Patents by Inventor Xixian Chen

Xixian Chen 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: 9578583
    Abstract: Methods and apparatus are disclosed for handing over of a high-speed mobile terminal or user equipment from a source network node to a target network node. Reliable methods for measuring the speed of a moving user equipment are disclosed. Parameters used in a handover procedure are also adjusted in accordance with the speed of the user equipment. For handing over a high-speed user equipment, the present application discloses that the source network node can coordinate with the target network node and other candidate network nodes in transmitting a handover command to prevent handover failures.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: February 21, 2017
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Xiaoming Lai, Xixian Chen, Weigang Li
  • Publication number: 20170034758
    Abstract: Methods and apparatus are disclosed for handing over of a high-speed mobile terminal or user equipment from a source network node to a target network node. Reliable methods for measuring the speed of a moving user equipment are disclosed. Parameters used in a handover procedure are also adjusted in accordance with the speed of the user equipment. For handing over a high-speed user equipment, the present application discloses that the source network node can coordinate with the target network node and other candidate network nodes in transmitting a handover command to prevent handover failures.
    Type: Application
    Filed: October 14, 2016
    Publication date: February 2, 2017
    Inventors: Xiaoming Lai, Xixian Chen, Weigang Li
  • Patent number: 9496939
    Abstract: A node (28) of a radio access network (20) communicates over a radio interface (32) with a wireless terminal (30). The node (28) comprises a transmitter (34) and a controller (40). The transmitter (34) selectively operates in plural multiple input multiple output (MIMO) modes for downlink transmission over the radio interface (32). The controller (40) uses both a terminal speed value and a throughput value to make a determination when to switch between the plural multiple input multiple output (MIMO) modes for communicating with the wireless terminal. The plural MIMO modes comprise a first mode and a second mode. In the first mode open loop MIMO operates with cyclical diversity delay. In the second mode open loop MIMO operates without cyclical diversity delay. Although operating in open loop MIMO, advantages such as those of closed loop MIMO are realized.
    Type: Grant
    Filed: May 18, 2015
    Date of Patent: November 15, 2016
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Xixian Chen, Peter Deane, Xiaoming Lai
  • Publication number: 20160277172
    Abstract: In one embodiment, a method of operating a radio access node is provided. The method comprises determining whether support from a secondary cell is required for a wireless device to communicate with the radio access node, and, in response to determining that support from the secondary cell is required, calculating a modified channel condition outer-loop value for the secondary cell; and using the modified channel condition outer-loop value in an initial activation decision step for the secondary cell, The initial activation decision step may comprise activating the secondary cell in response to determining that the sum of a device reported channel condition value and the modified channel condition outer-loop value is above an activation threshold. Corresponding devices, computer programs and radio access nodes adapted to carry out the methods provided are also disclosed.
    Type: Application
    Filed: March 16, 2015
    Publication date: September 22, 2016
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Ping YU, Peter HAZY, Xixian CHEN, James Jianfeng WENG, Ying SHAO, Patrick LIE CHIN CHEONG, Guoqiang LU, Hong YU
  • Publication number: 20160278102
    Abstract: According to certain embodiments, methods and systems for toggling transmission parameters in a heterogeneous network to achieve a target block error rate by a network node may include obtaining a signal-to-noise ratio (SINR) estimate from channel quality information for a downlink between a network node and a wireless device. For each of a first code word and a second code word to be transmitted on the downlink, a block error rate estimate may be obtained based on the SINR estimate. The network node may then determine at least one expected SINR for the first code word and the second code word. The at least one expected SINR may be determined as a function of the SINR estimate and the block error rate estimate. Based on the at least one expected SINR for the first code word and the second code word, a modulation and coding scheme (MCS) for obtaining a target block error rate may be selected.
    Type: Application
    Filed: October 29, 2014
    Publication date: September 22, 2016
    Inventors: Chandra Sekhar Bontu, Jianguo Long, Xixian Chen
  • Publication number: 20160261365
    Abstract: Systems and methods for control signal outer-loop adjustment are disclosed. In some embodiments, a method of operation of a network node in a cellular communications network is provided. The method includes transmitting a control signal and a data signal to a wireless device. The method also includes detecting an ambiguous state of reception of the control signal by the wireless device based on a feedback of reception of the data signal. The method also includes, in response to detecting the ambiguous state of reception, updating a link adaptation (LA) parameter used to choose a coding scheme and power level for transmission of information in the control signal. By updating the LA parameter in response to detecting the ambiguous state of reception, the network node may provide improved performance.
    Type: Application
    Filed: November 14, 2014
    Publication date: September 8, 2016
    Inventors: Xixian Chen, James Jianfeng Weng, Ahmed Nouah, Ying Shao
  • Publication number: 20160241615
    Abstract: According to certain embodiments, methods and systems for providing broadcast multicast service include transmitting, by a network node, a first transmission of multicast content data to wireless devices at a first quality of service level and a second transmission of multicast content data to the wireless devices at a second quality of service level. The second quality of service level may be of a higher quality of service than the first quality of service. Feedback may be received from at least one wireless device in the broadcast service area. In response to the feedback from the wireless devices, one or more transmission parameters associated with a subsequent transmission of the multicast content data may be adjusted.
