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).

  • Publication number: 20110243012
    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: Application
    Filed: April 1, 2011
    Publication date: October 6, 2011
    Applicant: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Tao Luo, Peter Gaal, Xiaoxia Zhang, Hao Xu, Juan Montojo
  • Publication number: 20110228731
    Abstract: Systems and methods for resource allocation for an uplink control channel for a user equipment (UE) using multiple transmit antennas in a wireless communication network are disclosed. A plurality of orthogonal resources for use by the UE on the uplink control channel is selected. Control information is transmitted from the UE on the uplink control channel on the plurality of orthogonal resources with transmit diversity.
    Type: Application
    Filed: September 24, 2010
    Publication date: September 22, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Wanshi Chen, Jelena M. Damnjanovic, Peter Gaal, Juan Montojo
  • Publication number: 20110207415
    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: Application
    Filed: August 3, 2010
    Publication date: August 25, 2011
    Applicant: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Wanshi Chen, Juan Montojo
  • Publication number: 20110199944
    Abstract: A method and apparatus for facilitating an aperiodic transmission of a sounding reference signal (SRS) are disclosed. Transmission resources are allocated to the aperiodic SRS transmission. A portion of a first downlink control message is modified to produce a second downlink control message, where the first downlink control message does not trigger an aperiodic SRS transmission. The second downlink message is transmitted.
    Type: Application
    Filed: February 9, 2011
    Publication date: August 18, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Wanshi Chen, Peter Gaal, Juan Montojo, Tao Luo, Xiliang Luo
  • Publication number: 20110159914
    Abstract: Methods and apparatus in a wireless communication system are described for receiving and processing transmit power control commands, where, for example, the response to the transmit power control commands is conditionally decoupled from at least one of a transmit bandwidth parameter, a transport format parameter and a power stepsize limit. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the disclosed subject matter. Therefore, it is to be understood that it should not be used to interpret or limit the scope or the meaning of the claims.
    Type: Application
    Filed: December 22, 2010
    Publication date: June 30, 2011
    Applicant: QUALCOMM Incorporated
    Inventors: Wanshi Chen, Peter Gaal, Juan Montojo, Taesang Yoo, Xiliang Luo, Tao Luo, Yongbin Wei, Naga Bhushan
  • Publication number: 20110143696
    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: Application
    Filed: June 17, 2010
    Publication date: June 16, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Tao Luo, Xiliang Luo, Juan Montojo
  • Publication number: 20110141982
    Abstract: Techniques for transmitting a reference signal on multiple non-contiguous clusters of resources are described. 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 an 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: Application
    Filed: June 16, 2010
    Publication date: June 16, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiaoxia Zhang, Wanshi Chen, Xiliang Luo, Juan Montojo, Peter Gaal
  • Publication number: 20110128909
    Abstract: Techniques for efficiently multiplexing a reference signal and data on different sets of subcarriers in the same symbol period are described. In one design, a user equipment (UE) performs a discrete Fourier transform (DFT) on a set of modulation symbols for data to obtain data symbols. The UE also obtains reference symbols generated based on a reference signal sequence corresponding to a cyclic shift of a base sequence. The UE maps the reference symbols to a first set of subcarriers and maps the data symbols to a second set of subcarriers. The UE then generates a transmission symbol based on the mapped reference symbols and the mapped data symbols. The UE may also transmit reference signals and data (i) in multiple symbol periods of a slot or a subframe and/or (ii) from multiple antennas using frequency division multiplexing (FDM) or code division multiplexing (CDM).
    Type: Application
    Filed: October 27, 2010
    Publication date: June 2, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Juan Montojo, Peter Gaal, Ravi Palanki
  • Publication number: 20110110455
    Abstract: Certain aspects of the present disclosure relate to a technique for signaling rank and precoding indications in uplink and downlink MIMO operations using codebook and non-codebook based precoding.
    Type: Application
    Filed: April 22, 2010
    Publication date: May 12, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Peter Gaal, Xiaoxia Zhang, Wanshi Chen, Xiliang Luo, Juan Montojo
  • Publication number: 20110103510
    Abstract: Certain aspects of the present disclosure relate to a technique for signaling rank and precoding indications in uplink and downlink MIMO operations using codebook and non-codebook based precoding.
    Type: Application
    Filed: April 22, 2010
    Publication date: May 5, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Peter Gaal, Xiaoxia Zhang, Wanshi Chen, Xiliang Luo, Juan Montojo
  • Publication number: 20110105137
    Abstract: Certain aspects of the present disclosure relate to a technique for signaling rank and precoding indications in uplink and downlink MIMO operations using codebook and non-codebook based precoding.
    Type: Application
    Filed: April 22, 2010
    Publication date: May 5, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Peter Gaal, Xiaoxia Zhang, Wanshi Chen, Xiliang Luo, Juan Montojo
  • Publication number: 20110096657
    Abstract: Methods, devices and computer program products are provided to improve uplink communications in a wireless communication system. Reference symbols in an uplink transmission radio subframe are time-frequency multiplexed with additional data symbols. The multiplexed data symbols are transmitted in an uplink transmission to another device within the wireless communication network along with non-multiplexed data symbols. The multiplexing operations enable the transmission of additional data symbols without increasing the overhead associated with the transmission of symbols in the radio subframe.
