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: 9942808
    Abstract: A user equipment (UE) receives, from a wireless access network node of a source cell, a Radio Resource Control (RRC) message identifying a subframe containing information relating to an uplink grant to be sent by a target cell. The UE detects the uplink grant in the identified subframe transmitted by a target wireless access network node of the target cell. The UE sends, in response to the UE successfully accessing the target cell or detecting the information relating to the uplink grant, an RRC message to the target cell to handover from the source cell to the target cell.
    Type: Grant
    Filed: January 23, 2017
    Date of Patent: April 10, 2018
    Assignee: BlackBerry Limited
    Inventors: Zhijun Cai, Chandra Sekhar Bontu, Yi Song
  • Patent number: 9936467
    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: Grant
    Filed: January 29, 2016
    Date of Patent: April 3, 2018
    Assignee: BlackBerry Limited
    Inventors: Youn Hyoung Heo, Zhijun Cai, Andrew Mark Earnshaw, Sean Michael McBeath, Mo-Han Fong
  • Patent number: 9936368
    Abstract: A method at a wireless device outside of base station control, the method comprising: transmitting a device presence signal for a predetermined time period; and listening for a network presence signal sent in response to the device presence signal. Further, a method at a wireless device, the method comprising: listening for a device presence signal; and transmitting a network presence signal in response to the device presence signal.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: April 3, 2018
    Assignee: BlackBerry Limited
    Inventors: William Anthony Gage, Masoud Ebrahimi Tazeh Mahalleh, Biswaroop Mukherjee, Robert Novak, Zhijun Cai
  • Publication number: 20180087499
    Abstract: A method for detecting faults in a pump includes: monitoring suction pressure and discharge pressure time domain signals, filtering the monitored suction pressure time domain signals and the discharge pressure time domain signals via a band pass filter, performing Fast Fourier Transform on the filtered suction pressure time domain signals and the discharge pressure time domain signals for conversion to suction pressure frequency domain signals and discharge pressure frequency domain signals, respectively, performing root mean square calculations on the suction pressure frequency domain signals and the discharge pressure frequency domain signals, analyzing the root mean square suction pressure frequency domain signals and the root mean square discharge pressure frequency domain signals to determine a performance index, and comparing the performance index against a predetermined cavitation threshold to determine whether cavitation exists.
    Type: Application
    Filed: September 23, 2016
    Publication date: March 29, 2018
    Applicant: Caterpillar Inc.
    Inventors: Yanchai Zhang, Venkata Bhagavathi Dandibhotla, Zhijun Cai
  • Publication number: 20180084514
    Abstract: Information is communicated indicating whether a cell on a first carrier of a first type is to be used as a reference cell, wherein the reference cell is at least one selected from among a pathloss reference cell and a timing reference cell, and wherein the first carrier of the first type is part of a carrier aggregation that further includes at least a second carrier of a second, different type.
    Type: Application
    Filed: November 29, 2017
    Publication date: March 22, 2018
    Inventors: Takashi Suzuki, Zhijun Cai, Rene Waraputra Purnadi
  • Patent number: 9923628
    Abstract: A method for recommending a relay node to which a user agent attaches. The method includes recommending the relay node based on a relay node selection rank.
    Type: Grant
    Filed: October 8, 2015
    Date of Patent: March 20, 2018
    Assignee: BlackBerry Limited
    Inventors: James Earl Womack, Yi Yu, Zhijun Cai
  • Publication number: 20180056839
    Abstract: A machine having a work implement includes a sensor connected to the work implement, the sensor providing a signal indicative of a change in acceleration of the work implement. A cycle controller associated with the sensor, the cycle controller disposed to receive the signal and operating to monitor the signal. The cycle controller is programmed and operates to analyze the signal to determine at least a presence and a duration of a change in acceleration of the work implement of the machine with respect to time, compile an actual time trace of the change in acceleration of the work implement, compare the actual time trace with a predefined time trace that represents a work cycle segment, and catalog presence and duration of a work cycle segment when the actual time trace is consistent with the predefined time trace.
    Type: Application
    Filed: August 31, 2016
    Publication date: March 1, 2018
    Applicant: Caterpillar Inc.
