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: 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: 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: 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: 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
  • Patent number: 9531514
    Abstract: A wireless communication method includes determining whether a wireless device desires dynamic sounding reference signal (SRS) resources and providing, based on the determination, a dynamic SRS resource allocation to the wireless device.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: December 27, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Peter Gaal, Juan Montojo
  • Patent number: 9402273
    Abstract: Methods, systems, and devices are described for a UE to determine a DRX wakeup rule in an eICIC environment. A UE may identify a measurement period associated with reduced interference from one or more cells in a wireless communications network. The cells may be a serving cell or a neighbor cell. The measurement period may be identified based on eICIC data available to the UE. The eICIC data may be sent to the UE by a serving cell and/or determined by the UE. The UE may power up a wireless modem to perform a warm-up measurement of the serving cell during the identified measurement period prior to transitioning the UE to a DRX on state.
    Type: Grant
    Filed: December 23, 2013
    Date of Patent: July 26, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Amir Farajidana, Xiliang Luo, Alexei Yurievitch Gorokhov, Hisham A. Mahmoud, Keith William Saints
  • Patent number: 9398544
    Abstract: Power adjustment in the user equipment (UE) includes adjusting the transmission power level for each of multiple transport blocks based on the spectral efficiency associated with the transport block. The UE receives a scheduled transport format parameter for each of multiple transport blocks to be transmitted. Based on those scheduled transport format parameters, the UE determines a transmit power level adjustment for each transport block. The UE will adjust the power according to the determined transmit power level adjustment and transmit each transport block using the adjusted power level.
    Type: Grant
    Filed: November 3, 2011
    Date of Patent: July 19, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Hao Xu, Wanshi Chen, Tao Luo, Juan Montojo, Xiaoxia Zhang
  • Publication number: 20160156445
    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: Application
    Filed: February 8, 2016
    Publication date: June 2, 2016
    Inventors: Xiliang Luo, Wanshi Chen, Xiaoxia Zhang, Peter Gaal, Juan Montojo
  • Patent number: 9288026
    Abstract: A reference signal is transmitted on multiple non-contiguous clusters of resources. A user equipment (UE) may be scheduled for data transmission on the multiple non-contiguous clusters, and each cluster may cover a set of contiguous subcarriers. The UE may generate the reference signal based on at least one reference signal (RS) sequence using code division multiplexing (CDM) or frequency division multiplexing (FDM). In a design, the UE generates the reference signal with CDM based on a single RS sequence having a length matching the total length of the multiple non-contiguous clusters. In another design, the UE generates the reference signal with CDM based on one RS sequence for each cluster. In yet another design, the UE generates the reference signal with FDM and transmits the reference signal on a subset of all subcarriers for the multiple non-contiguous clusters.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: March 15, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoxia Zhang, Wanshi Chen, Xiliang Luo, Juan Montojo, Peter Gaal
  • Publication number: 20160065341
    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: Application
    Filed: July 13, 2015
    Publication date: March 3, 2016
    Inventors: Taesang Yoo, Xiliang Luo, Peter Gaal, Tao Luo, Durga Prasad Malladi, Yongbin Wei, Wanshi Chen, Hao Xu, Aleksandar Damnjanovic, Arumugam Chendamarai Kannan
  • Patent number: 9258160
    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-RSs 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: January 10, 2011
    Date of Patent: February 9, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Xiaoxia Zhang, Peter Gaal, Juan Montojo
  • Patent number: 9246640
    Abstract: A method of wireless communication comprises receiving a plurality of codewords and transmitting a downlink feedback message by spatially bundling acknowledgments for the received plurality of codewords. In some designs, an accompanying grant message is transmitted with the downlink feedback message.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: January 26, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaoxia Zhang, Wanshi Chen, Xiliang Luo, Tao Luo, Hao Xu, Peter Gaal, Juan Montojo
  • Patent number: 9240864
    Abstract: Certain aspects of the present disclosure relate to methods and apparatus for blind detection of cell-specific reference signals. Methods and apparatus are provided for detecting a cell-specific reference signal (CRS) in an orthogonal frequency division multiplexed (OFDM) symbol by a user equipment (UE). The method generally includes predicting a current channel response of a current OFDM symbol based on a channel response of at least one previous OFDM symbol, estimating a noise power level of the current OFDM symbol, forming a log likelihood ratio (LLR) of two detection hypotheses based on the predicted current channel response and the estimated noise power level, comparing the LLR to a pre-determined threshold, and determining that at least one CRS is present in the current OFDM symbol based on the comparison.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: January 19, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wenshu Zhang, Keith William Saints, Ke Liu, Kapil Bhattad, Alexei Yurievitch Gorokhov
  • Patent number: 9236977
    Abstract: Wireless uplink communication is disclosed which includes dividing information bits into first and second sets of information bits. The first set of information bits is encoded into a first set of coded bits, while the second set of information bits is encoded into a second set of coded bits. The first and second sets of coded bits are rate matched into a defined number of bits generating first and second sets of rate-matched coded bits. The first and second sets of rate-matched coded bits are interleaved using various interleaving methods to generate an interleaved set of coded bits.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: January 12, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Juan Montojo, Wanshi Chen, Peter Gaal