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: 8520718
    Abstract: Certain aspects of the present disclosure relate to a method for uplink wireless communications. In one aspect, a diversity scheme may be selectively and adaptively applied to an uplink transmission based on a determination of whether the uplink transmission comprises one or more orphan symbols. According to an aspect, the determination is made based on whether a sounding reference signal is received in the uplink subframe and whether the uplink subframe is configured with a normal or extended cyclic prefix.
    Type: Grant
    Filed: June 17, 2010
    Date of Patent: August 27, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Xiliang Luo, Juan Montojo
  • Patent number: 8520658
    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: June 28, 2011
    Date of Patent: August 27, 2013
    Assignee: Qualcomm Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen, Juan Montojo
  • Patent number: 8503572
    Abstract: Systems and methodologies are described that facilitate performing antenna virtualization in a wireless communication environment. A set of physical transmit antennas can be partitioned into a plurality of groups of physical transmit antennas. Further, a precoding vector for a particular group of physical transmit antennas from the plurality of groups of physical transmit antennas can be formulated. Moreover, the particular group of physical transmit antennas can form a particular virtual antenna. By way of another example, a disparate precoding vector for a disparate group of physical transmit antennas from the plurality of groups of physical transmit antennas can be formulated, and the disparate group of physical transmit antennas can form a disparate virtual antenna. The precoding vector can be applied to a signal for transmission over the particular virtual antenna, and the disparate precoding vector can be applied to a disparate signal for transmission over the disparate virtual antenna.
    Type: Grant
    Filed: February 1, 2010
    Date of Patent: August 6, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Amir Farajidana, Xiaoxia Zhang, Juan Montojo
  • Publication number: 20130114441
    Abstract: A delayed channel estimation is a channel state information (CSI) reference subframe having an index (NCSI—ref) belonging to NCSI—ref=N?4?k, where N is the subframe index on which the CSI is to be transmitted on an uplink, and k is the smallest value of k>=0, such that N?4?k belongs to a given configuration set. When k is too large, the selected CSI reference subframe is too outdated to produce accurate CSI. An undelayed channel estimation is a CSI reference subframe having an index (NCSI—ref) belonging to NCSI—ref=N?4. When the CSI reference subframe N?4 does not belong to the given subframe restriction subset, the selected channel estimate may be too noisy to produce accurate CSI. A method for CSI computation for enhanced inter-cell interference coordination (eICIC) selects between a delayed channel estimation and an undelayed channel estimation for computing CSI, for example, based on a signal metric. The CSI is computed with a selected channel estimation.
    Type: Application
    Filed: September 10, 2012
    Publication date: May 9, 2013
    Applicant: QUALCOMM INCORPORATED
    Inventors: Taesang Yoo, Xiliang Luo, Tao Luo, Yongbin Wei
  • Patent number: 8428521
    Abstract: In a wireless communication network that performs Multiple Input Multiple Output (MIMO) communication, uplink power control signals are provided to a user equipment (UE) via a base station signaled power allocation scheme responsive to a determination of whether or not the uplink transmission is in a interference limited condition relative to a neighboring cell.
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: April 23, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Juan Montojo
  • Publication number: 20120294204
    Abstract: A method, apparatus, and computer program product for wireless communication are provided to receive a downlink grant including a transmission power control (TPC) command and a downlink assignment index (DAI) for an uplink subframe, determine that a value for at least one of the TPC commands is an ACK/NACK resource indicator for an uplink control channel resource based on a value of the DAI, and transmit one or more ACK/NACK bits using the uplink control channel resource. In another example, an eNB may be equipped to transmit a downlink grant including TPC command and DAI for an uplink subframe, wherein the DAI is greater than 1 and the TPC command is replaced with an ACK/NACK resource indicator, and receive a signal including uplink control channel information, where ACK/NACK feedback for one or more downlink subframes associated with the uplink subframe are included in a resource indicated by the resource indicator.
    Type: Application
    Filed: November 14, 2011
    Publication date: November 22, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Wanshi Chen, Xiliang Luo, Juan Montojo
  • Publication number: 20120287828
    Abstract: Bits for acknowledgement (ACK) and/or negative acknowledgement (NAK) may be allocated based on whether a special subframe configuration in a TDD configuration permits downlink transmission. For carrier aggregation, ACK/NAK bits may be allocated only to special subframes in component carriers (CCs) which permit downlink transmission. Also, for example, ACK/NAK bits may be allocated to all CC special subframes if a single CC is configured to allow downlink transmission on one of its special subframes. ACK/NAK bits may also be allocated to all special subframes.
    Type: Application
    Filed: November 9, 2011
    Publication date: November 15, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Wanshi Chen, Juan Montojo, Xiliang Luo
  • Publication number: 20120263124
    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: Application
    Filed: October 7, 2011
    Publication date: October 18, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Peter Gaal, Wanshi Chen, Xiliang Luo, Juan Montojo
  • Publication number: 20120263121
    Abstract: A method of wireless communication includes receiving an upper layer configuration of multiple sets of ACK/NAK resources for uplink transmission. The receives resources correspond to at least one secondary downlink component carrier in a multicarrier configuration. The method also includes receiving a physical layer indicator of ACK/NAK resources in the sets.
    Type: Application
    Filed: October 3, 2011
    Publication date: October 18, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Wanshi Chen, Peter Gaal, Xiliang Luo, Juan Montojo
  • Publication number: 20120236741
    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: February 13, 2012
    Publication date: September 20, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Hao Xu, Xiliang Luo, Xiaoxia Zhang, Peter Gaal, Tingfang Ji, Juan Montojo
  • Publication number: 20120236771
    Abstract: In a multi-carrier wireless communication system, component carrier configuration and reconfiguration uses uplink control channel resource mapping with fallback configurations to maintain alignment between a user equipment and a base station during reconfiguration.
