Patents by Inventor Shiquan Wu

Shiquan Wu 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: 20090231191
    Abstract: A method for synchronizing network elements to a global clock derived from the GPS clock acquired by a plurality of base stations. The global clock is distributed to controllers of various networks, and from there to network access devices. The network access devices further distribute the global clock to various wire-line and local wireless networks and from there, to the users served by these networks. The user equipment is enabled with a simple clock discipliner that adjusts the local clock to the global clock, resulting in a reliable synchronization across the converged communication networks.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 17, 2009
    Applicant: Wi-Lan, Inc.
    Inventors: Shiquan Wu, Jung Yee
  • Publication number: 20090176507
    Abstract: A method for calculating the geographical position of a user equipment (UE) unit includes collecting position parameters conveying the relative position of the UE unit from two or more base stations using technologies mandated for the modern wireless networks. Particularly, know (predetermined) signals embedded in the downlink and uplink subframes, such as preambles, pilots, ranging codes are used for determining the coordinates of the UE unit. In addition, the methods and systems proposed here take advantage of the multiple antennas systems mandated at both the UE and BTS.
    Type: Application
    Filed: January 8, 2008
    Publication date: July 9, 2009
    Applicant: Wi-Lan Inc.
    Inventors: Shiquan Wu, Jung Yee
  • Publication number: 20090074098
    Abstract: Systems and methods of combining OFDM and CDMA signals are provided. An OFDM packet data channel is overlaid over CDMA transmissions. The channel is scheduled slotwise between multiple users. In some embodiments, there is a CDMA packet data channel which is scheduled together with the OFDM packet data channel.
    Type: Application
    Filed: November 13, 2008
    Publication date: March 19, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Shiquan Wu, Wen Tong, Peiying Zhu, Ming Jia, Hua Xu, Daniel Boudreau, Jianming Wu, Mo-Han Fong, Keith R. Edwards
  • Patent number: 7471932
    Abstract: Systems and methods of combining OFDM and CDMA signals are provided. An OFDM packet data channel is overlaid over CDMA transmissions. The channel is scheduled slotwise between multiple users. In some embodiments, there is a CDMA packet data channel which is scheduled together with the OFDM packet data channel.
    Type: Grant
    Filed: August 11, 2004
    Date of Patent: December 30, 2008
    Assignee: Nortel Networks Limited
    Inventors: Shiquan Wu, Wen Tong, Peiying Zhu, Ming Jia, Hua Xu, Daniel Boudreau, Jianming Wu, Mo-Han Fong, Keith Edwards
  • Publication number: 20080279135
    Abstract: Infrastructure relays are used to relay signals to multi-antenna receivers where the received signals are then processed using MIMO processing. The transmissions can use spatial multiplexing and/or space time block coding.
    Type: Application
    Filed: May 13, 2008
    Publication date: November 13, 2008
    Inventors: Shalini PERIYALWAR, Shiquan Wu
  • Patent number: 7406060
    Abstract: Infrastructure relays are used to relay signals to multi-antenna receivers where the received signals are then processed using MIMO processing. The transmissions can use spatial multiplexing and/or space time block coding.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: July 29, 2008
    Assignee: Nortel Networks Limited
    Inventors: Shalini Periyalwar, Shiquan Wu
  • Patent number: 7403570
    Abstract: One or more preambles are inserted into frames of Orthogonal Frequency Multiplexing (OFDM)-Multiple Input, Multiple Output (MIMO) signals. The preamble is received by the antennas of a receiver, decoded and compared to known values to provide synchronization, framing, channels estimation, offsets and other corrections to the transmitted signal.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: July 22, 2008
    Assignee: Nortel Networks Limited
    Inventors: Jianglei Ma, Wen Tong, Shiquan Wu
  • Publication number: 20080112361
    Abstract: There is provided a system and method for sharing a wireless spectrum compromising a first transceiver for establishing the communication channels within the allocated bandwidth using a first protocol, a broker for determining the unused bandwidth within the allocated bandwidth, and a second transceiver for establishing the further communication channels within the unused allocated bandwidth using a second protocol. The first protocol is UMTS and the second protocol is WiMax. The broker may monitor UMTS traffic and allocate bandwidth to WiMax traffic whenever resources are idle or traffic are low or allocate bandwidth in dependence upon time division multiplexing, or frequency division multiplexing or may overlap a WiMax signal with a UMTS signal.
    Type: Application
    Filed: November 15, 2006
    Publication date: May 15, 2008
    Inventor: Shiquan Wu
  • Publication number: 20080089223
    Abstract: Systems and methods of combining OFDM and CDMA signals are provided. An OFDM packet data channel is overlaid over CDMA transmissions. The channel is scheduled slotwise between multiple users. In some embodiments, there is a CDMA packet data channel which is scheduled together with the OFDM packet data channel.
    Type: Application
    Filed: December 10, 2007
    Publication date: April 17, 2008
    Inventors: Shiquan Wu, Wen Tong, Peiying Zhu, Ming Jia, Hua Xu, Daniel Boudreau, Jianming Wu, Mo-Han Fong, Keith Edwards
  • Patent number: 7349665
    Abstract: Systems and Methods are provided for relaying wireless signals bi-directionally between user equipment (UE) and base station transceivers (BTS). Various slot types are defined during which a relay node takes on the personality of either the UE or the BTS. In order to implement the relay node with a single transceiver chain, a first switching matrix is used to switch high band and low band RF bandpass filters between receive and transmit paths, and a second switching matrix is used to switch two frequency sources between the receive and transmit path. In this way, a single receive path can function both in the UE and BTS personality, as can the single transmit path.
