Patents by Inventor Wenfeng Zhang

Wenfeng Zhang 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: 8330529
    Abstract: Embodiments of a method, apparatus and circuit for voltage regulation are disclosed. One embodiment of a circuit includes a first field effect transistor (FET) having a gate, a drain and a source. A current source is connected to the drain of the FET. A second FET has a source connected to the source of the first FET by a node. The second FET also has a gate. A low-pass filter circuit has an input connected to the gate of the first FET and an output connected to the gate of the second FET.
    Type: Grant
    Filed: January 28, 2010
    Date of Patent: December 11, 2012
    Assignee: Xilinx, Inc.
    Inventors: Wenfeng Zhang, Qi Zhang
  • Publication number: 20120300670
    Abstract: Disclosed in the present invention is a pre-coding method for hybrid multiplexing demodulation reference symbol (DMRS). The method includes: determining a multiplexing relationship between DMRS ports; making layers of data transport correspond to DMRS ports with the multiplexing relationship determined; and pre-coding pilot sequences corresponding to various DMRS ports according to the relationship between the layers of data transport and the DMRS ports. Also disclosed in the present invention is a method for mapping from a layer to a multiplexing demodulation reference symbol (DMRS) and an apparatus for achieving pre-coding based on a hybrid multiplexing demodulation reference symbol (DMRS). By way of the technical solution of the present invention, interference between the layers corresponding to different codeword streams can be avoided, and the accuracy of channel estimation can be improved.
    Type: Application
    Filed: December 17, 2010
    Publication date: November 29, 2012
    Applicant: ZTE CORPORATION
    Inventors: Yunfeng Sun, Wenfeng Zhang, Jing Jiang, Junfeng Zhang
  • Publication number: 20120294206
    Abstract: Techniques, apparatuses, and systems for dynamically changing downlink and uplink allocations can include operating a base station under time division duplexing to communicate with one or more mobile devices using a frame structure, adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in the frame structure, determining a mute interval based on the adjusted downlink-uplink ratio, generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change, and transmitting the mute information to the one or more mobile devices.
    Type: Application
    Filed: July 30, 2012
    Publication date: November 22, 2012
    Applicant: ZTE (USA) INC.
    Inventors: Wenfeng Zhang, Yonggang Fang
  • Publication number: 20120270591
    Abstract: The present disclosure discloses a transmission power configuration method for a Demodulation Reference Signal (DMRS), and the method comprises: configuring the ratio between transmission power of a DMRS at each layer in a Resource Element (RE) and transmission power of data at a corresponding layer to be a constant value. Meanwhile, the present disclosure discloses a transmission power configuration apparatus for the DMRS. The present disclosure greatly improves the correct rate of data frame decoding, and improves decoding performance. The present disclosure enables the network side not need to notify a UE of the corresponding relationship between transmission power of DMRS at each layer and transmission power of data at the corresponding layer, which simplifies the overhead of the control signalling in the network side.
    Type: Application
    Filed: October 20, 2010
    Publication date: October 25, 2012
    Applicant: ZTE Corporation
    Inventors: Yunfeng Sun, Wenfeng Zhang, Jing Jiang, Junfeng Zhang
  • Publication number: 20120210551
    Abstract: A vertical turning-milling complex machining center comprises a horizontally-arranged bed body (6) and a vertically-arranged column (7). The bed body (6) is provided with an X-axis lateral supporting linear track (2) and an X-axis guide screw (5). The bed body (6) is also provided with a uniaxial rotating table (1) which can reciprocate and is driven directly by a first external rotor torque motor. The column (7) is vertically provided with a Z-axis lateral supporting linear track (10), a Z-axis guide screw (9) and a crossbeam (11) that reciprocates up and down. The crossbeam (11) is provided with a transverse Y-axis linear track (13), a Y-axis guide screw (12) and a single-pendulum milling head seat frame that can reciprocate along the Y-axis guide screw (12). The single-pendulum milling head is driven directly by a second external rotor torque motor.
    Type: Application
    Filed: October 29, 2010
    Publication date: August 23, 2012
    Applicant: DALIAN KEDE NUMERICAL CONTROL CO., LTD.
    Inventors: Dehai Yu, Chungang Cai, Zhihui Ren, Wenfeng Zhang, Hu Chen, Junmin Zheng, Qiang Guo, Tao Zou, Jingming Li, Peng Qu, Yang Lin
  • Patent number: 8233413
    Abstract: Techniques, apparatuses, and systems for dynamically changing downlink and uplink allocations can include operating a base station under time division duplexing to communicate with one or more mobile devices using a frame structure, adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in the frame structure, determining a mute interval based on the adjusted downlink-uplink ratio, generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change, and transmitting the mute information to the one or more mobile devices.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: July 31, 2012
    Assignee: ZTE (USA) Inc.