    Type: Application
    Filed: September 14, 2011
    Publication date: September 20, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen
  • Publication number: 20120213109
    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.
    Type: Application
    Filed: February 21, 2012
    Publication date: August 23, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Hao Xu, Xiliang Luo, Peter Gaal, Tingfang Ji, Kapil Bhattad
  • Publication number: 20120208541
    Abstract: Wireless networks may include remote radio heads (RRHs) for extending the coverage of a macro cell. The macro cell may be connected to the RRHs, for example, by optical fiber, and there may be negligible latency between the macro cell and the RRHs. As a user equipment (UE) moves within the macro cell, or between other macro cells, mobility procedures followed by the UE may vary based on the release of the UE (e.g., Rel-8/9, Rel-10, or Rel-11 and beyond). The macro cell may handle all the scheduling within the cell, for itself and the RRHs.
    Type: Application
    Filed: February 11, 2012
    Publication date: August 16, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Hao Xu, Wanshi Chen, Tingfang Ji, Peter Gaal, Juan Montojo
  • Publication number: 20120163159
    Abstract: A method for transmitting an acknowledgement/negative acknowledgement is described. Cell-specific symbol-level cyclic shift hopping is applied to data single-carrier frequency division multiplexing symbols of the acknowledgement/negative acknowledgement. A discrete Fourier transform is applied to the data single-carrier frequency division multiplexing symbols. Cell-specific symbol-level phase hopping is applied to the data single-carrier frequency division multiplexing symbols. The data single-carrier frequency division multiplexing symbols are transmitted in a slot.
    Type: Application
    Filed: December 21, 2011
    Publication date: June 28, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen, Hao Xu, Tao Luo, Kapil Bhattad, Xiaoxia Zhang
  • Publication number: 20120134305
    Abstract: Methods, systems, devices, and computer program products are described which facilitate the transmission and reception of acknowledgment/negative acknowledgment (ACK/NACK) feedback associated with downlink data transmissions in a multi-carrier wireless communication system. Scheduling request resources may be utilized to enable the transmission of ACK/NACK feedback for the multiple component carriers when a positive scheduling request is present and the techniques described may be utilized to improve the efficiency of control channel signaling in different system configurations.
    Type: Application
    Filed: October 28, 2011
    Publication date: May 31, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Jelena M. Damnjanovic, Wanshi Chen, Xiliang Luo, Juan Montojo
  • Publication number: 20120120882
    Abstract: Certain aspects of the present disclosure provide techniques for determining resources for transmission of acknowledgement messages to a user equipment (UE). The techniques involve receiving a plurality of codewords from the UE via an uplink component carrier, and determining at least first and second index pairs identifying resources of a downlink channel to be used for transmitting acknowledgement messages for the received codewords. The first index pair is determined based on a first set of parameters, and the second index pair is determined based on the first set of parameters and a second set of one or more parameters. At least one of the parameters in the second set is a fixed value.
    Type: Application
    Filed: May 12, 2011
    Publication date: May 17, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen, Tao Luo, Juan Montojo
  • Publication number: 20120114065
    Abstract: A method of wireless communication is disclosed which includes acquiring a first set of precoding matrices for a set of frequency bands and generating a second set of precoding matrices for the set of frequency bands based on the first set of precoding matrices. The second set of precoding matrices enables a transmission that satisfies a cubic metric criteria in multiple-in multiple-out communication mode in the uplink. In some designs, generating the second set of precoding matrices can be based on restricting the first set of precoding matrices for a set of frequency bands and transmission rank, rotating the first set of precoding matrices based for a predetermined transmission rank, or a combination thereof.
    Type: Application
    Filed: May 11, 2011
    Publication date: May 10, 2012
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Peter Gaal, Juan Montojo
  • Publication number: 20120115534
    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: Application
    Filed: November 3, 2011
    Publication date: May 10, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: XILIANG LUO, Peter Gaal, Hao Xu, Wanshi Chen, Tao Luo, Juan Montojo, Xiaoxia Zhang
  • Publication number: 20120113898
    Abstract: Methods and apparatuses are provided that include using orthogonal precoding vectors to precode signals for transmission in a given subframe. Transmissions in a first slot of the subframe can be precoded with a first precoding vector, and transmissions in a second slot of the subframe can be precoded with a second precoding vector, which can be orthogonal to the first precoding vector. The precoding vectors can be selected using precoding vector switching or a similar mechanism. Thus, diversity is provided for transmissions within a given subframe to improve reliability of receiving the transmissions. In addition, other precoding vectors can be used to precode signals for transmissions in a subsequent subframe.
    Type: Application
    Filed: October 27, 2011
    Publication date: May 10, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen, Juan Montojo
  • Publication number: 20120114014
    Abstract: Methods and apparatuses are provided that include providing transmit diversity for data channel transmissions. Different precoding vectors can be used over different slots of a given subframes to precode corresponding signals. The precoding vectors, in one example, can be orthogonal. In addition, using the different precoding vectors can be determined based on a user equipment receiving an indicator from a base station receiving the data channel transmissions of whether to use frequency hopping over the slots. Moreover, precoding vectors used to precode data channel transmissions can additionally or alternatively vary across subframes.
    Type: Application
    Filed: October 26, 2011
    Publication date: May 10, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Peter Gaal, Wanshi Chen, Xiliang Luo, Juan Montojo