Patents by Inventor Khurram Ali Rizvi

Khurram Ali Rizvi 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: 7443829
    Abstract: The present invention provides a method of improving the performance of a CDMA based wireless network, such as a 3G cellular network for example. Interference cancellation is effectively performed earlier by using the channel request such as a reservation packet from a mobile terminal to estimate interference from that mobile on existing mobile users and interference on the mobile from existing mobile users, by determining the relative transmission timing of the new mobiles channel request compared with the transmission timings of the existing mobiles. The base station determine the cross-correlation between the codes already assigned to the existing users and the code to be allocated to the new user in order to determine an interference measure. This interference can then be cancelled from the new mobile when its data packets are received.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: October 28, 2008
    Assignee: Toshiba Corporation
    Inventors: Khurram Ali Rizvi, Yuk C Chow, Tomoya Horiguchi
  • Patent number: 7386032
    Abstract: Spread spectrum receiver architectures and methods are described for reducing interference, particularly the interference observed at a user-end terminal in a W-CDMA 3G mobile communications system. Interpath interference which arises due to non-zero cross and auto correlation of more than one spreading code is suppressed by estimating a transmitted signal stream, or a plurality of such signal streams in the case of a plurality of multipath components, respreading this estimated signal and subtracting non-orthogonal interference contributions from a received signal. The techniques provide an improved bit error rate or equivalently, enhanced capacity for a digital mobile communications network.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: June 10, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Michael Philip Fitton, Anthony Craig Dolwin, Khurram Ali Rizvi, Yuk Ching Chow, Mohamed Rafiq Ismail
  • Patent number: 7295597
    Abstract: A multicode receiver for receiving data carried by a plurality of spread spectrum signals having a corresponding plurality of spreading codes, the spreading codes being substantially mutually orthogonal, the receiver having intercode interference suppression, the receiver including a multicode spread spectrum receiver to provide a set of data estimates having a plurality of estimates of data carried by the plurality of spread spectrum signals, one estimate for each spread spectrum signal, a plurality of respreaders to respread the plurality of data estimates, a plurality of interference suppressers, at least one for each of the plurality of spreading codes, each at least one interference suppresser for each code being configured to suppress respread data estimates for the spread spectrum signals of the other codes, from a received signal, a plurality of rake fingers each having the plurality of interference suppressers, and a plurality of rake combiners, one for each of the plurality of spreading codes.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: November 13, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Michael Philip Fitton, Khurram Ali Rizvi, Yuk Ching Chow
  • Publication number: 20040028013
    Abstract: Spread spectrum receiver architectures and methods are described for reducing interference, particularly the interference observed at a user-end terminal in a W-CDMA 3G mobile communications system. Interpath interference which arises due to non-zero cross and auto correlation of more than one spreading code is suppressed by estimating a transmitted signal stream, or a plurality of such signal streams in the case of a plurality of multipath components, respreading this estimated signal and subtracting non-orthogonal interference contributions from a received signal. The techniques provide an improved bit error rate or equivalently, enhanced capacity for a digital mobile communications network.
    Type: Application
    Filed: January 24, 2003
    Publication date: February 12, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Michael Philip Fitton, Anthony Craig Dolwin, Khurram Ali Rizvi, Yuk Ching Chow, Mohamed Rafiq Ismail
  • Publication number: 20040017843
    Abstract: Multicode spread spectrum receiver architectures and methods are described for reducing interference, particularly the interference observed at a user-end terminal in a W-CDMA 3G mobile communications system. Interpath interference which arises due to non-zero cross and auto correlation of more than one spreading code is suppressed by estimating a transmitted signal stream, or a plurality of such signal streams in the case of a plurality of multipath components, respreading this estimated signal and subtracting non-orthogonal interference contributions from a received signal. The techniques provide an improved bit error rate or equivalently, enhanced capacity for a digital mobile communications network.
    Type: Application
    Filed: January 24, 2003
    Publication date: January 29, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Michael Philip Fitton, Khurram Ali Rizvi, Yuk Ching Chow