Patents by Inventor Xiliang Luo

Xiliang Luo 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: 10680771
    Abstract: Techniques are provided for combining different types of reference signals. A wireless communications network may be configured to allow a user equipment (UE) to combine multiple demodulation reference signals (DM-RSs) to support demodulation of a physical downlink shared channel (PDSCH), and/or other downlink transmissions, transmitted from a base station to the UE. The base station may provide explicit signaling that reference signals transmitted in two or more transmission time intervals may be combined, or a determination that reference signals transmitted in two or more transmission time intervals may be combined may be made implicitly based on system configuration and previous transmissions. Based on the explicit signaling and/or implicit determination, a UE may combine reference signals included in each of two or more reference signals for use in demodulation of downlink transmissions.
    Type: Grant
    Filed: July 13, 2015
    Date of Patent: June 9, 2020
    Assignee: QUALCOMM Incorporated
    Inventors: Taesang Yoo, Xiliang Luo, Peter Gaal, Tao Luo, Durga Prasad Malladi, Yongbin Wei, Wanshi Chen, Hao Xu, Aleksandar Damnjanovic, Arumugam Chendamarai Kannan
  • Publication number: 20200007279
    Abstract: Systems and methods are disclosed for control-data multiplexing as well as control-data decoupling. In one embodiment, a semi-static approach is disclosed, wherein the upper layer(s) are configured such that each user equipment uses either control-data multiplexing or control-data decoupling. Additionally or alternatively, a dynamic approach is disclosed, in which one bit is added to the DCI format which indicates whether the UE is using control-data multiplexing or control-data coupling.
    Type: Application
    Filed: June 28, 2019
    Publication date: January 2, 2020
    Inventors: Wanshi CHEN, Juan MONTOJO, Xiliang LUO, Xiaoxia ZHANG
  • Patent number: 10420082
    Abstract: Techniques for sending control information relating to multiple downlink carriers and data on a single uplink carrier are described. A user equipment (UE) may be scheduled to transmit on a designated uplink carrier. The UE can multiplex control information for multiple downlink carriers with data for transmission on the uplink carrier in a same subframe. Multiplexing may be performed according to a type of the control information and/or an ordering, priority, or association of the downlink carriers. The UE can selectively encode the control information separately for each downlink carrier and/or jointly across downlink carriers. The control information may be mapped to a single layer or multiple layers of a data channel. The UE may send the multiplexed control information and data on the data channel in the subframe while maintaining a single-carrier waveform.
    Type: Grant
    Filed: June 18, 2015
    Date of Patent: September 17, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Tao Luo, Peter Gaal, Xiaoxia Zhang, Hao Xu, Juan Montojo
  • Patent number: 10341914
    Abstract: Antenna selection and reassignment in multiple radio access technology (RAT) communication systems with unlicensed spectrum is disclosed. Aspects include a user equipment (UE) monitoring for a channel reserving signal in each frame from multiple transmission sources. If no channel reserving signal is detected, then the UE reassigns one or more of the antennas previously assigned to the transmission sources with no activity detected. Additional aspects include base stations that determine a clear channel assessment (CCA) status for each of unlicensed carrier designated for transmission to a UE. The base station will transmit a receive antenna usage adjustment signal to the UE based on the determined CCA status.
    Type: Grant
    Filed: February 18, 2015
    Date of Patent: July 2, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Durga Prasad Malladi, Xiliang Luo, Yongbin Wei
  • Publication number: 20190124608
    Abstract: Certain aspects of the present disclosure relate to techniques for power control and user multiplexing for coordinated multi-point (CoMP) transmission and reception in heterogeneous networks (HetNet).
    Type: Application
    Filed: November 21, 2018
    Publication date: April 25, 2019
    Inventors: Hao XU, Xiliang LUO, Xiaoxia ZHANG, Peter GAAL, Tingfang JI, Juan MONTOJO
  • Patent number: 10187859
    Abstract: Certain aspects of the present disclosure relate to techniques for power control and user multiplexing for coordinated multi-point (CoMP) transmission and reception in heterogeneous networks (HetNet).
    Type: Grant
    Filed: February 13, 2012
    Date of Patent: January 22, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Hao Xu, Xiliang Luo, Xiaoxia Zhang, Peter Gaal, Tingfang Ji, Juan Montojo
  • Patent number: 10033497
    Abstract: A wireless communication method includes configuring a plurality of common sounding reference signal (SRS) subframes shared with one or more cooperating cells and providing an SRS configuration parameter to facilitate an orthogonal SRS transmission over at least one of the plurality of common SRS subframes.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: July 24, 2018
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Peter Gaal, Juan Montojo
  • Patent number: 9860881
    Abstract: A wireless communication method includes allocating physical uplink control channel (PUCCH) data in first slot to a first orthogonal cover code (OCC). The method also includes allocating PUCCH data in a second slot of the same subframe to a different orthogonal cover code (OCC). Another method includes mapping PUCCH resources to physical resource blocks based on a user equipment (UE) specific signaling parameter (e.g., a resource index) and a number of symbols in a slot of a subframe.