    Inventors: Wenfeng Zhang, Yonggang Fang
  • Publication number: 20120188955
    Abstract: Systems and methods for transmitting a physical downlink shared channel (PDSCH) of spatial-frequency block coding (SFBC) format in a subframe that includes at least one of a channel state information reference signal (CSI-RS) and zero-power muting are disclosed. A processor unit is groups one or more resource elements (REs) available for at least one of CSI-RS and zero-power muting, and the subframe including the group of one or more REs is transmitted. All of the one or more REs in a group may be used for PDSCH rate matching together, or none of the one or more REs in the group may be used for PDSCH rate matching. All REs on one OFDM symbol may not be used for PDSCH rate matching if any two REs per SFBC pair on the OFDM symbol, are separated by at least N REs, where N is equal to 1 or 2.
    Type: Application
    Filed: January 20, 2012
    Publication date: July 26, 2012
    Applicant: ZTE (USA) INC.
    Inventor: Wenfeng ZHANG
  • Patent number: 8209576
    Abstract: A method for dynamic adjustment of downlink/uplink resource allocation ratio in a long-term evolution (LTE) time division duplex (TDD) system is disclosed. The method includes replacing at least one of an uplink subframe and a downlink subframe with a mute subframe in a subframe pattern, indicating a first downlink/uplink resource allocation ratio. Thereafter, the mute subframe is replaced with either the uplink subframe or the downlink subframe to form another subframe pattern. The subframe pattern including the mute subframe is obtained from a lookup table, such that the replacing the mute subframe results in the other pattern. A data transmission in accordance with the other subframe pattern, indicating a second downlink/uplink resource allocation ratio, may be scheduled. Hybrid Automatic Repeat-request (HARQ) processing may be implemented after the at least one of the uplink subframe and the downlink subframe is replaced with the mute subframe in the first subframe pattern.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: June 26, 2012
    Assignee: ZTE (USA) Inc.
    Inventor: Wenfeng Zhang
  • Publication number: 20120120854
    Abstract: A method and system for dynamic adjustment of downlink/uplink resource allocation ratio in a long-term evolution (LTE) time division duplex (TDD) system is disclosed. The method includes replacing at least one uplink subframe in a subframe pattern with at least one of a mute subframe and a mute uplink pilot timeslot (UpPTS), within a geographical guard area that isolates at least two areas having different TDD allocation patterns. The method further includes scheduling an uplink transmission from at least one mobile terminal such that the at least one of the mute subframe and the mute UpPTS are unused. A simple solution or a TDD configuration index substitution solution, or any combination thereof, may be used to control the uplink transmission involving a mute subframe or a mute UpPTS.
    Type: Application
    Filed: April 27, 2010
    Publication date: May 17, 2012
    Applicant: ZTE (USA) INC.
    Inventors: Wenfeng Zhang, Yuhong Duan, Jian Hu, Zhifeng Ma, Zhongdang Du, Bin Yu
  • Patent number: 8134994
    Abstract: In the scheduling method of the present invention, scheduling grant messages for a user equipment are transmitted beginning in any time slot of a frame for a channel so long as the scheduling grant message does not exceed the frame. The scheduling grant message indicates user equipment is approved to transmit on an uplink dedicated channel. This downlink transmission and subsequent uplink dedicated channel transmission have a timing relationship such that no more than one user equipment will begin transmitting on a respective uplink dedicated channel at a time.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: March 13, 2012
    Assignee: Alcatel Lucent
    Inventors: Jung-Tao Liu, Wenfeng Zhang
  • Publication number: 20110189987
    Abstract: Methods and systems for femto-cell identification are disclosed herein. In one embodiment, a femto-cell base station is adapted to transmit with each broadcast a value which maps one-to-one to a different portion of a femto-cell identification. After the mobile station reports each broadcasted value to the serving non-femto-cell, the target femto-cell identification can be determined by combining multiple reports. In this manner, a fairly large identification space can be provided without significant increases in implementation complexity. In some embodiments, the system does not introduce issues with backward compatibility since standard cell identification procedures are preserved. In some embodiments, knowledge of the maximum number of femto-cells within a non-femto-cell is not required, thereby preventing ambiguous hand-in targets.
    Type: Application
    Filed: August 6, 2009
    Publication date: August 4, 2011
    Inventors: Wenfeng Zhang, Yonggang Fang
  • Patent number: 7839173
    Abstract: A system for signal level shifting in an IC can include a first inverter having a first pull-up device and a pull-down device, wherein the first inverter is operable to receive an input signal having a voltage potential at a logic high that does not disable the first pull-up device. The system can include a second inverter coupled in series to an output of the first inverter, and a control module coupled to the output of the first inverter and an output of the second inverter. Prior to the input signal transitioning to the logic high, the control module is operable to decouple the input signal from the first pull-up device, disable the first pull-up device, and close a feedback loop that latches an output state of the second inverter.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: November 23, 2010
    Assignee: Xilinx, Inc.
    Inventors: Wenfeng Zhang, Qi Zhang, Jian Tan
  • Patent number: 7792205
    Abstract: Techniques and devices for encoding and decoding a signal channel in a downlink signal in wireless communication systems, including the frame control header (FCH) data in IEEE 802.16 systems with reduced transmission power consumption, improved error correction capability, and reduced decoding complexity.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: September 7, 2010
    Assignee: ZTE (USA) Inc.
