Patents by Inventor Fengjun Xi

Fengjun Xi 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: 20120177011
    Abstract: A method and apparatus for signaling for multi-antenna transmission with precoding are disclosed. Precoder phase information may be signaled using bit sequences that provide a degree of error tolerance in that precoder phases having large differences are signaled using bit sequences having large Hamming distances.
    Type: Application
    Filed: December 30, 2011
    Publication date: July 12, 2012
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Fengjun XI, Benoit PELLETIER, Lujing CAI, Hong O. ZHANG, Joseph S. LEVY, Diana PANI, Yingxue K. LI
  • Publication number: 20120176947
    Abstract: A method and apparatus for sending feedback for multi-cell high speed downlink packet access (HSDPA) operations are disclosed. A wireless transmit/receive unit (WTRU) may generate and send hybrid automatic repeat request acknowledgement (HARQ-ACK) messages and/or channel quality indication (CQI) or precoding control indication/channel quality indication (PCI/CQI) messages for a plurality of cells via a plurality of high speed dedicated physical control channels (HS-DPCCHs) with a spreading factor of 128. Each HARQ-ACK message may be mapped to two cells and each CQI or PCI/CQI message may be mapped to one cell. The cells may be remapped to an HARQ-ACK message and a CQI or PCI/CQI message within an HS-DPCCH on a condition that any cell is activated or deactivated on that HS-DPCCH.
    Type: Application
    Filed: January 6, 2012
    Publication date: July 12, 2012
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Fengjun Xi, Lujing Cai, Joseph S. Levy, Janet A. Stern-Berkowitz
  • Publication number: 20120082192
    Abstract: Method and apparatus for transmitting pilot on multiple antennas are disclosed. A wireless transmit/receive unit (WTRU) may transmit a primary dedicated physical control channel (DPCCH) and at least one secondary DPCCH via multiple antennas using different channelization codes. The first eight pilot symbols of the secondary DPCCH may be same as pilot symbols of length eight of the primary DPCCH. The secondary DPCCH may include a same number of pilot bits as the primary DPCCH in a normal mode and in a compressed mode, respectively. The transmit power of the secondary DPCCH may be adjusted based on a ratio of a number of pilot symbols in the primary DPCCH and the secondary DPCCH. When a required transmit power exceeds a maximum allowed transmit power of the WTRU, power scaling may be applied equally to the primary DPCCJ and the secondary DPCCH.
    Type: Application
    Filed: September 30, 2011
    Publication date: April 5, 2012
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Benoit Pelletier, Lujing Cai, Hong Zhang, Fengjun Xi, Joseph S. Levy
  • Publication number: 20120008510
    Abstract: Systems, methods, and instrumentalities are disclosed to provide antenna transmit diversity. A wireless transmit/receiver unit (WTRU) may comprise multiple antennas. A channel condition for each of the antennas may be determined. A probing phase may be used in order to determine the channel conditions. During a period of the probing phase, a probing signal from each antenna may be transmitted during a respective time interval. The WTRU transmit power may or may not be held constant. A Node B may receive each probing signal and determine channel quality information. The Node B may adjust the determined channel quality information if there is a power offset between the signals. The Node B may send the channel quality information to the WTRU. The WTRU may switch an antenna to use for uplink transmission based on the received channel quality information.
    Type: Application
    Filed: January 7, 2011
    Publication date: January 12, 2012
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Lujing Cai, Benoit Pelletier, Fengjun Xi, Joseph S. Levy, Andrew Irish
  • Publication number: 20110263281
    Abstract: A method for dynamically controlling the transmit power of transmission streams transmitted via multiple antennas is disclosed. A transmit power level for multiple streams is determined based on a first reference channel. The difference of signal to interface ratios (SIRs) between two reference channels may represent a power offset. The power offset may be used to determine gain factors used to transmit data channels on the secondary stream with reference to the gain factor of the first reference channel. The power offset may be used to determine other parameters, such a serving grant or transport block sizes of channels carried on the secondary stream. The power offset may allow transmission parameters of channels on the secondary stream to be determined based on the transmit power level of the primary stream and a gain factor for a reference channel transmitted via the primary stream.
    Type: Application
    Filed: April 8, 2011
    Publication date: October 27, 2011
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Lujing Cai, Benoit Pelletier, Hong O. Zhang, Fengjun Xi
  • Publication number: 20110249656
    Abstract: Feedback information for multiple serving cells are transmitted on high speed dedicated physical control channel (HS-DPCCH). A slot format for transmitting feedback information is determined based on the number of configured secondary serving cells and whether multiple input multiple-output (MIMO) is configured in the serving cells. Spreading factor is reduced to 128 when two secondary serving cells are configured and MIMO is configured in at least one of the two configured secondary serving cells, or when three secondary serving cells are configured. The serving cells are grouped into feedback groups, each feedback group having one or more serving cells. Channel coding may be applied to feedback information for the feedback groups. The resulting encoded feedback information for the feedback groups is concatenated to form composite feedback information.