    Inventors: Zhijun Cai, Bradley Bomer, Shane C. McBride, Eric Durand, Anders Thomsen
  • Patent number: 9907062
    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: Grant
    Filed: October 24, 2014
    Date of Patent: February 27, 2018
    Assignee: BlackBerry Limited
    Inventors: Sean Michael McBeath, Zhijun Cai, Yi Yu
  • Publication number: 20180054779
    Abstract: Methods, systems and apparatus are provided for camping, assisted serving cell addition or removal, and discontinuous reception (DRX) in networks having a macro cell and at least one assisted serving cell. In other aspects, enhancements to Layer 1 channels and uplink timing alignments are provided in networks having a macro cell and at least one assisted serving cell. In further aspects, assisted serving cell Layer 2 architecture and transport channels are provided in networks having a macro cell and at least one assisted serving cell. In further aspects, collaborated HARQ solutions are provided in networks having a macro cell and at least one assisted serving cell.
    Type: Application
    Filed: October 27, 2017
    Publication date: February 22, 2018
    Applicant: BlackBerry Limited
    Inventors: Zhijun CAI, Yi SONG, Chandra Sekhar BONTU
  • Patent number: 9900820
    Abstract: A local wireless access network node receives a request to offload at least a portion of data traffic for a user equipment from a macro wireless access network node to the local wireless access network node, where the user equipment is to maintain a wireless connection to the macro wireless access network node after the offload. The local wireless access network node sends a response to indicate whether the local wireless access node has accepted or denied the request.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: February 20, 2018
    Assignee: BlackBerry Limited
    Inventors: Shiwei Gao, Yufei Wu Blankenship, Zhijun Cai, Yi Song
  • Patent number: 9900895
    Abstract: A method, system and device are provided for avoiding in-device coexistence interference between different radio technologies deployed in adjacent bands on the same device by controlling and separating the LTE signaling and the non-LTE signaling using dedicated time intervals to separate LTE signaling from non-LTE signaling. In addition, coexistence mode handover procedures are provided which use threshold-based triggering events to avoid coexistence interference and to prevent ping-pong effects by establishing a “keeping time” parameter so that a non-interfering network node does not switch back to an interfering network node after handoff.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: February 20, 2018
    Assignee: BlackBerry Limited
    Inventors: Changhoi Koo, Jun Li, Zhijun Cai
  • Patent number: 9888484
    Abstract: A system and method of receiving a channel state information reference signal (CSI-RS) is presented. At a user equipment, a first CSI-RS transmitted from a base station is received. In some implementations, the first CSI-RS is transmitted at a first periodicity using a first set of antenna ports. At the user equipment, a second CSI-RS transmitted from the base station is received. In some implementations, the second CSI-RS is transmitted at a second periodicity using a second set of antenna ports. At least one of the first CSI-RS and the second CSI-RS is used to perform channel measurement.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: February 6, 2018
    Assignee: BlackBerry Limited
    Inventors: Mo-Han Fong, Dongsheng Yu, Hua Xu, Robert Novak, Shiguang Guo, Zhijun Cai, Youn Hyoung Heo
  • Patent number: 9883501
    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: Grant
    Filed: November 19, 2015
    Date of Patent: January 30, 2018
    Assignee: BlackBerry Limited
    Inventors: Hua Xu, Yongkang Jia, Zhijun Cai, Youn Hyoung Heo, Andrew Mark Earnshaw, Mo-Han Fong, Sean Michael McBeath, Robert Mark Harrison
  • Publication number: 20180027532
    Abstract: A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource allocated by a resource grant within a multi-carrier communication system wherein resource grants are specified by control channel element (CCE) subset candidates wherein the carriers used for data transmission and reception are configured carriers, the method comprising the steps of receiving activation signals specifying active and deactivated carriers from among the configured carriers, for active carriers (i) identifying a number of CCE subset candidates to decode and (ii) decoding up to the identified number of CCE subset candidates in an attempt to identify the resource grant; and for deactivated carriers, ignoring CCE subset candidates associated with the deactivated carriers.
