Patents by Inventor Zhifeng Tao

Zhifeng Tao 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: 8750159
    Abstract: A system for self-organizing and auto-configuring mesh networks is disclosed. Special nodes (deemed special for their topological significance) are used as a starting point for forming clusters of fully connected nodes. Here, all nodes can communicate directly with one another and links are scheduled to meet the traffic requirements as indicated by their individual configuration and topological positions. Links that do not interfere with each other are scheduled to operate concurrently, thereby increasing the bandwidth offered by the whole system. When a node leaves or is introduced to the system, the system will adjust with minimum impact on its operation. Once all of the clusters are formed in a system, the clusters are now capable of inter-cluster communications with an increase in bandwidth for such communications.
    Type: Grant
    Filed: October 20, 2008
    Date of Patent: June 10, 2014
    Assignee: Natural Lighting Systems, Inc.
    Inventors: Alexander L. Cheng, Zhifeng Tao
  • Patent number: 8599741
    Abstract: The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit, and an indication whether the PDU is a relay media access protocol data unit or not.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: December 3, 2013
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Jinyun Zhang
  • Patent number: 8493026
    Abstract: A method for facilitating an operation of an ad-hoc energy exchange network is disclosed. The network includes a set of nomadic charging stations (NCSs) and an energy consumer (EC). Upon receiving a request from the EC for an energy exchange, wherein the request includes a current location and a destination location of the EC, an exchange location for performing the energy exchange between a nomadic charging station (NCS) and the EC is determined based on the current location of the EC, the destination location of the EC, and a current location of the NCS. The exchange location is transmitted to the NCS and the EC.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: July 23, 2013
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zafer Sahinoglu, Zhifeng Tao, Koon Hoo Teo
  • Patent number: 8315205
    Abstract: A wireless network with a star topology has a first and second central node. The first central node starts up first and initiates the network. The second central node starts up second and synchronizes to the first central node, and wherein one node is in active mode and the other node is in standby mode, and a set of leaf nodes configured to communicate only with the active node.
    Type: Grant
    Filed: January 3, 2010
    Date of Patent: November 20, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Chunjie Duan, Jianlin Guo, Zhifeng Tao
  • Patent number: 8274930
    Abstract: A base station transmits a set of sounding requests to a set of mobile station (MS) in a cell, using a set of beams, wherein there is one beam for each sounding request. Qualities of sounding signals transmitted by the set of MSs in response to receiving the sounding request are measured, and the set of MSs are grouped into subsets according to the qualities, wherein there is one subset of MSs associated with each beam.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: September 25, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Philip V. Orlik, Toshiyuki Kuze, Andreas F. Molisch, Zhifeng Tao, Jinyun Zhang
  • Publication number: 20120236780
    Abstract: The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit, and an indication whether the PDU is a relay media access protocol data unit or not.
    Type: Application
    Filed: March 16, 2012
    Publication date: September 20, 2012
    Inventors: Zhifeng Tao, Jinyun Zhang
  • Patent number: 8270313
    Abstract: Embodiments of the invention disclose a system and a method for determining a rank of a node in a multi-hop wireless network, wherein the network includes a gateway node, client nodes, and relay nodes, wherein a node p(i) is a default parent of the node i having a rank, and the network uses a directed acyclic graph (DAG) topology. The method comprises steps of transmitting at least one data packet from the node to the default parent node over a wireless link; counting a number of successful transmissions of most recent transmissions of data packets; determining an expected transmission time (ETX) for the wireless link based on the number of successful transmissions in the most recent transmissions; and assigning a rank R(i) to the node based on the rank of the parent node and the ETX.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: September 18, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Di Wang, Jinyun Zhang
  • Patent number: 8228883
    Abstract: A wireless network master node periodically broadcasts beacons that specify a structure of a following fixed length superframe. Slave nodes determine a channel condition between each slave and the master. Then, the set of slaves is partitioned into subsets of slaves according to the channel conditions. The master assigns, to each slave, a transmission rate in a low to high order according to the channel conditions, and the slaves transmit data to the master in the low to high order between two consecutive beacons, wherein the subsets of slaves with a higher transmission rate also receive the data from the subsets of slaves with a lower transmission rate, and wherein a slave with a higher transmission rate includes a part of or all the data from a slave with a lower transmission rate.
    Type: Grant
    Filed: January 4, 2010
    Date of Patent: July 24, 2012
    Assignee: Mitsubishi Electric Research Labortories, Inc.
    Inventors: Raymond Yim, Zhifeng Tao, Zafer Sahinoglu, Man-On Pun
  • Patent number: 8223705
    Abstract: A method optimizes a performance of a multi-cell orthogonal frequency-division multiple access (OFDMA) network that includes a set of base stations (BSs) located in a cell, and each BS transmits data on downlink channels to a set of mobile stations (MSs) in the cell. Each BS acquires channel state information (CSI) and inter-cell interference information (ICI) for each downlink channel to each MS in the cell. Each BS selects a power level and a modulation coding scheme level (MCS) for transmitting the data to each MS on the downlink channels based on the CSI and ICI, such that a bit rate is maximized and the ICI is minimized. Then, time and frequency resource are allocated for transmitting the data on the downlink channels to the set of MSs, such that the allocated resources are minimized to optimize the performance of the network.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: July 17, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Philip V. Orlik, Toshiyuki Kuze
  • Patent number: 8218523
    Abstract: A network includes a master node (master) and a set of slave nodes (slaves). The network uses orthogonal frequency-division multiplexing (OFDM) and time division multiple access (TDMA) symbols on sub-carriers. During a first downlink transmission from the master to the set of slaves using downlinks and all of the sub-carriers, a broadcast polling packet including data packets for each slave and sub-carrier assignments for the slaves is broadcast. Each slave transmits simultaneously to the master using uplinks and the assigned sub-carriers, a first response packet after receiving the broadcast polling packet. The master then broadcasts using the downlinks and all of the sub-carriers, a group acknowledgement packet, wherein the broadcast polling packet, the response packet, and the group acknowledgement packet include one superframe in one communication cycle, and wherein the broadcasting on the downlinks and the transmitting on the uplinks are disjoint in time.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: July 10, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Philip V. Orlik, Zafer Sahinoglu, Andreas F. Molisch, Jinyun Zhang
  • Patent number: 8179990
    Abstract: A method transmits a sequence of symbols in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas. The sequence of symbols is represented by a vector S=[S1 S2 S3 S4]T of individual symbols, where T is a transpose operator. The individual symbols are transmitted as a transmit matrix S = [ S 1 - S 2 * S 1 - S 2 * S 2 S 1 * S 2 S 1 * S 3 - S 4 * - S 3 S 4 * S 4 S 3 * - S 4 - S 3 * ] , where * is a complex conjugate, and wherein each column of the matrix S represents the symbols transmitted at each transmission interval, and subscripts index the set of transmit antennas.
