Patents by Inventor Zhijun Cai

Zhijun Cai 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: 10021555
    Abstract: A method, network node, and user equipments for providing parameters to a first user equipment served by the network element, the parameters describing at least a second user equipment for the purpose of the first user equipment initiating a device to device proximity discovery service with the second user equipment, the method collecting information for user equipments desiring device to device proximity discovery; creating a candidate user equipment list for a candidate tier based on the collected information at the network element, wherein each candidate tier comprises one or more thresholds based on timing advance values in use at the first or the at least the second user equipment; and providing the parameters describing at least a second user equipment to the first user equipment.
    Type: Grant
    Filed: November 9, 2015
    Date of Patent: July 10, 2018
    Assignee: BlackBerry Limited
    Inventors: Joon Beom Kim, Changhoi Koo, Zhijun Cai
  • Patent number: 10020925
    Abstract: A method and apparatus for dynamic acknowledgement repetition for a downlink medium access control packet data unit transmission ‘MAC PDU’ requiring multiple acknowledgements, the method having the steps of: receiving the downlink MAC PDU requiring multiple acknowledgements; and utilizing a differentiating factor and acknowledgement scheme, sending the multiple acknowledgements.
    Type: Grant
    Filed: January 29, 2015
    Date of Patent: July 10, 2018
    Assignee: BlackBerry Limited
    Inventors: Takashi Suzuki, Zhijun Cai, James Earl Womack
  • Patent number: 10015742
    Abstract: A system and method are disclosed for providing uplink timing synchronization during DRX operation in a wireless communication system.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: July 3, 2018
    Assignee: GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.
    Inventors: James Earl Womack, Yi Yu, Zhijun Cai
  • Patent number: 10015758
    Abstract: Systems and methods for controlling sounding reference signal transmission are provided; a user equipment starts transmitting the sounding reference signal in anticipation of uplink data transmission, and then discontinues transmitting the sounding reference signal after completion of uplink data transmission.
    Type: Grant
    Filed: February 10, 2017
    Date of Patent: July 3, 2018
    Assignee: BlackBerry Limited
    Inventors: James Earl Womack, Zhijun Cai
  • Publication number: 20180184386
    Abstract: A method for reporting power headroom-related information for a plurality of aggregated carriers. The method includes reporting in a bitmap the power headroom-related information for a number of the aggregated carriers that is less than or equal to the total number of aggregated carriers, wherein the power headroom-related information is one of a power headroom for at least one of the aggregated carriers and a path loss for at least one of the aggregated carriers.
    Type: Application
    Filed: February 21, 2018
    Publication date: June 28, 2018
    Inventors: Youn Hyoung Heo, Zhijun Cai, Andrew Mark Earnshaw, Sean Michael McBeath, Mo-Han Fong
  • Publication number: 20180167922
    Abstract: A method and system to signal transmission layers or dedicated reference signal ports to be used in a multiple input multiple output system, the method including providing a downlink control signal containing information for transmission layers or dedicated reference signal ports utilized, the dedicated reference signal ports being associated with the transmission layers; and using the information to demodulate data on each transmission layer.
    Type: Application
    Filed: January 29, 2018
    Publication date: June 14, 2018
    Applicant: BlackBerry Limited
    Inventors: Zhijun Cai, Sean Michael McBeath, Hua Xu, Yongkang Jia, Youn Hyoung Heo, Andrew Mark Earnshaw, Mo-Han Fong, Robert Mark Harrison
  • Patent number: 9998973
    Abstract: A first wireless access network node receives common radio resource configuration information of a second wireless access network node. A data offload request is sent to the second wireless access network node to perform a data offload for a user equipment (UE) attached to the first wireless access network node.
    Type: Grant
    Filed: August 24, 2015
    Date of Patent: June 12, 2018
    Assignee: BlackBerry Limited
    Inventors: Shiwei Gao, Yufei Wu Blankenship, Zhijun Cai, Yi Song
  • Patent number: 9986524
    Abstract: Described herein is a system with a first network element and a second network element. The first network element contains a processor configured to synchronize with the second network element; and maintain synchronization with the second network element. The first network element is a small cell eNB and the second network element is one of the following: a macro cell enhanced node-B (eNB); or a small cell eNB.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: May 29, 2018
    Assignee: BlackBerry Limited
    Inventors: Hua Xu, Shiwei Gao, Zhijun Cai, Chandra Sekhar Bontu, Yi Song, Yajun Zhu
  • Publication number: 20180146427
    Abstract: Methods of combining semi-persistent resource allocation and dynamic resource allocation are provided. Packets, such as VoIP packets, are transmitted on the uplink and downlink using respective semi-persistent resources. For each mobile device, awake periods and sleep periods are defined. The semi-persistent resources are aligned with the awake periods so that most of the time the mobile device can turn off its wireless access radio during the sleep periods. In addition, signalling to request, and to allocate, resources for additional packets are transmitted during the awake periods, and the resources allocated for the additional packets are within the awake windows.
