignee: Wi-Lan, Inc.
    Inventors: Vajira Samarasooriya, Shiquan Wu
  • Patent number: 8823806
    Abstract: A DTV pilot sensor generates DTV pilot tone detection decisions associated with monitored television band channels without knowledge or estimation of a noise level of the monitored channel.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: September 2, 2014
    Assignee: Wi-Lan, Inc.
    Inventors: Vajira Samarasooriya, Daniel Payer, Jung Yee
  • Patent number: 8792589
    Abstract: A wireless microphone system broadcasts a pilot tone at the designated ATSC pilot position in the TV Band channel being used by the wireless microphone system. The pilot tone is a readily detectable waveform transmitted in the ATSC pilot position. The pilot tone can be generated by any one of: a standalone pilot tone generator; a pilot tone generator incorporated into a wireless microphone receiver; or, a pilot tone generator incorporated into a wireless microphone.
    Type: Grant
    Filed: May 13, 2010
    Date of Patent: July 29, 2014
    Assignee: Wi-LAN Inc.
    Inventors: Shiquan Wu, Vajira Samarasooriya
  • Patent number: 8755813
    Abstract: A two-level database structure for use by unlicensed TVBD devices operating in TV white space comprises a central database and local databases. The central database comprises two sub-database: the central licensed database which maintains information about all licensed TV devices and the central unlicensed database which maintains information about unlicensed wireless devices operating in TV spectrum. The local database is created by each TVBD device or TVBD network when it initiates and it stores information related to all transmitters in the local area including location, power transmission levels, operating schedule, sensing results, backup channel information. The local databases communicate with central database to query it about licensed usage of TV spectrum and register with central database.
    Type: Grant
    Filed: July 9, 2010
    Date of Patent: June 17, 2014
    Assignee: Wi-Lan, Inc.
    Inventors: Jung Yee, Vajira Samarasooriya, Lingjie Li
  • Publication number: 20130103684
    Abstract: A two-level database structure for use by unlicensed TVBD devices operating in TV white space comprises a central database and local databases. The central database comprises two sub-database: the central licensed database which maintains information about all licensed TV devices and the central unlicensed database which maintains information about unlicensed wireless devices operating in TV spectrum. The local database is created by each TVBD device or TVBD network when it initiates and it stores information related to all transmitters in the local area including location, power transmission levels, operating schedule, sensing results, backup channel information. The local databases communicate with central database to query it about licensed usage of TV spectrum and register with central database.
    Type: Application
    Filed: July 9, 2010
    Publication date: April 25, 2013
    Applicant: WI-LAN, INC.
    Inventors: Jung Yee, Vajira Samarasooriya, Lingjie Li
  • Patent number: 8373759
    Abstract: A television band device has DTV pilot signal detection logic that generates DTV pilot signal detection decisions associated with a monitored television channel. A wireless microphone detection logic generates wireless microphone detection decisions associated with the monitored television channel. A sensing manager receives DTV pilot signal detection decisions and the wireless microphone detection decisions and analyzes at least one the respective decisions to determine whether the monitored television channel is available white space.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: February 12, 2013
    Assignee: Wi-LAN, Inc.
    Inventors: Vajira Samarasooriya, Shiquan Wu
  • Publication number: 20130018622
    Abstract: A DTV pilot tone is detected in a noisy environment by computing a power average of Fast Fourier Transform (FFT) output spectra of a received signal, finding a power peak in the averaged outputs, computing an adjustment parameter to center the power peak in a Discrete Fourier Transform bin of the averaged output spectra, applying the adjustment parameter to adjust the received signal, computing a coherent average of FFT output spectra of the adjusted signal, and, testing a power spectrum of the coherent average for the presence of the DTV pilot tone.
    Type: Application
    Filed: July 13, 2011
    Publication date: January 17, 2013
    Applicant: WI-LAN, INC.
    Inventors: Vajira Samarasooriya, Daniel Payer, James S. Wight
  • Publication number: 20120320865
    Abstract: A wireless local area network (WLAN) gateway uses a LTE radio frame and TV white space spectrum for data communications in a wireless local area network. In the LTE downlink frame, a predefined subset of the pilot (reference) symbol positions are used to carry information to data sinks in the WLAN.
    Type: Application
    Filed: August 29, 2012
    Publication date: December 20, 2012
    Applicant: WI-LAN, INC.
    Inventors: Vajira Samarasooriya, Shiquan Wu
  • Patent number: 8335204
    Abstract: A wireless local area network (WLAN) gateway may use a modified LTE radio frame and TV white space spectrum for data communications in a wireless local area network. In the modified LTE downlink frame a predefined subset of the pilot (reference) symbol subcarriers are used to carry information to data sinks in the WLAN.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: December 18, 2012
    Assignee: Wi-LAN, Inc.
    Inventors: Vajira Samarasooriya, Shiquan Wu
  • Publication number: 20120212625
    Abstract: A DTV pilot sensor generates DTV pilot tone detection decisions associated with monitored television band channels without knowledge or estimation of a noise level of the monitored channel.
    Type: Application
    Filed: February 18, 2011
    Publication date: August 23, 2012
    Applicant: WI-LAN, INC.
    Inventors: Vajira Samarasooriya, Daniel Payer, Jung Yee
  • Publication number: 20120182430
    Abstract: A radio frequency front end for a television band receiver and spectrum sensor includes a low noise amplifier that amplifies a received signal output of a radio frequency antenna connected to the radio frequency front end, a pin diode attenuator circuit that selectively attenuates an output of the low noise amplifier, and a buffer amplifier that amplifies an output of the pin diode attenuator.
    Type: Application
    Filed: March 23, 2012
    Publication date: July 19, 2012
    Applicant: WI-LAN, INC.
    Inventors: Neil Birkett, Vajira Samarasooriya, Jung Yee