    Type: Grant
    Filed: June 26, 2015
    Date of Patent: January 2, 2018
    Assignee: QUALCOMM Incorporated
    Inventors: Peter Gaal, Wanshi Chen, Xiliang Luo, Juan Montojo
  • Patent number: 9820245
    Abstract: Methods and apparatus for selecting samples for secondary synchronization signal (SSS) detection are described. Several alternatives are provided for efficient cell identifier detection. In a first alternative, multiple bursts of a signal received from a cell are sampled with non-uniform spacing between sampling intervals to determine a sequence for cell identification. In a second alternative, samples of a first and a second signal received from a stronger cell are cancelled, and a sequence for detecting a weaker cell is determined by reducing effects of the samples of a third signal received from the weaker cell which do not overlap with the primary synchronization signal (PSS) or SSS of the stronger cell. In a third alternative, a sequence for detecting a weaker cell is determined by reducing effects of any sampled bursts that correspond to a high transmission power portion of a signal from a stronger cell.
    Type: Grant
    Filed: February 17, 2014
    Date of Patent: November 14, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Kapil Bhattad, Xiaoxia Zhang, Taesang Yoo, Xiliang Luo, Ke Liu
  • Patent number: 9735932
    Abstract: A precoding scheme to accommodate user equipment (UEs) having higher Doppler speeds. In such transmission schemes, a different precoding matrix is applied to each orthogonal frequency division multiplex (OFDM) symbol in the transmission stream. Additionally, a downlink control message format is defined to handle assignment of multiple different transmission schemes using the same message format. The downlink control message format includes a control element in one of the message fields along with a set of parameters specifically applicable to the assigned transmission scheme. Based on the value of this control element, the UE sets the specific transmission scheme and determines a set of interpretation rules uniquely associated with that transmission scheme. Using the interpretation rules, the UE is able to read the set of parameters as applied to the selected transmission scheme.
    Type: Grant
    Filed: March 18, 2015
    Date of Patent: August 15, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Juan Montojo, Wanshi Chen, Hao Xu, Tao Luo, Kapil Bhattad
  • Patent number: 9730193
    Abstract: Provided is a method for wireless communication which includes transmitting codewords according to an initial transmission rank, receiving downlink transmissions indicating at least one of the codewords to be retransmitted, constructing a demodulation reference signal (DM-RS) to be sent with the at least one codeword to be retransmitted, and retransmitting the at least one codeword with the DM-RS according to a retransmission rank. The downlink transmissions may include one or more physical hybrid automatic retransmission request indicator channels and the DM-RS may be constructed based at least in part on information in the downlink transmissions.
    Type: Grant
    Filed: August 26, 2013
    Date of Patent: August 8, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen, Juan Montojo
  • Patent number: 9698954
    Abstract: Methods and apparatuses are provided for determining cyclic shift (CS) values and/or orthogonal cover codes (OCC) for a plurality of demodulation reference signals (DM-RS) transmitted over multiple layers in multiple-input multiple-output (MIMO) communications. A CS index can be received from a base station in downlink control information (DCI) or similar signaling. Based at least in part on the CS index, CS values for the plurality of DM-RS can be determined. In addition, OCC can be explicitly signaled or similarly determined from the CS index and/or a configured CS value received from a higher layer. In addition, controlling assignment of CS indices and/or OCC can facilitate providing orthogonality for communications from paired devices in multiuser MIMO.
    Type: Grant
    Filed: February 8, 2016
    Date of Patent: July 4, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Xiaoxia Zhang, Peter Gaal, Juan Montojo
  • Patent number: 9686761
    Abstract: Methods and apparatus for selecting samples for secondary synchronization signal (SSS) detection are described. Several alternatives are provided for efficient cell identifier detection. In a first alternative, multiple bursts of a signal received from a cell are sampled with non-uniform spacing between sampling intervals to determine a sequence for cell identification. In a second alternative, samples of a first and a second signal received from a stronger cell are cancelled, and a sequence for detecting a weaker cell is determined by reducing effects of the samples of a third signal received from the weaker cell which do not overlap with the primary synchronization signal (PSS) or SSS of the stronger cell. In a third alternative, a sequence for detecting a weaker cell is determined by reducing effects of any sampled bursts that correspond to a high transmission power portion of a signal from a stronger cell.
    Type: Grant
    Filed: February 17, 2014
    Date of Patent: June 20, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Kapil Bhattad, Xiaoxia Zhang, Taesang Yoo, Xiliang Luo, Ke Liu
  • Patent number: 9648625
    Abstract: A system and method for facilitating resource management in OFDM systems is provided. The system permits different and flexible resource cell metric operations levels (e.g. uplink load management, admission control, congestion control, signal handoff control) for different sub-bands. For the uplink load management, there are multiple distinct load operation points (e.g. IoT, RoT) per sub-band group instead of the same operation level across the entire available band. The sub-band groups encompass the entire band. The facilitation system also comprises a variety of transmitting protocols, command increment variable stepsize methods and robust command response methods. The system thus provides more flexible reverse link resource management and more efficient utilization of the bandwidth.
