Patents by Inventor Linbo Li

Linbo Li 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: 7873126
    Abstract: The disclosure is directed to a mobile communication device that includes automatic gain control (AGC) circuitry. Every n samples of the broadcast signals, an energy estimate of the AGC output signal is used to calculate and update a gain control value. Instead of using all n samples occurring subsequent to a previous gain control value update, only a subset of those n samples are used. In particular the first half of the n samples may be discarded in the energy estimate calculation while only the second half of the n samples may be used.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: January 18, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Vinay Murthy, Linbo Li, Raghuraman Krishnamoorthi
  • Patent number: 7873340
    Abstract: Systems and methods are provided for tracking and compensating for analog gain mismatches or changes in a receiver. In an embodiment, a method is provided to track analog gain step magnitudes during operation of a device. The method includes employing an error signal between an automatic gain control (AGC) output and a reference level as input to a gain step magnitude tracking component. This also includes determining at least one compensation value from the AGC output to update a nominal gain step magnitude that tracks an actual gain step magnitude.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: January 18, 2011
    Assignee: QUALCOMM Incorporated
    Inventors: Linbo Li, Fuyun Ling, Raghuraman Krishnamoorthi
  • Patent number: 7848463
    Abstract: Time filtering channel estimates in a wireless communication system, such as an Orthogonal Frequency Division Multiplex (OFDM) system, can be used to improve the quality of channel estimates. The characteristics of an optimal channel estimate time filter can depend on the manner in which the channel estimate is determined as well as the time correlation of channel estimates. A receiver can implement an adaptive time filter for channel estimates in which the time filter response can vary based on channel estimate parameters. The channel estimate parameters can include the manner of determining channel estimates, a time correlation of channel estimates, and an estimated Doppler frequency. The time filter response can be varied continuously over a range of responses or can be varied discretely over a predetermined number of time filter responses.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: December 7, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Linbo Li, Ashok Mantravadi, Fuyun Ling, Krishna Kiran Mukkavilli
  • Publication number: 20100220821
    Abstract: The disclosure is directed to a receiver, and methods therefor, including an automatic gain control circuit with a first digital variable gain amplifier that outputs digital samples based on a modulated wireless signal, an interference canceller configured to filter the digital samples using a least mean squares algorithm to reduce narrowband interference, and a second DVGA configured to amplify the filtered digital samples.
    Type: Application
    Filed: May 14, 2010
    Publication date: September 2, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: BOJAN VRCELJ, Ashok Mantravadi, Fuyun Ling, Linbo Li, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari, Vinay Murthy
  • Publication number: 20100195754
    Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for antenna switching diversity comprising: identifying the start of an OFDM symbol period; switching from an original antenna to an alternative antenna; calculating a signal quality metric associated with the original antenna and the alternative antenna; and selecting either the original antenna or the alternative antenna for demodulation of a current OFDM symbol based on the calculated signal quality metric. In one aspect, the antenna switching diversity is based on either symbol rate switching or block rate switching, and a selection of one or the other is made.
    Type: Application
    Filed: January 28, 2010
    Publication date: August 5, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: LINBO LI, Ashok Mantravadi
  • Publication number: 20100165851
    Abstract: Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel to facilitate providing seamless reception of the FLO signal, which can be superframe synchronized between RF channels. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.
    Type: Application
    Filed: March 11, 2010
    Publication date: July 1, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Linbo Li, Ashok Mantravadi, Fuyun Ling, Raghuraman Krishnamoorthi
  • Publication number: 20100158168
    Abstract: The disclosure is directed to a mobile communication device that includes automatic gain control (AGC) circuitry and operates in either a tracking mode or an acquisition mode. A received signal is sampled n times to calculate an energy estimate that is used to set the gain control values within the AGC circuitry. The value of n varies depending on whether the handset is operating in the acquisition mode or the tracking mode. Acquisition mode is typically considered to be the mode prior to coarse timing acquisition, also referred to as frame acquisition.
