Patents by Inventor Yunjian Jia

Yunjian Jia 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: 20120134335
    Abstract: A transmitting station having plural antennas includes: a control information calculation unit that calculates control information for use by plural receiving stations according to a multi-user MIMO data transmission scheme; a control information transmission parameter calculation unit that calculates a control information transmission parameter based on spatial channel related information; and a control information transmission signal creation unit that creates a control information transmission signal, using the control information transmission parameter and a pilot signal. A resource element mapping unit maps control information transmission signals onto corresponding resource elements for transmission. On the other hand, the receiving stations each include a control information acquisition unit that acquires plural pieces of control information signaled on the corresponding resource elements, acquire control information destined for each receiving station, and demodulate received signals.
    Type: Application
    Filed: August 12, 2009
    Publication date: May 31, 2012
    Applicant: HITACHI, LTD.
    Inventors: Yunjian Jia, Takashi Yano, Shigenori Hayase
  • Publication number: 20120094710
    Abstract: Disclosed are a communication control device, a communication control method and the system thereof, which provide efficient multi-base station joint services in a mobile communication system using dynamic clustering. Optimal base station clustering is chosen according to the communication state between a terminal and each base station. The communication control device connects with multiple base stations through a network, and clusters the multiple base stations dynamically so that the clustered multiple base stations can provide services for the mobile terminal in union. The communication control device comprises: an interface, connecting with multiple base stations, receiving channel state information related to the mobile terminal from each base station; a memory unit, storing the channel state information of the mobile terminal received from the interface; a control unit, clustering each base station dynamically according to the channel state information of the mobile terminal stored in the memory unit.
    Type: Application
    Filed: April 29, 2010
    Publication date: April 19, 2012
    Applicant: HITACHI, LTD.
    Inventors: Yunjian Jia, Kenzaburo Fujishima, Hideya Yoshiuchi, Peng Yang, Yuanchen Ma, Lu Geng, Sheng Zhou, Zhisheng Niu, Jie Gong
  • Publication number: 20120087265
    Abstract: A frame time having a certain period of time is divided into: a time period (for inter-base-station time division multiplex communication) in which one of the base stations has a transmission right in the simultaneous transmission and carries out inter-base-station time division multiplex communication so as to avoid interference between the base stations; and a time period (for inter-base-station simultaneous communication) for communication which is simultaneously carried out between the plurality of base stations. Furthermore, the time periods are switched for the communication.
    Type: Application
    Filed: April 27, 2009
    Publication date: April 12, 2012
    Applicant: HITACHI, LTD.
    Inventors: Tsuyoshi Tamaki, Takashi Yano, Yunjian Jia
  • Patent number: 8155219
    Abstract: A method for suppressing the peak-to-average power ratio (PAPR) while limiting deterioration in signal characteristics in wireless communication devices utilizing wireless communication methods (OFDM method, MIMO method) for multiplexing and sending multiple signals. A weight calculator unit sets a large weight for transmit signals whose channel quality is poor, relative to the weight of each base component based on the acquired channel quality. A peak detector unit detects the peak from the signal string after unitary conversion, and extracts a distortion component to apply for suppressing the peak. A peak suppression signal generation unit calculates the peak signal from the distortion component and weight of each base component, to add to each base component, and adds the peak suppression signal to each base component prior to unitary transformation.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: April 10, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Shigenori Hayase, Takashi Yano, Masaaki Shida, Keisuke Yamamoto, Yunjian Jia
  • Publication number: 20120014272
    Abstract: A communication control server of the present invention comprises: a network interface; a memory unit in which a cluster information table and a channel state information table are stored; a channel state information recovery unit acquiring a feedback message of a user equipment within a cluster from a base station via a network interface, wherein the cluster information table holds a joint codebook shared by the base stations within the cluster, wherein the joint codebook holds an identifier for determining channel state information and a distribution of the channel state information, and wherein the feedback message includes an identifier corresponding to the channel state information of the user equipment.
    Type: Application
    Filed: May 12, 2011
    Publication date: January 19, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Sheng ZHOU, Yunjian Jia, Peng Yang, Jie Gong, Zhisheng Niu, Lu Geng
  • Publication number: 20110242962
    Abstract: The present invention achieves a communication speed close to a theoretical limitation with suppressing a computing amount and without increasing protocol overhead. In a multiuser MIMO wireless communication method according to the present invention, a receive weight matrix is determined based on a channel matrix, the channel matrix is updated by a product of the receive weight matrix and a channel matrix, a transmitted signal is generated in a ZF-DPC method based on the updated channel matrix and transmitted, and the receive weight matrix is multiplied with a received signal and then subjected to a DPC decoding. A method of determining a receive weight matrix is to take a conjugate transpose matrix of a left singular matrix obtained when subjecting the channel matrix to a singular value decomposition.
    Type: Application
    Filed: October 28, 2008
    Publication date: October 6, 2011
    Applicant: HITACHI, LTD.
    Inventors: Shigenori Hayase, Takashi Yano, Yunjian Jia
  • Publication number: 20100034078
    Abstract: In a method by which a base station detects a random access signal transmitted by a user equipment to send a transmission request to the base station in uplinks, the base station omits a MF used only to detect the random access signal, or Fourier transform and inverse Fourier transform meeting the random access signal, and uses a Fourier transform unit for data reception to detect the random access signal. Using output of the Fourier transform unit for data reception, which transmits all received signals to frequency region signals, it is judged whether a random access signal is received by a power pattern of bands allocated to the random access signals in one transmission time interval.
    Type: Application
    Filed: August 5, 2009
    Publication date: February 11, 2010
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Yunjian JIA, Katsuhiko TSUNEHARA
  • Publication number: 20090307567
    Abstract: The error correction capability for wireless communication carried out involving propagation path fluctuation in time and frequency selectivity can be improved. A soft decision likelihood value inputted to an error correction decoder is multiplied by a weight determined according to the distance between the data symbol and pilot symbol corresponding to the soft decision likelihood value. Namely, the soft decision bit likelihood value corresponding to the data symbol is weighted according to the distances in time or frequency between the pilot symbol and data symbol. The weight is made smaller when the distance in time or frequency is larger.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 10, 2009
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Katsuhiko Tsunehara, Yunjian Jia
  • Publication number: 20090060070
    Abstract: A method for suppressing the peak-to-average power ratio (PAPR) while limiting deterioration in signal characteristics in wireless communication devices utilizing wireless communication methods (OFDM method, MIMO method) for multiplexing and sending multiple signals. A weight calculator unit sets a large weight for transmit signals whose channel quality is poor, relative to the weight of each base component based on the acquired channel quality. A peak detector unit detects the peak from the signal string after unitary conversion, and extracts a distortion component to apply for suppressing the peak. A peak suppression signal generation unit calculates the peak signal from the distortion component and weight of each base component, to add to each base component, and adds the peak suppression signal to each base component prior to unitary transformation.
    Type: Application
    Filed: July 18, 2008
    Publication date: March 5, 2009
    Inventors: Shigenori Hayase, Takashi Yano, Masaaki Shida, Keisuke Yamamoto, Yunjian Jia