    Type: Grant
    Filed: September 17, 2008
    Date of Patent: May 15, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Philip V. Orlik, Wataru Matsumoto, Andreas F. Molisch, Zhifeng Tao, Jinyun Zhang
  • Patent number: 8175035
    Abstract: A method allocates resources in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations (BSs), and a set of mobile stations (MSs) for each BS. Each cell includes a center and edge zone. A node weighted constraint graph is constructed for the network. Maximal independent sets in the graph are searched as sub-channels are allocated to the MSs in edge zones. Remaining bandwidth is allocated to the MSs in the center zones. Power is assigned to the sub-channels so that inter-cell interference is minimized and traffic load is maximized.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: May 8, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Jinyun Zhang, Weihuang Fu
  • Patent number: 8175003
    Abstract: When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: May 8, 2012
    Assignee: Polytechnic University
    Inventors: Shivendra S. Panwar, Pei Liu, Zhifeng Tao
  • Patent number: 8165058
    Abstract: The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit; and an indication whether the PDU is a relay media access protocol data unit or not.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: April 24, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Jinyun Zhang
  • Patent number: 8165098
    Abstract: A method allocates bandwidth from a radio frequency spectrum in a cellular network including a set of cells. Each cell includes a base station for serving a set of mobile stations in the cell. An area around each base station is partitioned into a center region and an edge region. In each base station, cell-center bandwidth for use by the mobile stations in the center region is reserved according to an inter-cell interference coordination (ICIC) protocol, and cell-edge bandwidth for use by the mobile stations in the edge region is reserved according to the ICIC protocol. The bandwidth can be fixed or adaptive to reduce the signaling overhead. The adaptive bandwidth can be further partitioned into reserved and the free bands. Mobile stations are classified as primary and secondary users, depending on whether they use or are assigned the fixed or adaptive band radio resources.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: April 24, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Koon Hoo Teo, Zhifeng Tao, Xuehong Mao, Amine Maaref
  • Patent number: 8159983
    Abstract: A method communicates packets in a relay network. Multiple packets are communicated between a set of mobile stations and a relay station using a set of connections. There is one connection between each mobile station and the relay station. The multiple packets are aggregated on single connection between the relay station and a base station.
    Type: Grant
    Filed: November 6, 2006
    Date of Patent: April 17, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Koon Hoo Teo, Toshiyuki Kuze, Jinyun Zhang
  • Patent number: 8144657
    Abstract: A method allocates resource in an Orthogonal Frequency-Division Multiple Access (OFDMA) network, including a set of Base Stations (BSs) and a set of Mobile Stations (MSs) for each BS. OFDMA frame are constructed as multiple resource blocks, and each resource block contains symbols transmitted on different subcarriers. A cluster is formed from adjacent sectors of different neighboring cells to jointly optimize the resource allocation in multiple frames, and three non-overlap zones are sequentially identified in cluster: cell center zone, cell edge zone, and cluster corner zone. Resource allocation includes intra-cluster proportional fair scheduling and inter-cluster interference mitigation. Intra-cluster scheduling further includes resource allocation for cell center zone and resource allocation for cell edge zone.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: March 27, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Weihuang Fu, Jinyun Zhang
  • Publication number: 20120041804
    Abstract: A method for facilitating an operation of an ad-hoc energy exchange network is disclosed. The network includes a set of nomadic charging stations (NCSs) and an energy consumer (EC). Upon receiving a request from the EC for an energy exchange, wherein the request includes a current location and a destination location of the EC, an exchange location for performing the energy exchange between a nomadic charging station (NCS) and the EC is determined based on the current location of the EC, the destination location of the EC, and a current location of the NCS. The exchange location is transmitted to the NCS and the EC.
    Type: Application
    Filed: February 11, 2011
    Publication date: February 16, 2012
    Inventors: Zafer Sahinoglu, Zhifeng Tao, Koon Hoo Teo
  • Patent number: 8073071
    Abstract: A method transmits a block of symbols in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas. A block of symbols is coded with a first code to generate a first block, which is transmitted and received. If a decoding of the first block is incorrect, then block of symbols is coded with the first code and then a second code different than the first code to generate a second block. The second block is transmitted, received and combined with the first block to recover the block of symbols.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: December 6, 2011
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Philip V. Orlik, Wataru Matsumoto, Andreas F. Molisch, Zhifeng Tao, Jinyun Zhang
  • Patent number: D927065
    Type: Grant
    Filed: August 20, 2019
    Date of Patent: August 3, 2021
    Assignee: HANGZHOU LONGWEI TECHNOLOGY CO., LTD.
    Inventor: Zhifeng Tao