Patents by Inventor Junjie Zhu

Junjie Zhu 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).

  • Publication number: 20040004934
    Abstract: The present invention relates to methods and devices for receiving signals in a Wireless Local Area Network (wireless LAN, or WLAN), particularly in the case that the signals are Orthogonal Frequency Division Multiplexed (OFDM) signals. A frequency offset estimation apparatus for an OFDM receiver is disclosed, having: means for determining a first frequency offset having means for determining the correlation of corresponding samples of two received preamble symbol samples a first predetermined delay duration apart; means for determining a second frequency offset having means for determining the correlation of corresponding samples of two received preamble symbol samples a second predetermined delay duration apart, said second delay duration being different from said first delay duration; and means for combining said first and second frequency offsets in order to determine said frequency offset estimation.
    Type: Application
    Filed: March 27, 2003
    Publication date: January 8, 2004
    Applicant: Oki Techno Centre (Singapore) Pte Ltd
    Inventors: Junjie Zhu, Noriyoshi Ito
  • Publication number: 20040004935
    Abstract: The present invention relates to methods and devices for receiving signals in a Wireless Local Area Network (wireless LAN, or WLAN), particularly in the case that the signals are Orthogonal Frequency Division Multiplexed (OFDM) signals. A frequency tracking apparatus for an OFDM receiver is disclsoed having means for determining the correlation of corresponding samples of two received pilot carrier symbols, one said sample delayed a predetermined duration with respect to the other; means for integrating said correlation over an integration window and means for determining a frequency tracking error from the sum of said integration.
    Type: Application
    Filed: March 27, 2003
    Publication date: January 8, 2004
    Applicant: Oki Techno Centre (Singapore) Pte Ltd.
    Inventors: Junjie Zhu, Noriyoshi Ito
  • Publication number: 20040005018
    Abstract: The present invention relates to methods and devices for receiving signals in a Wireless Local Area Network (wireless LAN, or WLAN), particularly in the case that the signals are Orthogonal Frequency Division Multiplexed (OFDM) signals. A signal detection apparatus is disclosed for an OFDM receiver, having: means for determining the correlation of corresponding samples of two received preamble symbol samples, one said sample delayed a predetermined duration with respect to the other; signal detection being indicated when the correlation is greater than or equal to a threshold; wherein the threshold is dependent on the signal power of the received preamble symbols.
    Type: Application
    Filed: March 27, 2003
    Publication date: January 8, 2004
    Applicant: Oki Techno Centre (Singapore) Pte Ltd
    Inventors: Junjie Zhu, Noriyoshi Ito
  • Publication number: 20040004933
    Abstract: The present invention relates to methods and devices for receiving signals in a Wireless Local Area Network (wireless LAN, or WLAN), particularly in the case that the signals are Orthogonal Frequency Division Multiplexed (OFDM) signals. An Automatic Gain Control apparatus for an OFDM receiver is disclosed, having means for determining the average power of received preamble symbols in order to set an appropriate AGC level, means for determining a first AGC level based on the average power of a first number of symbols and means for determining a second AGC level based on the average power of a second number of subsequent symbols.
    Type: Application
    Filed: March 27, 2003
    Publication date: January 8, 2004
    Applicant: Oki Techno Centre (Singapore) Pte Ltd, a company organized and existing under the laws of singapore
    Inventors: Junjie Zhu, Noriyoshi Ito
  • Publication number: 20040005022
    Abstract: The present invention relates to methods and devices for receiving signals in a Wireless Local Area Network (wireless LAN, or WLAN), particularly in the case that the signals are Orthogonal Frequency Division Multiplexed (OFDM) signals. A symbol timing apparatus for an OFDM receiver is disclosed having: means for determining the correlation of corresponding samples of two received preamble symbols, one said sample delayed a predetermined duration with respect to the other; means for determining the maximum correlation value within a predetermined integration window, said maximum value indicating the start of a symbol; wherein the integration window duration is not equal to said delay duration.
    Type: Application
    Filed: March 27, 2003
    Publication date: January 8, 2004
    Applicant: Oki Techno Centre (Singapore) Pte Ltd.
    Inventors: Junjie Zhu, Noriyoshi Ito
  • Publication number: 20020039383
    Abstract: A single frequency relay station receives a signal from a master station, and retransmits it. Before retransmitting the signal, the relay station uses a digital filter to subtract from the signal components which arise from multipath interference and coupling interference. The coefficients used by the digital filter are derived from characteristics of the multipath interference and the overall transfer function of the relay station. These are derived by turning off the retransmission, so that the multipath interference can be estimated from the received signal, and commencing the retransmission again, to determine the transfer function. A simplified inverse fast Fourier transform is used to simplify the calculations.
    Type: Application
    Filed: June 18, 2001
    Publication date: April 4, 2002
    Applicant: Oki Techno Centre Pte Ltd.
    Inventors: Junjie Zhu, Hiroki Sugimoto, Hideto Ikeda