    Type: Grant
    Filed: January 12, 2015
    Date of Patent: May 9, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Wanshi Chen, Xiaoxia Zhang, Durga Prasad Malladi, Xiliang Luo
  • Patent number: 9635624
    Abstract: Certain aspects of the present disclosure relate to techniques that may be used to discover transmission points in heterogeneous networks (HetNet) that involves coordinated multi-point (CoMP) transmission and reception. Certain aspects of the present disclosure provide a method for wireless communications by a user equipment (UE). The method generally includes receiving a configuration indicating distinct resources used by each of a plurality of different transmission points involved in coordinated multipoint (CoMP) operations with the UE for transmitting discovery reference signals (RSs), receiving distinct discovery RSs transmitted from the plurality of different transmission points, and calculating at least one of path loss or reference signal received power (RSRP) estimations for each of the transmission points based on the distinct discovery RSs.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: April 25, 2017
    Assignee: QUALCOMM INCORPORATED
    Inventors: Hao Xu, Xiliang Luo, Peter Gaal, Tingfang Ji, Kapil Bhattad
  • Publication number: 20170104567
    Abstract: A wireless communication method includes configuring a plurality of common sounding reference signal (SRS) subframes shared with one or more cooperating cells and providing an SRS configuration parameter to facilitate an orthogonal SRS transmission over at least one of the plurality of common SRS subframes.
    Type: Application
    Filed: December 22, 2016
    Publication date: April 13, 2017
    Inventors: Xiliang Luo, Wanshi Chen, Peter Gaal, Juan Montojo
  • Patent number: 9622188
    Abstract: System(s) and method(s) are provided for inter-cell power control in the presence of fractional frequency reuse in a wireless communication system. Transmission power control of a terminal, and ensuing inter-cell interference mitigation, is accomplished by receiving load indicators from non-serving sectors, decoding those load indicators corresponding to the non-serving sectors that operate in the same frequency bands as the terminal, and adjusting the transmission power according the states of the decoded load indicators in conjunction with the associated non-serving sectors' forward link signal-to-interference-and-noise ratio at the terminal. The states of the load indicators reflect magnitudes of interference metrics with respect to threshold values. Load indicators can also be conveyed by the non-serving sector to a base station serving the terminal through a backhaul communication, and said base station can schedule an adjusted transmission power for the terminal.
    Type: Grant
    Filed: June 11, 2014
    Date of Patent: April 11, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Durga Prasad Malladi, Xiaoxia Zhang
  • Patent number: 9608780
    Abstract: Techniques for transmitting data with transmit diversity for single-carrier frequency division multiple access (SC-FDMA) are described. In one design, a transmitter (e.g., a UE) may form a first symbol vector including first and second modulation symbol sequences. The transmitter may also form a second symbol vector including third and fourth modulation symbol sequences, which may be generated based on the second and first modulation symbol sequences, respectively. Each symbol vector may further include a cyclic prefix and possibly a cyclic postfix for each modulation symbol sequence. The transmitter may generate a first SC-FDMA symbol based on the first symbol vector and a second SC-FDMA symbol based on the second symbol vector. The transmitter may transmit the first and second SC-FDMA symbols from two transmit antennas in a single SC-FDMA symbol period to achieve transmit diversity.
    Type: Grant
    Filed: September 22, 2009
    Date of Patent: March 28, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Juan Montojo, Wanshi Chen
  • Patent number: 9609559
    Abstract: An idle mode UE can RACH to a cell different from the cell paging the UE. The UE can be allocated additional time to respond to all cells in the neighborhood to identify the cell in which to RACH. Interference cancellation can occur at different rates based on whether the UE is in connected mode or idle mode. The time to respond to the page can be a function of a paging cycle. Additionally, a variable bias may promote early handoff to lower power cells and late handoff to high power cells.
    Type: Grant
    Filed: May 29, 2015
    Date of Patent: March 28, 2017
    Assignee: QUALCOMM INCORPORATED
    Inventors: Kapil Bhattad, Alexei Yurievitch Gorokhov, Tingfang Ji, Ke Liu, Tao Luo, Xiliang Luo
  • Patent number: 9591662
    Abstract: Techniques for acknowledging data transmissions in a multi-carrier wireless communication network are disclosed. In some aspects, a user equipment (UE) receives a data transmission on at least one component carrier (CC) in a plurality of configured CCs. The UE determines acknowledgement/negative acknowledgement (ACK/NACK) information for the data transmission and determines an uplink channel for sending the ACK/NACK information. When the ACK/NACK information is sent on a PUCCH, the UE may perform power control based on which CCs in the plurality of configured CCs data is received. When the ACK/NACK information is sent on a PUSCH, the UE may determine a number of resource elements based on its CC configuration.
    Type: Grant
    Filed: July 6, 2015
    Date of Patent: March 7, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Wanshi Chen, Xiaoxia Zhang, Peter Gaal, Juan Montojo, Xiliang Luo, Tao Luo, Jelena Damnjanovic, Aleksandar Damnjanovic