Patents Assigned to Communications Research Laboratory of Ministry of Posts and Telecommunications
  • Patent number: 6832233
    Abstract: When numerically integrating an integrand function A over an unbounded domain, a vector map f converts an m (m≧1)-dimensional vector into an m-dimensional vector wherein a multidimensional density function &rgr; of the limiting distribution resulting from repeatedly applying the map f to a predetermined m-dimensional vector u is analytically solvable. A first storage unit stores an m-dimensional vector x, a second storage unit stores a scalar value w, a first computing unit computes a vector x′=f(x), a second computing unit computes a scalar value w′=A(x)/&rgr;(x), an update unit updates values in the first and second storage units and by storing the vector x′ on the first storage unit and adding the scalar value w′ to a value to be stored in the second storage unit, and an output unit computes a scalar value s=w/(c+1) when the number of update times by the update unit becomes c (c≧1) and outputs the result.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: December 14, 2004
    Assignees: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventor: Ken Umeno
  • Patent number: 6819782
    Abstract: An object of the present invention is to provide a device and a method for recognizing hand shape and position even if a hand image to be provided for recognition is rather complicated in shape, and a recording medium having a program for carrying out the method recorded thereon. A hand image normalization part 11 deletes a wrist region respectively from a plurality of images varied in hand shape and position before subjecting the images to normalization in hand orientation and size to generate hand shape images. An eigenspace calculation part 13 calculates an eigenvalue and an eigenvector respectively from the hand shape images under an analysis based on an eigenspace method. An eigenspace projection part 15 calculates eigenspace projection coordinates by projecting the hand shape images onto an eigenspace having the eigenvectors as a basis.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: November 16, 2004
    Assignees: Matsushita Electric Industrial Co., Ltd., Communications Research Laboratory of Ministry of Posts and Telecommunications
    Inventors: Kazuyuki Imagawa, Hideaki Matsuo, Seiji Igi, Shan Lu
  • Patent number: 6766172
    Abstract: A road vehicle communication method allows bothway communication to be held between a mobile station, which sends a request for an information service and receives it, and a central base station and local base stations located at a roadside for sending the information service to the mobile station. The central base station and the local base stations use optical fibers in part of the transmission path thereof for the bothway communication and perform at least one of electric-to-optical conversion and optical-to-electric conversion. The mobile station is caused to send the request for an information service beforehand. In response to the request, the local base station covering the mobile station expected to receive the information service is estimated. When the mobile station lies in a service area to which the local base station estimated is assigned, a control station is caused to provide the mobile station with information corresponding to the information service requested.
    Type: Grant
    Filed: September 19, 2000
    Date of Patent: July 20, 2004
    Assignees: Oki Electric Industry Co., Ltd., Communications Research Laboratory, Ministry of Posts and Telecommunications, Matsushita Communication Industrial Co., Ltd.
    Inventors: Kiyohito Tokuda, Kinya Asano, Masayuki Fujise, Fumihide Kojima, Masahiro Watanabe, Ryobun Tachita
  • Patent number: 6668265
    Abstract: A first storage in an apparatus for outputting a sequence of vectors stores vector x having the dimension at least 1, a first calculator calculates vector function x′=f(x) which utilizes a first rational vector map f to which the stored vector x is input, a second storage stores vector y having the dimension at least 1, a second calculator calculates vector function y′=g(x, y) which utilizes a second rational vector map g to which the stored vectors x and y are input, an output outputs vector z′ which is association of the resultant vectors x′ and y′, a first update updates the first storage by storing the resultant vector x′, and a second update updates the second storage by storing the resultant vector y′.
    Type: Grant
    Filed: March 20, 2000
    Date of Patent: December 23, 2003
    Assignees: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventor: Ken Umeno
  • Patent number: 6661831
    Abstract: A PN sequence output apparatus outputs a PN sequence which is generated by using a Chebyshev polynomial T(a, cos &thgr;)=cos(a &thgr;) for an integer a (2≦a) and which has a length N (1≦N). An accepting section accepts an S (1≦S) number of initial values X1, X2, . . . , Xs each of which is a real number larger than −1 and less than 1, and an S number of degrees p1, p2, . . . , ps each of which is an integral number equal to or larger than 2. A calculation section calculates a Pseudorandom Noise sequence, having a length N, z[1], z[2], . . . , z[N], using the initial values, the degrees, and recurrence formulas xj[1]=Xj, xj[m+1]=T (pj, xj[m]), and z[n]=Πj=1s T(pj, xj[n]), for integers j (1≦j≦S), m (1≦m≦N−1) and n (1≦n≦N). An output section outputs a PN sequence.
    Type: Grant
    Filed: August 18, 2000
    Date of Patent: December 9, 2003
    Assignees: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventor: Ken Umeno
  • Patent number: 6477481
    Abstract: A device for outputting stochastic process according to the present invention comprises a plurality of random variable output units, a normalizing unit, and a result output unit. Each of the random variable output units outputs a sequence of random variables whose limiting distribution obeys an explicit density function. The normalizing unit normalizes the sum of the random variables in the same row over the random variable sequences output by the random variable output units, and sequentially outputs the normalized values. The result output unit integrates the values sequentially output by the normalizing unit, and sequentially outputs the integrated values as result values in stochastic process. The random variable output units utilize a recurrence formula obtained by an addition formula of a tangent function, thus, efficient high speed simulation of the Lévy's stable processes is realized.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: November 5, 2002
    Assignees: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventor: Ken Umeno
  • Patent number: 6442146
    Abstract: The present invention is directed to a TDMA communication system which is adapted to different communication environments or prepares different communication environments and allows each mobile station to be set for working in any one of the different communication environments. The communication system commonly uses a TDMA format that has a fixed frame-length and a constant number of bits for each of the slots composing the frame. The communication environments have prepared respective sets of communication conditions, each set including a transmission power, a modulating method, the number of multiplexed signals, error-correction, an antenna gain, a frequency hopping value and a diversity value. At each mobile station and each base station, one of plural sets of communication conditions for respective environments is selected to establish communication with each other under the selected environment.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: August 27, 2002
    Assignees: Sharp Kabushiki Kaisha, Hitachi Ltd., Mitsubishi Denki Kabushiki Kaisha, Communication Research Laboratory, Ministry of Posts and Telecommunications, Nippon Telegraph And Telephone Corporation, NTT Mobile Communications Network, Inc., YRP Mobile Telecommunications Key Technology Research Laboratories Co. Ltd.