    Type: Application
    Filed: November 21, 2017
    Publication date: May 24, 2018
    Inventors: Zhijun Cai, James Earl Womack
  • Publication number: 20180146464
    Abstract: A method for designating, by a user agent supporting multiple carriers in a wireless communication network, one assigned carrier as an anchor carrier, at least one assigned carrier as an inactive carrier, and at least one assigned carrier as an active carrier. The method can also include receiving a command from an enhanced node B causing a first carrier to transition from an inactive carrier to an active carrier. Additionally, the method can include responsive to reception of the command, monitoring a control channel corresponding to the first carrier. Further, the method can also include receiving downlink control information (DCI) via the control channel. The method can also include responsive to reception of the DCI, starting a timer, and deactivating the first carrier at the expiration of the timer.
    Type: Application
    Filed: January 22, 2018
    Publication date: May 24, 2018
    Applicant: BlackBerry Limited
    Inventors: Sean Michael MCBEATH, Zhijun CAI, Yi YU
  • Patent number: 9973901
    Abstract: In some implementations, a method in a user equipment (UE) for supporting group communication service includes receiving, from a base station, a group communication on a Physical Downlink Shared Channel (PDSCH). The UE determines a first Hybrid Automatic Repeat reQuest (HARQ) information that corresponds to the group communication on the PDSCH. The UE transmits the first HARQ information. In some implementations, the UE determines a group Channel State Information (CSI) for a group communication that is transmitted by a base station on a PDSCH. The UE determines a unicast CSI for a unicast communication that is transmitted by the base station on the PDSCH. The UE transmits the group CSI. The UE transmits the unicast CSI.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: May 15, 2018
    Assignee: BlackBerry Limited
    Inventors: Zhijun Cai, Chandra Sekhar Bontu, Yi Song
  • Publication number: 20180131495
    Abstract: A method and apparatus for dynamic acknowledgement repetition for a downlink medium access control packet data unit transmission ‘MAC PDU’ requiring multiple acknowledgements, the method having the steps of: receiving the downlink MAC PDU requiring multiple acknowledgements; and utilizing a differentiating factor and acknowledgement scheme, sending the multiple acknowledgements.
    Type: Application
    Filed: December 15, 2017
    Publication date: May 10, 2018
    Applicant: BlackBerry Limited
    Inventors: Takashi Suzuki, Zhijun Cai, James Earl Womack
  • Patent number: 9960881
    Abstract: A method for determining a Modulation and Coding Scheme (MCS) and power control includes determining an error rate of a communication channel between the UA and at least one of the base station and the RN. When the error rate is below a first threshold, the method includes at least one of increasing the MCS, and reducing a transmission power of the UA. When the error rate is above a second threshold, the method includes at least one of decreasing the MCS, and increasing a transmission power of the UA.
    Type: Grant
    Filed: April 28, 2017
    Date of Patent: May 1, 2018
    Assignee: BlackBerry Limited
    Inventors: Rose Qingyang Hu, Yi Yu, Zhijun Cai, James Womack, Yi Song, Chandra S. Bontu, Mo-Han Fong
  • Patent number: 9961715
    Abstract: Systems, methods, and apparatuses for radio resource control (RRC) signaling in wireless communication networks with data offload are provided. The radio configuration messages from a small cell to a dual connection UE may be sent by an overlay macro E-UTRAN node-B (eNB). The small cell may send the RRC messages to the macro-eNB first via a backhaul link, and the macro-eNB then transmits the messages to the UE. In some implementations, the radio configuration messages from a small cell to a dual connection UE may be sent directly from the small cell. In some other implementations, some of the RRC messages may be sent selectively to/from either the macro-cell or the small cell, or to/from both the macro-cell and the small cell. The type of RRC messages sent over the small cell and/or the macro-cell may be preconfigured or predetermined.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: May 1, 2018
    Assignee: BlackBerry Limited
    Inventors: Shiwei Gao, Yufei Wu Blankenship, Zhijun Cai
  • Patent number: 9945375
    Abstract: A method for automatic tuning of a reference model for a fracking rig pump is provided. The method includes determining, at a processor connected to a fracking rig pump, a current choke area associated with the fracking rig pump based upon at least a maximum power and a maximum pressure obtained from the fracking rig pump for a pump speed of the fracking rig pump, obtaining a pump power and a pump pressure for the current choke area based upon at least a reference model for the fracking rig pump stored in a memory device coupled to the processor, determining a pressure difference between the maximum pressure obtained from the fracking rig pump and the pump pressure, determining a power difference between the maximum power obtained from the fracking rig pump and the pump power obtained from the reference model, and providing an updated choke area to the reference model.