    Type: Grant
    Filed: December 17, 2003
    Date of Patent: March 25, 2008
    Assignee: Nortel Networks Limited
    Inventors: Peiying Zhu, Wen Tong, Ming Jia, Jianming Wu, Shiquan Wu, Steve Beaudin
  • Patent number: 7336601
    Abstract: An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: February 26, 2008
    Assignee: Nortel Networks Limited
    Inventors: Shiquan Wu, Wen Tong, Leo Strawczynski
  • Publication number: 20080045154
    Abstract: There is provided a system and method of transmitting wireless data. The data signal has a multipath effected upon it and the effected multipath is used to decode the received signal. This is achieved by either passing the signal through a multipath filter prior to transmission or by producing a plurality of reflections of the transmitted signal. In the receiving end, the multipath selector will choose a preferred multipath profile and then form the data vectors for further processing. Systems for multiple input multiple output (MIMO) are thereby possible with fewer receiving antennas than transmitting antennas. Also orthogonal frequency division multiples (OFDM) systems are possible in multipath environments. Combining of beam-forming and MIMO and OFDM systems is also enabled.
    Type: Application
    Filed: August 18, 2006
    Publication date: February 21, 2008
    Inventor: Shiquan WU
  • Patent number: 7319690
    Abstract: Communication signal equalization methods and systems are disclosed. A CDMA signal having a data portion and a known portion including a known or repeated data sequence and received over a multipath communication channel represents a linear convolution between the multipath channel and a transmitted CDMA signal. A channel estimate of the communication channel is determined from the known portion, and the CDMA signal is translated into a new CDMA signal which is a cyclic convolution with the channel estimate. A frequency domain representation of the new CDMA signal is adjusted using the channel estimate to produce a frequency domain representation of an equalized signal.
    Type: Grant
    Filed: August 6, 2004
    Date of Patent: January 15, 2008
    Assignee: Nortel Networks Limited
    Inventors: Shiquan Wu, Wen Tong, Claude Royer
  • Publication number: 20080002568
    Abstract: An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.
    Type: Application
    Filed: September 7, 2007
    Publication date: January 3, 2008
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Shiquan Wu, Wen Tong, Leo Strawczynski
  • Publication number: 20070274408
    Abstract: One or more preambles are inserted into frames of Orthogonal Frequency Multiplexing (OFDM)-Multiple Input, Multiple Output (MIMO) signals. The preamble is received by the antennas of a receiver, decoded and compared to known values to provide synchronization, framing, channels estimation, offsets and other corrections to the transmitted signal.
    Type: Application
    Filed: May 14, 2007
    Publication date: November 29, 2007
    Inventors: Jianglei Ma, Wen Tong, Shiquan Wu
  • Patent number: 7302268
    Abstract: A method of a receiver determining the timing of a signal transmitted in a time-slotted manner, the signal comprising a sequence of information which is repeated at a known interval and has at least a known minimum length. The method performs correlation operations between groups of received slots of information, the groups spaced by the known interval. The groups are moved through the received signal, adding and removing slots, to locate a maximum correlation value sum for the group which should correspond to the timing of the slot. The method also can be used to determine a frequency offset at the receiver and/or an initial phase.
    Type: Grant
    Filed: July 19, 2006
    Date of Patent: November 27, 2007
    Assignee: Soma Networks Inc.
    Inventors: Shiquan Wu, Rene Lamontagne
  • Patent number: 7233625
    Abstract: One or more preambles are inserted into frames of Orthogonal Frequency Multiplexing (OFDM)-Multiple Input, Multiple Output (MIMO) signals. The preamble is received by the antennas of a receiver, decoded and compared to known values to provide synchronization, framing, channels estimation, offsets and other corrections to the transmitted signal.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: June 19, 2007
    Assignee: Nortel Networks Limited
    Inventors: Jianglei Ma, Wen Tong, Shiquan Wu
  • Publication number: 20070097945
    Abstract: The present invention provides a method for generating routing paths in a multi-hop network. The multi-hop network includes a base station, at least one relay station, and at least one non-relay mobile station. The routing paths are paths between the base station and the at least one non-relay mobile station via the at least one relay station. The base station broadcasts a path discovery message (PDM) including a path list with a starting point of the path list being the base station. Each of the relay stations receives the PDM and updates the PDM by adding their own respective node identifier to the path list and broadcasting the updated PDM. The PDMs eventually reach the non-relay mobile station. The non-relay mobile stations reply to the base station by sending the base station the updated path list between the base station and the non-relay mobile station.
    Type: Application
    Filed: July 7, 2006
    Publication date: May 3, 2007
    Inventors: Guo Wang, Shiquan Wu
  • Publication number: 20070036069
    Abstract: An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.
    Type: Application
    Filed: October 17, 2006
    Publication date: February 15, 2007
    Inventors: Shiquan Wu, Wen Tong, Leo Strawczynski
  • Publication number: 20070010196
    Abstract: Infrastructure relays are used to relay signals to multi-antenna receivers where the received signals are then processed using MIMO processing. The transmissions can use spatial multiplexing and/or space time block coding.
    Type: Application
    Filed: October 4, 2005
    Publication date: January 11, 2007
    Inventors: Shalini Periyalwar, Shiquan Wu