    Type: Application
    Filed: March 9, 2010
    Publication date: June 24, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Vinay Murthy, Linbo Li, Raghuraman Krishnamoorthi
  • Patent number: 7720185
    Abstract: The disclosure is directed to a receiver. The receiver includes an interference canceller configured to filter digital samples produced from a modulated signal transmitted over a wireless channel, and a digital variable gain amplifier (DVGA) configured to amplify the filtered digital samples.
    Type: Grant
    Filed: November 6, 2006
    Date of Patent: May 18, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Bojan Vrcelj, Ashok Mantravadi, Fuyun Ling, Linbo Li, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari, Vinay Murthy
  • Patent number: 7706288
    Abstract: Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel to facilitate providing seamless reception of the FLO signal, which can be superframe synchronized between RF channels. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.
    Type: Grant
    Filed: February 21, 2006
    Date of Patent: April 27, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Linbo Li, Ashok Mantravadi, Fuyun Ling, Raghuraman Krishnamoorthi
  • Patent number: 7702046
    Abstract: The disclosure is directed to a mobile communication device that includes automatic gain control (AGC) circuitry and operates in either a tracking mode or an acquisition mode. A received signal is sampled n times to calculate an energy estimate that is used to set the gain control values within the AGC circuitry. The value of n varies depending on whether the handset is operating in the acquisition mode or the tracking mode. Acquisition mode is typically considered to be the mode prior to coarse timing acquisition, also referred to as frame acquisition.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: April 20, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Vinay Murthy, Linbo Li, Raghuraman Krishnamoorthi
  • Publication number: 20090080378
    Abstract: Methods and apparatus for RF channel switching in a multi-frequency network. In an aspect, a method includes identifying a local area operations infrastructure (LOI) in the multi-frequency network, generating a channel description message that associates at least one descrambling sequence identifier with each RF channel associated with the LOI, respectively, and distributing the CDM over the LOI. In another aspect, a method includes receiving a CDM that associates at least one descrambling sequence identifier with each RF channel available in a LOI, detecting an RF channel switch event that identifies a selected RF channel, determining a selected descrambling sequence identifier from the CDM based on the selected RF channel, switching to the selected RF channel wherein the selected descrambling sequence identifier identifies a selected descrambling sequence to descramble desired content carried on the selected RF channel, and acquiring the desired content on the selected RF channel.
    Type: Application
    Filed: March 26, 2008
    Publication date: March 26, 2009
    Inventors: Binita Gupta, An Mei Chen, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi
  • Publication number: 20090029705
    Abstract: Methods and apparatus for service acquisition in a multi-frequency network. In an aspect, a method is provided for service acquisition in a multi-frequency network. The method includes detecting a service acquisition trigger event and identifying a selected RF channel from an acquisition RF list based on signal strength, wherein the acquisition RF list identifies RF channels in one or more local operations infrastructures (LOIs) of the multi-frequency network. The method also includes acquiring a wide system on the selected RF channel, removing the selected RF channel from the acquisition RF list if the wide system can not be acquired on the selected RF channel, and repeating said operations of identifying, acquiring and removing until the wide system is acquired on the selected RF channel or a system acquisition timeout occurs.
    Type: Application
    Filed: June 18, 2008
    Publication date: January 29, 2009
    Inventors: Binita Gupta, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi
  • Publication number: 20090016380
    Abstract: Methods and apparatus for RF channel switching in a multi-frequency network. In an aspect, a method includes identifying a multiplex set that comprises one or more content flows, wherein the multiplex set is one of a vertical multiplex (VM) set and a unified multiplex (UM) set, generating an overhead message that associates one or more RF carrier frequencies with the one or more content flows, and transmitting the overhead message over the multi-frequency network. An apparatus includes input logic configured to receive an overhead message that associates one or more content flows with one or more RF carrier frequencies, and processing logic configured to detect a channel switch event that identifies a selected content flow, determine a selected RF carrier frequency associated with the selected content flow based on the overhead message, and switch to the selected RF carrier frequency to receive the selected content flow.
