Patents by Inventor Chunjie Duan

Chunjie Duan 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: 20100246375
    Abstract: A method allocates bandwidth to channels in an orthogonal frequency division multiple access and time division multiple access (TDMA) network. The network includes a master device (master) communicating with a set of slave devices (slaves). The master defines a set ?m of logical indices ? of a set of N physical subcarriers for a set of M data streams to be allocated to a set of Nd logical data subcarriers according to ?m={?|?=iM+m, i=0,1,2, . . . , d?1}, where d=Nd/M. The set of N data subcarriers is mapped to the set of Nd logical subcarriers according to the logical indices, and the data subcarriers are allocated to the logical subcarriers.
    Type: Application
    Filed: July 15, 2009
    Publication date: September 30, 2010
    Inventors: Philip V. Orlik, Qinghe Du, Zafer Sahinoglu, Chunjie Duan, Jinyun Zhang
  • Publication number: 20100203839
    Abstract: A method measures a time from transmitting a ranging signal to receiving the ranging signal via a channel of a wireless network, and a received signal strength (RSS) of the ranging signal. A distance is estimated based on the time, and a path loss based on the RSS. Probabilities of conditions of the channel are estimated based on the distance and the path loss, wherein the condition is in one of line-of-sight (LOS), or non-LOS (NLOS).
    Type: Application
    Filed: February 10, 2009
    Publication date: August 12, 2010
    Inventors: Chunjie Duan, Nayef Alsindi, Jinyun Zhang
  • Publication number: 20100172339
    Abstract: A method and system improves two-way radio ranging accuracy by estimating a relative clock frequency offset between a first clock X of a first transceiver and a second clock Y a second transceiver. The first transceiver transmits a first packet at time t0 received by the second transceiver at a time t1. The second transceiver transmits a second packet at a time t2 received by first transceiver at a time t3. The second transceiver transmits a third packet at a time t4 received at a time t5. The relative clock frequency offset is then ? ? ? f XY ? ? 2 ? ? f ? ( N 24 Y - N 35 X ) N 24 Y + N 35 X , where f is a nominal clock frequency of the first and second clocks, NY24 is a measured first delay between times t2 and t4 of the second clock, NX35 is a measured second delay between times t3 and t5 of the first clock X.
    Type: Application
    Filed: December 19, 2007
    Publication date: July 8, 2010
    Inventors: Chunjie Duan, Giovanni Vannucci
  • Publication number: 20100165916
    Abstract: A wireless network with a star topology includes a first central node, a second central node, wherein the first and second nodes are functionally equivalent. A set of leaf nodes are configured to communicate with either the first central node or the second central node via wireless links, depending whether the central nodes are active or inactive.
    Type: Application
    Filed: December 31, 2008
    Publication date: July 1, 2010
    Inventors: Chunjie Duan, Jinyun Zhang, Philip Orlik
  • Publication number: 20090296684
    Abstract: Synchronization methods and systems for communications over a multi-band system are presented. A synchronization technique for communications over a multi-band system includes receiving a packet of preamble symbols respectively transmitted over a sequence of frequency sub-bands according to one of a plurality of frequency hopping patterns, wherein the plurality of frequency hopping patterns are partitioned into a plurality of disjoint groups, each group having a different associated periodicity; computing, in parallel, respective autocorrelation values of the packet received in a selected frequency sub-band at a plurality of symbol delays; and selecting one of the plurality of groups of frequency hopping patterns based on the autocorrelation values at the plurality of symbol delays.
    Type: Application
    Filed: May 19, 2009
    Publication date: December 3, 2009
    Applicant: Renesas Technology Corporation
    Inventors: Zhenzhen Ye, Chunjie Duan, Philip Orlik, Jinyun Zhang
  • Publication number: 20090237279
    Abstract: Embodiments of our invention describe the method for producing forbidden pattern free (FPF) codewords using an encoder-decoder (CODEC). First, the method encodes a dataword to produce a FPF codeword by mapping dataword to a Fibonacci Numeral System space. Further, the FPF codeword is transmitted via adjacent lines of a bus and decoded when received from the bus to recover the dataword to eliminate all crosstalk on the bus.