    Type: Application
    Filed: October 20, 2014
    Publication date: August 18, 2016
    Inventors: Xixian Chen, Xiaoming LAI, Weigang LI
  • Patent number: 9380576
    Abstract: An apparatus for allocating radio resources shared among a plurality of network operators is provided. Each network operator has at least one scheduling entity, SE, and a respective resource allocation, RA, probability for being selected for radio resource allocation during a transmission time interval, TTI. The apparatus includes a processor and a memory. The memory contains instructions executable by the processor that are configured to cause the apparatus, within a TTI, to select a network operator of the plurality of network operators for resource allocation within the TTI based at least in part on the RA probability of the network operator, allocate radio resources to an SE of the selected network operator within the TTI and update the RA probability of selecting each of the plurality of network operators for a next selection of resource allocation.
    Type: Grant
    Filed: May 1, 2014
    Date of Patent: June 28, 2016
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Weigang Li, Xiaoming Lai, Xixian Chen
  • Patent number: 9379842
    Abstract: A method and base station for adjusting outer-loop adjustment values used for link adaptation in a wireless communication network is provided. A modulation of a user equipment is determined and a success or failure of a Transport Block (TB) based on a TB feedback message is determined. Based on the TB feedback, one of an acknowledgement counter and a non-acknowledgement counter is incremented corresponding to the determined modulation. An upward step size for the determined modulation is updated based on the respective acknowledgement counter and the non-acknowledgement counter to affect link adaption.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: June 28, 2016
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Xixian Chen, Hong Ren, Edward Mah, Shiguang Guo, Ping Yu, Guoqiang Lu
  • Publication number: 20160157294
    Abstract: A mobile phone network node may determine traffic load associated with a mobile phone network and initiate discontinuous transmission at a frame level, based at least in part upon, determining that the traffic load is less than a first threshold. The mobile phone network node may further initiate discontinuous transmission at a subframe level, based at least in part upon, determining that the traffic load is greater than the first threshold and less than a second threshold and initiate discontinuous transmission at a symbol level, based at least in part upon, determining that the traffic load is greater than the second threshold.
    Type: Application
    Filed: December 3, 2015
    Publication date: June 2, 2016
    Inventors: Weigang Li, Xiaoming Lai, Xixian Chen
  • Patent number: 9246651
    Abstract: A method and base station for outerloop adjustment for link adaptation of a physical downlink control channel, PDCCH, in a communication network to determine a control channel element, CCE, aggregation level of a downlink assignment downlink control information, DCI, and a CCE aggregation level of an uplink grant DCI is provided. A downlink data packet feedback corresponding to the downlink assignment is received. A status of the downlink data packet feedback is determined. An uplink data packet corresponding to the uplink grant is received and a status thereof is determined. An outerloop downlink adjustment and outerloop uplink adjustment are updated based on at least one of the status of the downlink data packet feedback corresponding to the downlink assignment and status of the uplink data packet corresponding to the uplink grant. An outerloop uplink adjustment is determined as a sum of the outerloop downlink adjustment and an offset adjustment.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: January 26, 2016
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Shiguang Guo, Guoqiang Lu, Xixian Chen, Ping Yu, Hong Ren, Ahmed Nouah
  • Patent number: 9215744
    Abstract: A mobile phone network node may determine traffic load associated with a mobile phone network and initiate discontinuous transmission at a frame level, based at least in part upon, determining that the traffic load is less than a first threshold. The mobile phone network node may further initiate discontinuous transmission at a subframe level, based at least in part upon, determining that the traffic load is greater than the first threshold and less than a second threshold and initiate discontinuous transmission at a symbol level, based at least in part upon, determining that the traffic load is greater than the second threshold.
    Type: Grant
    Filed: May 15, 2014
    Date of Patent: December 15, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Weigang Li, Xiaoming Lai, Xixian Chen
  • Patent number: 9203590
    Abstract: Methods and apparatus are disclosed for a generalized outer loop link adaptation procedure. A normal outer-loop control procedure corrects an estimated SINR, which may be inaccurate if the estimate SINR is mapped from a channel quality estimate that does not reflect the true radio link condition. A normal outer control procedure functions properly only when a normal Modulation and Coding Scheme (MCS) is selected. A normal MCS is the highest Modulation and Coding Scheme (MCS) with which the target Block Error Rate (BLER) can be achieved given a certain number of HARQ (Hybrid Automatic Repeat Request) transmissions. The present application discloses a generalized outer loop link adaptation procedure that functions properly whether the selected MCS is normal, aggressive, or conservative.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: December 1, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Hong Ren, Xixian Chen, Peter Hazy
  • Publication number: 20150334771
    Abstract: A mobile phone network node may determine traffic load associated with a mobile phone network and initiate discontinuous transmission at a frame level, based at least in part upon, determining that the traffic load is less than a first threshold. The mobile phone network node may further initiate discontinuous transmission at a subframe level, based at least in part upon, determining that the traffic load is greater than the first threshold and less than a second threshold and initiate discontinuous transmission at a symbol level, based at least in part upon, determining that the traffic load is greater than the second threshold.