    Inventors: Wenfeng Zhang, Wenzhong Zhang, Jun Wu, Yonggang Fang
  • Publication number: 20100197309
    Abstract: Techniques, apparatuses, and systems for handling femto-cell hand-in requests can include operating a macro-cell base station to provide wireless service to wireless devices in a geographical coverage area; receiving, from a wireless device, a message indicative of the wireless device's reception of a base station radio signal, the message including a base station identifier; controlling multiple femto-cell base stations that are assigned to the base station identifier to communicate with the wireless device and to report a reception of a radio signal from the wireless device; and transferring the wireless device from the macro-cell base station to a femto-cell base station of the multiple femto-cell base stations that reports a reception of the radio signal from the wireless device. The multiple femto-cell base stations can provide wireless service in different nonadjacent portions of the geographical coverage area.
    Type: Application
    Filed: December 29, 2009
    Publication date: August 5, 2010
    Inventors: Yonggang Fang, Rajesh Bhalla, Wenfeng Zhang, Xiaowu Zhao
  • Publication number: 20100029278
    Abstract: Techniques, apparatuses, and systems for using identification sequences in a wireless communication system can include receiving information indicative of a pilot code detected by a wireless device, the pilot code being shared by multiple Femto Access Points (FAPs) that each provide wireless service in at least a portion of the coverage area; receiving information indicative of an identification sequence detected by the wireless device that is associated with the pilot code, using the information indicative of the identification sequence to identify one of the FAPs that share the pilot code; and performing a hand-off of the call to the identified FAP to continue to provide wireless service for the call via the identified FAP.
    Type: Application
    Filed: June 17, 2009
    Publication date: February 4, 2010
    Applicant: ZTE (USA) INC.
    Inventors: Yonggang Fang, Wenfeng Zhang, Rajesh Bhalla, Xiaowu Zhao
  • Publication number: 20090249153
    Abstract: A method for dynamic adjustment of downlink/uplink resource allocation ratio in a long-term evolution (LTE) time division duplex (TDD) system is disclosed. The method includes replacing at least one of an uplink subframe and a downlink subframe with a mute subframe in a subframe pattern, indicating a first downlink/uplink resource allocation ratio. Thereafter, the mute subframe is replaced with either the uplink subframe or the downlink subframe to form another subframe pattern. The subframe pattern including the mute subframe is obtained from a lookup table, such that the replacing the mute subframe results in the other pattern. A data transmission in accordance with the other subframe pattern, indicating a second downlink/uplink resource allocation ratio, may be scheduled. Hybrid Automatic Repeat-request (HARQ) processing may be implemented after the at least one of the uplink subframe and the downlink subframe is replaced with the mute subframe in the first subframe pattern.
    Type: Application
    Filed: March 24, 2009
    Publication date: October 1, 2009
    Inventor: Wenfeng ZHANG
  • Publication number: 20090207725
    Abstract: A method and system for joint encoding multiple independent information messages are disclosed. In one embodiment, a system includes an encoder configured to encode each of the independent information messages to produce respective encoded bits, and a first multiplexer configured to multiplex each of the independent information messages. A joint block encoder encodes the multiplexed independent information messages to produce encoded common parity bits shared by all independent information messages, and a second multiplexer multiplexes the respective encoded bits from all independent channel encoders and the encoded common parity bits from the joint block encoder to produce the final output.
    Type: Application
    Filed: February 10, 2009
    Publication date: August 20, 2009
    Inventor: Wenfeng ZHANG
  • Publication number: 20090201838
    Abstract: Techniques, apparatuses, and systems for dynamically changing downlink and uplink allocations can include operating a base station under time division duplexing to communicate with one or more mobile devices using a frame structure, adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in the frame structure, determining a mute interval based on the adjusted downlink-uplink ratio, generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change, and transmitting the mute information to the one or more mobile devices.
    Type: Application
    Filed: February 6, 2009
    Publication date: August 13, 2009
    Inventors: Wenfeng Zhang, Yonggang Fang
  • Patent number: 7430241
    Abstract: A system and method for transmitting and receiving control information over a control channel of a wireless communication system where the conveyed information is coded and then transformed by a set of transform function selected from a plurality of sets of transform functions. The control information is transmitted as replicated sub-frames containing replicated code words and such a string of transformed replicated code words is referred to as a control message. At a receive end inverse transform functions from different sets of functions are applied to a sub-frame of a control message so that if the sub-frame is successfully decoded the inverse transform function applied to such frame allows the timing of the control message to be determined.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: September 30, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Subramanian Vasudevan, Yunsong Yang, Wenfeng Zhang
  • Patent number: 7333457
    Abstract: A wireless data communication system includes a high speed dedicated physical control channel (EU-DPCCH) used with transmissions from a mobile device to support an uplink high speed data channel. In one example the EU-DPCCH has a sub frame structure that is the same as an associated dedicated data channel and a fixed spreading factor. The EU-DPCCH allows communicating control information from the mobile device such as a pilot reference, hybrid automatic repeat request information, and backlog information regarding a buffer of the mobile device.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: February 19, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Nandu Gopalakrishnan, Jung-Tao Liu, Wenfeng Zhang