    Type: Application
    Filed: October 21, 2010
    Publication date: April 28, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Peter Gaal, Juan Montojo
  • Patent number: 7864880
    Abstract: Techniques are described that provide inter-symbol interference—(ISI) and multi-user interference—(MUI) resilient blind timing synchronization and low complexity demodulation in wireless communication systems. A nonzero mean symbol is transmitted with a predetermined period in a stream of zero mean symbols during a synchronization phase. Only zero mean symbols are transmitted outside of the synchronization phase. Blind or non-data aided synchronization is performed at the receiver while bypassing channel estimation. The techniques enable timing synchronization via energy detection and low-complexity demodulation by matching the received waveform to a synchronized aggregate template (SAT). The SAT is recovered by averaging samples of the received waveform during the synchronization phase.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: January 4, 2011
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Xiliang Luo
  • Publication number: 20100234061
    Abstract: Methods, systems, apparatus and computer program products are provided to facilitate power control in wireless communication systems. A cell that is experiencing excessive interference conditions may generate an over-the-air overload indicator indicative of interference conditions at the cell. The over-the-air overload indicator is received by one or more user equipment in a neighboring cell. In response, the user equipment determines adjustments to its transmit power that reduce and/or eliminate the interference. This determination may be carried out by the user equipment, by the serving base station, or through cooperation between the user equipment and the serving base station. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the disclosed subject matter. Therefore, it is to be understood that it should not be used to interpret or limit the scope or the meaning of the claims.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 16, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Aamod D. Khandekar, Ravi Palanki, Mohammad J. Borran, Kapil Bhattad, Xiliang Luo
  • Publication number: 20100215007
    Abstract: Techniques for performing channel interleaving to achieve similar SINRs for multiple code blocks are described. In one design, a transmitter station (e.g., a base station or a UE) determines a plurality of resource groups assigned for data transmission. Each resource group includes a plurality of resource elements formed by a cluster of subcarriers in a time interval. The transmitter station partitions a transport block into a plurality of code blocks, processes each code block to obtain data symbols for that code block, and maps the data symbols for each code block to at least one resource element in each of the plurality of resource groups. The transmitter station transmits the mapped data symbols for the plurality of code blocks to a receiver station. In one design, the transmitter station receives an ACK or a NACK for the transport block and retransmits all code blocks if a NACK is received.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 26, 2010
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiaoxia Zhang, Juan Montojo, Peter Gaal, Wanshi Chen, Xiliang Luo
  • Publication number: 20100214938
    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: February 9, 2010
    Publication date: August 26, 2010
    Applicant: QUALCOMM INCORPORATED
    Inventors: Wanshi Chen, Juan Montojo, Xiliang Luo, Xiaoxia Zhang
  • Publication number: 20100202560
    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: Application
    Filed: February 1, 2010
    Publication date: August 12, 2010
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiliang Luo, Amir Farajidana, Xiaoxia Zhang, Juan Montojo
  • Publication number: 20100202561
    Abstract: Systems and methodologies are described herein that facilitate improved modulation and coding techniques for a multiple-in multiple-out (MIMO) communication system. As described herein, data to be transmitted over a set of physical layers (e.g., corresponding to antennas, beams, etc.) can be processed such that encoding is performed on a per-codeword basis and modulation is performed on a per-layer basis, thereby mitigating performance degradation experienced by traditional systems due to layer imbalance. As further described herein, per-codeword code rate parameters and per-layer modulation parameters can be signaled to a device in various manners, such as through modulation and coding scheme (MCS) signaling, explicit code rate and/or modulation scheme signaling, relative code rate and/or modulation scheme signaling, or the like.
    Type: Application
    Filed: February 8, 2010
    Publication date: August 12, 2010
    Applicant: QUALCOMM INCORPORATED
    Inventors: Alexei Y. Gorokhov, Juan Montojo, Xiaoxia Zhang, Peter Gaal, Xiliang Luo
  • Publication number: 20100202559
    Abstract: Techniques for transmitting data from multiple transmit antennas using space orthogonal resource transmit diversity (SORTD) are described. For the SORTD scheme, a different orthogonal resource may be assigned to each transmit antenna. Data may be sent from the multiple transmit antennas using multiple orthogonal resources. In one design, a UE may process at least one information bit (e.g., with joint or independent coding) to obtain first and second sets of at least one modulation symbol. The UE may process the first set of modulation symbol(s) for transmission from the first transmit antenna using a first orthogonal resource. The UE may process the second set of modulation symbol(s) for transmission from the second transmit antenna using a second orthogonal resource. Each orthogonal resource may include a different reference signal sequence or a different set of reference signal sequence and orthogonal sequence.
    Type: Application
    Filed: January 14, 2010
    Publication date: August 12, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Xiliang Luo, Peter Gaal, Wanshi Chen, Juan Montojo, Xiaoxia Zhang
  • Publication number: 20100195759
    Abstract: Systems and methodologies are described that facilitate cycling through precoders for transmitting wireless network communications in a time domain. The precoders can be cycled according to a precoder sequence for each data symbol transmission. When the last precoder is selected the cycle can begin again, a new precoder sequence can be received or defined, and/or the like. A precoder sequence related to a subset of precoders present in a wireless device can be defined sequentially, cyclically shifted according to an identifier or one or more communications parameters, randomly, pseudo-randomly according to an identifier or one or more communications parameters, and/or the like. In addition, the precoder sequence can be utilized to select a precoder for one or more retransmissions. Such cycling of precoders can increase transmit diversity.
    Type: Application
    Filed: February 1, 2010
    Publication date: August 5, 2010
    Applicant: QUALCOMM INCORPORATED
    Inventors: Peter Gaal, Xiliang Luo, Wanshi Chen, Juan Montojo, Xiaoxia Zhang