    Type: Application
    Filed: February 14, 2011
    Publication date: October 13, 2011
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Lujing Cai, Benoit Pelletier, Hong O. Zhang, Fengjun Xi, Yan Li, Yingxue K. Li, Christopher R. Cave
  • Publication number: 20110170420
    Abstract: Method and apparatus for multi-carrier/multi-cell discontinuous reception (DRX)/discontinuous transmission (DTX) operations, autonomous deactivation of the secondary carrier(s)/cell(s), and explicit activation/deactivation of DRX/DTX and secondary carriers/cells are disclosed. A user equipment (UE) may configure at least one state variable for controlling DRX and/or DTX on a plurality of cells and perform an DRX and/or DTX operation on a subset of cells based on a state variable associated with the subset of cells on a cell group basis. The UE may activate or deactivate DRX and/or DTX based on an order from a network for all cells, a group of cells, or an individual cell. The UE may deactivate the secondary cells autonomously based on activity on the cell(s).
    Type: Application
    Filed: January 7, 2011
    Publication date: July 14, 2011
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Fengjun Xi, Diana Pani, Christopher R. Cave, Benoit Pelletier, Lujing Cai
  • Publication number: 20110080972
    Abstract: Method and apparatus for uplink transmission using multiple antennas are disclosed. A wireless transmit/receive unit (WTRU) performs space time transmit diversity (STTD) encoding on an input stream of a physical channel configured for STTD. Each physical channel may be mapped to either an in-phase (I) branch or a quadrature-phase (Q) branch. The WTRU may perform the STTD encoding either in a binary domain or in a complex domain. Additionally, the WTRU may perform pre-coding on at least one physical channel including the E-DPDCH with the pre-coding weights, and transmitting the pre-coded output streams via a plurality of antennas. The pre-coding may be performed either after or before spreading operation.
    Type: Application
    Filed: September 30, 2010
    Publication date: April 7, 2011
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Fengjun Xi, Lujing Cai, Hong Zhang, Benoit Pelletier
  • Publication number: 20100273520
    Abstract: Methods and apparatus for power scaling for multi-carrier wireless terminals are disclosed. Methods and mechanisms are provided for power scaling when a multi-carrier WTRU reaches its maximum output power.
    Type: Application
    Filed: April 23, 2010
    Publication date: October 28, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Benoit Pelletier, Diana Pani, Joseph S. Levy, Fengjun Xi, Christopher R. Cave
  • Publication number: 20100246516
    Abstract: A method and apparatus for performing uplink (UL) transmit diversity implemented in a wireless transmit/receive unit (WTRU) includes receiving a signal including precoding information. The precoding information is detected and applied to an UL transmission. The UL transmission is transmitted with the applied precoding information.
    Type: Application
    Filed: March 12, 2010
    Publication date: September 30, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Benoit Pelletier, Paul Marinier, Christopher R. Cave, Fengjun Xi
  • Publication number: 20100157895
    Abstract: A method and an apparatus for uplink transmission using multiple uplink carriers are disclosed. A wireless transmit/receive unit (WTRU) selects a dedicated channel medium access control (MAC-d) flow with highest priority data to be transmitted and performs uplink carrier selection and enhanced dedicated channel (E-DCH) transport format combination (E-TFC) restriction and selection to select a carrier among a plurality of carriers and select an E-TFC based on a maximum supported payload, a remaining scheduled grant payload of the selected carrier and a remaining non-scheduled grant payload. The WTRU then generates a medium access control (MAC) protocol data unit (PDU) for E-DCH transmission via the selected carrier based on the selected E-TFC.
    Type: Application
    Filed: October 31, 2009
    Publication date: June 24, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Diana Pani, Paul Marinier, Christopher R. Cave, Benoit Pelletier, Fengjun Xi
  • Publication number: 20100130137
    Abstract: Methods and apparatus for multiple carrier utilization in wireless communications are disclosed. These methods include multiple carrier activation/deactivation, multiple carrier discontinuous transmission (DTX) and discontinuous reception (DRX) activation/deactivation and operations, and multiple carrier acknowledgment/negative acknowledgement feedback. The methods include provisions for joint multiple carrier activation and deactivation and joint DTX and DRX activation and deactivation of multiple carriers.
    Type: Application
    Filed: November 20, 2009
    Publication date: May 27, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Benoit Pelletier, Christopher R. Cave, Fengjun Xi, Diana Pani, Paul Marinier