    Type: Application
    Filed: August 11, 2017
    Publication date: January 25, 2018
    Inventors: Sean Michael McBeath, Andrew Mark Earnshaw, Mo-Han Fong, Youn Hyoung Heo, Zhijun Cai
  • Publication number: 20180027529
    Abstract: A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource allocated by a resource grant within a multi-carrier communication system wherein resource grants are specified by control channel element (CCE) subset candidates wherein the carriers used for data transmission and reception are configured carriers, the method comprising the steps of receiving activation signals specifying active and deactivated carriers from among the configured carriers, for active carriers (i) identifying a number of CCE subset candidates to decode and (ii) decoding up to the identified number of CCE subset candidates in an attempt to identify the resource grant; and for deactivated carriers, ignoring CCE subset candidates associated with the deactivated carriers.
    Type: Application
    Filed: August 11, 2017
    Publication date: January 25, 2018
    Inventors: Sean Michael McBeath, Andrew Mark Earnshaw, Mo-Han Fong, Youn Hyoung Heo, Zhijun Cai
  • Publication number: 20180027531
    Abstract: A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource allocated by a resource grant within a multi-carrier communication system wherein resource grants are specified by control channel element (CCE) subset candidates wherein the carriers used for data transmission and reception are configured carriers, the method comprising the steps of receiving activation signals specifying active and deactivated carriers from among the configured carriers, for active carriers (i) identifying a number of CCE subset candidates to decode and (ii) decoding up to the identified number of CCE subset candidates in an attempt to identify the resource grant; and for deactivated carriers, ignoring CCE subset candidates associated with the deactivated carriers.
    Type: Application
    Filed: August 11, 2017
    Publication date: January 25, 2018
    Inventors: Sean Michael McBeath, Andrew Mark Earnshaw, Mo-Han Fong, Youn Hyoung Heo, Zhijun Cai
  • Publication number: 20180027530
    Abstract: A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource allocated by a resource grant within a multi-carrier communication system wherein resource grants are specified by control channel element (CCE) subset candidates wherein the carriers used for data transmission and reception are configured carriers, the method comprising the steps of receiving activation signals specifying active and deactivated carriers from among the configured carriers, for active carriers (i) identifying a number of CCE subset candidates to decode and (ii) decoding up to the identified number of CCE subset candidates in an attempt to identify the resource grant; and for deactivated carriers, ignoring CCE subset candidates associated with the deactivated carriers.
    Type: Application
    Filed: August 11, 2017
    Publication date: January 25, 2018
    Inventors: Sean Michael McBeath, Andrew Mark Earnshaw, Mo-Han Fong, Youn Hyoung Heo, Zhijun Cai
  • Patent number: 9876618
    Abstract: A system and method for transmitting uplink channels for a plurality of uplink component carriers(UL CCs). Based upon a total transmit power exceeding a maximum allowed power, a transmit power is reduced for uplink channel transmissions that comprise Uplink Channel Information (UCI); and transmit power is not reduced for one or more other uplink channels that do not include comprise Uplink Channel Information (UCI). The uplink channel transmissions and the one or more other uplink channels are simultaneously transmitted in multiple uplink (UL) component carriers (CCs).
    Type: Grant
    Filed: February 8, 2016
    Date of Patent: January 23, 2018
    Assignee: BlackBerry Limited
    Inventors: Youn Hyoung Heo, Mo-Han Fong, Michael Eoin Buckley, Andrew Mark Earnshaw, Zhijun Cai
  • Publication number: 20170374660
    Abstract: In some implementations, a method in a user equipment (UE) for supporting time division duplex (TDD) and frequency division duplex (FDD) joint carrier aggregation (CA) includes receiving a Physical Uplink Control Channel (PUCCH) resource allocation from an evolved NodeB (eNB). The PUCCH resource allocation includes a first PUCCH configuration for a first subframe and a second PUCCH configuration for a second subframe, and the second PUCCH configuration is different than the first PUCCH configuration. The UE transmits a first group of Hybrid Automatic Repeat reQuest (HARQ) bits based on the first PUCCH configuration in the first subframe. The UE transmits a second group of HARQ bits based on the second PUCCH configuration in the second subframe.
    Type: Application
    Filed: July 7, 2017
    Publication date: December 28, 2017
    Applicant: BlackBerry Limited
    Inventors: Yiping Wang, Zhijun Cai, Yi Song
  • Patent number: 9854522
    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: Grant
    Filed: September 12, 2016
    Date of Patent: December 26, 2017
    Assignee: BlackBerry Limited
    Inventors: Zhijun Cai, James Earl Womack