    Type: Application
    Filed: May 15, 2014
    Publication date: November 19, 2015
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Weigang Li, Xiaoming Lai, Xixian Chen
  • Publication number: 20150319741
    Abstract: An apparatus for allocating radio resources shared among a plurality of network operators is provided. Each network operator has at least one scheduling entity, SE, and a respective resource allocation, RA, probability for being selected for radio resource allocation during a transmission time interval, TTI. The apparatus includes a processor and a memory. The memory contains instructions executable by the processor that are configured to cause the apparatus, within a TTI, to select a network operator of the plurality of network operators for resource allocation within the TTI based at least in part on the RA probability of the network operator, allocate radio resources to an SE of the selected network operator within the TTI and update the RA probability of selecting each of the plurality of network operators for a next selection of resource allocation.
    Type: Application
    Filed: May 1, 2014
    Publication date: November 5, 2015
    Inventors: Weigang Li, Xiaoming Lai, Xixian Chen
  • Patent number: 9166745
    Abstract: A method and apparatus is provided for assigning resources for an acknowledgement channel, such as the PHICH in LTE systems. Acknowledgement channels for the mobile terminals are assigned to channel groups based on a predetermined assignment criteria. All acknowledgment channels in the same channel group receive acknowledgements on the same downlink resources (e.g., resource elements in OFDM system). A required transmit energy for each channel is determined. If the total required transmit energy for all channels exceeds an available transmit power, the allocated transmit energy for each channel is either scaled down so that the total actual transmit power for all acknowledgment channels is equal to the available transmit power, or some acknowledgment channels are not transmitted.
    Type: Grant
    Filed: December 31, 2010
    Date of Patent: October 20, 2015
    Assignee: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Hong Ren, Xixian Chen
  • Patent number: 9131515
    Abstract: A wireless receiver receives reference signals over a wireless link. The wireless receiver calculates a selection indication based on the received reference signals, and the wireless receiver selects from among plural channel estimation techniques based on the selection indication, where the selected channel estimation technique is usable to perform channel estimation of the wireless link.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: September 8, 2015
    Assignee: BlackBerry Limited
    Inventors: Jiandong Zhuang, Xixian Chen, Edward Ken Kiu Mah
  • Publication number: 20150249490
    Abstract: A node (28) of a radio access network (20) communicates over a radio interface (32) with a wireless terminal (30). The node (28) comprises a transmitter (34) and a controller (40). The transmitter (34) selectively operates in plural multiple input multiple output (MIMO) modes for downlink transmission over the radio interface (32). The controller (40) uses both a terminal speed value and a throughput value to make a determination when to switch between the plural multiple input multiple output (MIMO) modes for communicating with the wireless terminal. The plural MIMO modes comprise a first mode and a second mode. In the first mode open loop MIMO operates with cyclical diversity delay. In the second mode open loop MIMO operates without cyclical diversity delay. Although operating in open loop MIMO, advantages such as those of closed loop MIMO are realized.
    Type: Application
    Filed: May 18, 2015
    Publication date: September 3, 2015
    Inventors: Xixian Chen, Peter Deane, Xiaoming Lai
  • Publication number: 20150172022
    Abstract: A method and base station for outerloop adjustment for link adaptation of a physical downlink control channel, PDCCH, in a communication network to determine a control channel element, CCE, aggregation level of a downlink assignment downlink control information, DCI, and a CCE aggregation level of an uplink grant DCI is provided. A downlink data packet feedback corresponding to the downlink assignment is received. A status of the downlink data packet feedback is determined. An uplink data packet corresponding to the uplink grant is received and a status thereof is determined. An outerloop downlink adjustment and outerloop uplink adjustment are updated based on at least one of the status of the downlink data packet feedback corresponding to the downlink assignment and status of the uplink data packet corresponding to the uplink grant. An outerloop uplink adjustment is determined as a sum of the outerloop downlink adjustment and an offset adjustment.
    Type: Application
    Filed: December 13, 2013
    Publication date: June 18, 2015
    Inventors: Shiguang GUO, Guoqiang LU, Xixian CHEN, Ping YU, Hong REN, Ahmed NOUAH
  • Patent number: 9036608
    Abstract: A node (28) of a radio access network (20) communicates over a radio interface (32) with a wireless terminal (30). The node (28) comprises a transmitter (34) and a controller (40). The transmitter (34) selectively operates in plural multiple input multiple output (MIMO) modes for downlink transmission over the radio interface (32). The controller (40) uses both a terminal speed value and a throughput value to make a determination when to switch between the plural multiple input multiple output (MIMO) modes for communicating with the wireless terminal. The plural MIMO modes comprise a first mode and a second mode. In the first mode open loop MIMO operates with cyclical diversity delay. In the second mode open loop MIMO operates without cyclical diversity delay. Although operating in open loop MIMO, advantages such as those of closed loop MIMO are realized.
    Type: Grant
    Filed: November 9, 2012
    Date of Patent: May 19, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Xixian Chen, Peter Deane, Xiaoming Lai