    Type: Application
    Filed: March 19, 2008
    Publication date: September 24, 2009
    Inventor: Chunjie Duan
  • Patent number: 7583209
    Abstract: Embodiments of our invention describe the method for producing forbidden pattern free (FPF) codewords using an encoder-decoder (CODEC). First, the method encodes a dataword to produce a FPF codeword by mapping dataword to a Fibonacci Numeral System space. Further, the FPF codeword is transmitted via adjacent lines of a bus and decoded when received from the bus to recover the dataword to eliminate all crosstalk on the bus.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: September 1, 2009
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventor: Chunjie Duan
  • Publication number: 20090213816
    Abstract: A method for transmitting information in a communication network of multiple nodes, in which information transmission is partitioned into successive superframes, and in which each superframe is partitioned into a beacon period followed by a data period, which may consist of a contention free period (CFP), and each beacon period and CFP of the data period is partitioned into timeslots. The method includes allocating to at least a first node of the multiple nodes a designated timeslot in which to transmit data in at least one of a plurality of superframes, and allocating to at least a second node of the multiple nodes the same designated timeslot in which to transmit information during at least one subsequent superframe.
    Type: Application
    Filed: August 19, 2008
    Publication date: August 27, 2009
    Inventors: Jianlin Guo, Chunjie Duan, Ghulam M. Bhatti, Jinyun Zhang
  • Publication number: 20090080556
    Abstract: A method and system reduces a peak to average power ratio of a transmitted OFDM signal. An input signal is encoded using a forward error correcting code to produce a codeword corresponding to the input signal. A peak power corresponding to the codeword is measured. The peak power is compared with a predetermined threshold, and a set of selected bits in the codeword are manipulated if the peak power is greater than the predetermined threshold to deliberately produce an erroneous codeword in which the peak power is less than the predetermined threshold, which is transmitted.
    Type: Application
    Filed: September 25, 2007
    Publication date: March 26, 2009
    Inventors: Chunjie Duan, Koon Hoo Teo
  • Publication number: 20080298513
    Abstract: An adaptive sliding block Viterbi decoder (ASBVD) includes forward and backward Viterbi processors, a state estimator and a control unit. The processors generate metrics of states and of transitions between the states associated with an encoder, based on encoded input information symbols received via a communications channel. Each processor includes a plurality of buffers for storing information symbols so that a number of the encoded input information symbols can be concurrently decoded. The state estimator estimates a current state of a code trellis based on the generated metrics, and the processors decode the stored information symbols based on the estimated current state. The control unit adapts the number of encoded input information symbols to be concurrently decoded based on a condition of the communications channel, and selectively controls the number of buffers that are enabled in accordance with the number of encoded input information symbols to be concurrently decoded.
    Type: Application
    Filed: May 31, 2007
    Publication date: December 4, 2008
    Inventors: Sinan Gezici, Chunjie Duan, Jinyun Zhang, Rajesh Garg
  • Publication number: 20080297133
    Abstract: A dynamic voltage scaling system for a packet-based data communication transceiver includes a constant voltage supply, a variable voltage supply, and a voltage control unit. The constant voltage supply is configured to supply a constant voltage to at least one parameter-independent function of the transceiver, and the variable voltage supply is configured to supply a variable voltage in accordance with a control signal to at least one parameter-dependent function of the transceiver. Parameter-independent transceiver functions perform operations independent of a predetermined parameter and parameter-dependent transceiver functions perform operations dependent on the predetermined parameter The voltage control unit is configured to generate the control signal based on information provided by at least one parameter-independent transceiver function about the predetermined parameter.
    Type: Application
    Filed: May 31, 2007
    Publication date: December 4, 2008
    Inventors: Chunjie Duan, Sinan Gezici, Jinyun Zhang, Rajesh Garg