    Type: Application
    Filed: March 19, 2008
    Publication date: January 15, 2009
    Inventors: Binita Gupta, An Mei Chen, Devarshi Shah, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi, Taoufik Tani
  • Publication number: 20080261547
    Abstract: Methods and apparatus for RF channel selection in a multi-frequency network. A method includes identifying selected local operations infrastructures (LOIs) and their neighboring LOIs, generating a neighbor description message (NDM) that identifies the selected LOIs and their neighboring LOIs and associates a descrambling sequence identifier with each RF channel of the selected LOIs and their neighboring LOIs, and distributing the NDM over the selected LOIs. An apparatus includes a message decoder to receive an NDM that identifies RF channels of a first LOI and neighboring LOIs, and wherein each RF channel is associated with a descrambling sequence identifier, and processing logic to detect content acquisition failures, determine a list of RF channels and their associated LOIs that carry desired content, and select a selected RF channel that is associated with a selected LOI that carries the most additional content among the associated LOIs.
    Type: Application
    Filed: March 19, 2008
    Publication date: October 23, 2008
    Inventors: Binita Gupta, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi
  • Publication number: 20080253331
    Abstract: Methods and apparatus for RF handoff in a multi-frequency network. A method includes generating seamless and partially seamless handoff tables for multiplexes carried in a current LOI, wherein the seamless and partially seamless handoff tables comprise neighboring RF channels carrying one or more of the multiplexes in the current LOI, detecting a handoff event initiated by acquisition failures on a current RF, selecting a selected RF channel from the seamless and partially seamless handoff tables, and performing a handoff to the selected RF channel. An apparatus includes processing logic configured to generate the seamless and partially seamless handoff tables, detect a handoff event initiated by acquisition failures on a current RF, and select a selected RF channel from the seamless and partially seamless handoff tables. The apparatus also includes channel switch logic configured to perform a handoff to the selected RF channel.
    Type: Application
    Filed: March 19, 2008
    Publication date: October 16, 2008
    Inventors: Binita Gupta, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi
  • Publication number: 20080107217
    Abstract: The disclosure is directed to a receiver. The receiver includes an interference canceller configured to filter digital samples produced from a modulated signal transmitted over a wireless channel, and a digital variable gain amplifier (DVGA) configured to amplify the filtered digital samples.
    Type: Application
    Filed: November 6, 2006
    Publication date: May 8, 2008
    Applicant: QUALCOMM Incorporated
    Inventors: Bojan Vrcelj, Ashok Mantravadi, Fuyun Ling, Linbo Li, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari, Vinay Murthy
  • Publication number: 20080020768
    Abstract: Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel, employing information on current MLC decoding status, to facilitate providing seamless reception of the FLO signal, which can be superframe synchronized between RF channels. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.
    Type: Application
    Filed: July 25, 2007
    Publication date: January 24, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Linbo Li, Ashok Mantravadi, Fuyun Ling, Raghuraman Krishnamoorthi
  • Publication number: 20080020751
    Abstract: Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.
    Type: Application
    Filed: July 25, 2007
    Publication date: January 24, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Linbo Li, Ashok Mantravadi, Fuyun Ling, Raghuraman Krishnamoorthi
  • Publication number: 20070232251
    Abstract: The disclosure is directed to a mobile communication device that includes automatic gain control (AGC) circuitry and operates in either a tracking mode or an acquisition mode. A received signal is sampled n times to calculate an energy estimate that is used to set the gain control values within the AGC circuitry. The value of n varies depending on whether the handset is operating in the acquisition mode or the tracking mode. Acquisition mode is typically considered to be the mode prior to coarse timing acquisition, also referred to as frame acquisition.
    Type: Application
    Filed: April 3, 2006
    Publication date: October 4, 2007
    Inventors: Vinay Murthy, Linbo Li, Raghuraman Krishnamoorthi
  • Publication number: 20070230636
    Abstract: The disclosure is directed to a mobile communication device that includes automatic gain control (AGC) circuitry. Every n samples of the broadcast signals, an energy estimate of the AGC output signal is used to calculate and update a gain control value. Instead of using all n samples occurring subsequent to a previous gain control value update, only a subset of those n samples are used. In particular the first half of the n samples may be discarded in the energy estimate calculation while only the second half of the n samples may be used.
    Type: Application
    Filed: April 3, 2006
    Publication date: October 4, 2007
    Inventors: Vinay Murthy, Linbo Li, Raghuraman Krishnamoorthi