    Type: Grant
    Filed: January 20, 2016
    Date of Patent: April 17, 2018
    Assignee: Caterpillar Inc.
    Inventors: Yanchai Zhang, Zhijun Cai, Venkata Dandibhotla, Evan Jacobson, Koti Padarthy
  • Patent number: 9949289
    Abstract: A network element in a first cell in a wireless telecommunication network is provided. The network element comprises a processor configured such that the network element provides uplink and downlink grants in the first cell, wherein the first cell is a low-power cell within the coverage area of a second, high-power cell, and wherein the first cell acts as a secondary cell and the second cell acts as a primary cell in a carrier aggregation mode, and wherein at least one uplink control signal is received by one of only the first cell or both the first cell and the second cell.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: April 17, 2018
    Assignee: BlackBerry Limited
    Inventors: Yi Song, Chandra Sekhar Bontu, Zhijun Cai
  • Publication number: 20180100496
    Abstract: A method for detecting a leak in a pump comprises: monitoring discharge pressure time domain signals of the pump; monitoring piston position time domain signals for each piston of a plurality of pistons; filtering the monitored discharge pressure time domain signals and the monitored piston position time domain signals of each piston of the plurality of pistons via a band pass filter; determining, at each pump revolution for each piston, a sum of product of the filtered discharge pressure time domain signals and the filtered piston position time domain signals; determine, at each pump revolution for each piston, an absolute value of each sum; determining, at each pump revolution, a largest absolute value of the determined absolute values; determining a corresponding piston of the plurality of pistons associated with the largest absolute value; and determining a cylinder of the pump associated with the determined corresponding piston as leaking.
    Type: Application
    Filed: October 6, 2016
    Publication date: April 12, 2018
    Applicant: Caterpillar Inc.
    Inventors: Yanchai Zhang, Venkata Bhagavathi Dandibhotla, Zhijun Cai, Zhaoxu Dong, Xuefei Hu
  • Publication number: 20180103385
    Abstract: In some examples, a wireless access network node communicates with user equipments (UEs) in a plurality of sets of subframes, the plurality of sets of subframes comprising a first set of subframes and a second set of subframes. The wireless access network node performs dynamic power control of a transmission of the wireless access network node in the first set of subframes, and does not perform dynamic power control of a transmission of the wireless access network node in the second set of subframes.
    Type: Application
    Filed: November 17, 2017
    Publication date: April 12, 2018
    Inventors: Yajun Zhu, Hua Xu, Zhijun Cai, Shiwei Gao, Yufei Wu Blankenship, Vahid Pourahmadi
  • Patent number: 9941997
    Abstract: A method and system, in a long term evolution architecture utilizing adaptive modulation and coding requiring periodic channel quality indication reports, the method having the steps of: waiting for an idle channel indication; and upon detection of the idle channel indication, decreasing the rate of periodic channel quality indication reports.
    Type: Grant
    Filed: July 18, 2016
    Date of Patent: April 10, 2018
    Assignee: BlackBerry Limited
    Inventors: Zhijun Cai, James Earl Womack
  • Patent number: RE46821
    Abstract: A method and device for handling hybrid automatic repeat request (‘HARQ’) operations during transmission mode changes, the method detecting a transmission mode change; and manipulating an HARQ process buffer based on the detecting. Further, a method and network element for handling hybrid automatic repeat request (‘HARQ’) operations during transmission mode changes, the method checking when a user equipment is in a transmission mode uncertainty window; and blocking communications to the user equipment or utilizing a downlink control information format 1A for communications to the user equipment.
    Type: Grant
    Filed: November 5, 2015
    Date of Patent: May 1, 2018
    Assignee: BlackBerry Limited
    Inventors: Mark Earnshaw, Takashi Suzuki, Zhijun Cai, Youn Hyoung Heo