    Inventors: Tetsuo Onodera, Hiroshi Usami, Akihiro Shibuya, Eimatsu Moriyama, Kiyoshi Hamaguchi, Yoichi Saito, Tadashi Matsumoto, Mitsuhiko Mizuno
  • Patent number: 6388546
    Abstract: This invention provides a multistage frequency multiplier having a plurality of frequency doublers. Each doubler incorporates a three-terminal transistor device and is connected to an adjacent doubler via an interstage network. The network comprises a transmission line having its electrical parameters selected to achieve conjugate impedance matching at the intermediate harmonic frequency generated by the corresponding doubler. This network also includes a quarter-wavelength open-ended stub for suppressing a main input frequency component received by the corresponding frequency doubler. A shunt resistor on the transistor gate is preferably used to stabilize the network. This interstage network simplifies overall circuit topology to reduce total circuit size, and provides increased drive power levels to permit broader bandwidth and stabilize required output level from a local oscillator.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: May 14, 2002
    Assignees: Her Majesty The Queen In Right of Canada as represented by The Minister of Industry through the Communications Research Centre, The Communications Research Laboratory of the Ministry of Posts and Telecommunications, Japan
    Inventors: Masahiro Kikokawa, Malcolm G. Stubbs
  • Patent number: 6304689
    Abstract: A general multi-function optical filter for future smart, high density wavelength division multiplexed (WDM) communication and network system applications using a Michelson-GT interferometer (MGTI) is invented. MGTI filter is a typical Michelson interferometer in which one of its reflecting mirrors is replaced by Gires-Toumois resonator (GTR). One unique feature of this device is that it can function as channel passing, channel dropping and wide bandpass filters depending on the interferometer arm length difference. The output of these functions is available in a single port. Other interesting features of this element are (1) that linewidths of both channel dropping and channel passing filters are twice as narrow compared with typical Fabry-Perot filter having similar parameters, (2) that visibility of the output for three functions is always unity regardless of the mirror reflectance value, and (3) that bandpass filter has an excellent, near-perfect, box-like response function.
    Type: Grant
    Filed: January 8, 1999
    Date of Patent: October 16, 2001
    Assignee: Communications Research Laboratory Ministry of Posts and Telecommunications
    Inventors: Benjamin Dingel, Masayuki Izutsu
  • Patent number: 6263146
    Abstract: An apparatus for optically generating chaotic random numbers to obtain chaotic random numbers satisfying a chaotic dynamical system expressed by X(n+1)=F(X(n)) includes an optical signal splitting device for splitting light from a light source into a predetermined number of beams with identical optical power; an optical chaotic signal generating device comprising the same number of interferometers as the beams, each having a pair of optical paths for receiving the beams from the optical signal splitting device, splitting each of the beams, interfering the splitted beams and outputting optical chaotic signals; optical path length difference data memory device for memorizing data on a difference between the lengths of the pair of optical paths at portions thereof between splitting and interfering; optical output signal measuring device for measuring optical power of the optical chaotic signals output from the interferometers as chaotic random numbers; and an optical output signal memory device for m
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: July 17, 2001
    Assignee: Communications Research Laboratory Ministry of Posts and Telecommunications
    Inventors: Ken Umeno, Kenichi Kitayama
  • Patent number: 6246295
    Abstract: A planar radiating oscillator apparatus for micro- and milliwaves includes a pair of conductor patches disposed with their pointed portions in proximity and their far edges on opposite sides, a high-frequency transistor disposed between and connected to the conductor patches, a conductor planar surface disposed under and parallel to the fan-shaped conductor patches from which it is separated by a distance equal to between one-fifteenth and one-fifth the generated wavelength therefrom, and at least one direct current power source connected to the conductor patches and having a ground potential in common with a source potential of the high-frequency transistor.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: June 12, 2001
    Assignees: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventors: Toshiaki Matsui, Masami Murata
  • Patent number: 6215890
    Abstract: A hand gesture recognizing device is provided which can correctly recognize hand gestures at high speed without requiring users to be equipped with tools. A gesture of a user is stereoscopically filmed by a photographing device 1 and then stored in an image storage device 2. A feature image extracting device 3 transforms colors of the stereoscopic image data read from the image storage device 2 in accordance with color transformation tables created by a color transformation table creating device 13, and disassembles and outputs the feature image of the user in corresponding channels. A spatial position calculating device 4 calculates spatial positions of feature parts of the user by utilizing parallax of the feature image outputted from the feature image extracting device 4. A region dividing device 5 defines the space around the user with spatial region codes. A hand gesture detecting device 6 detects how the hands of the user move in relation to the spatial region codes.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: April 10, 2001
    Assignees: Matsushita Electric Industrial Co., Ltd., Communications Research Laboratory of Ministry of Posts and Telecommunications
    Inventors: Hideaki Matsuo, Yuji Takata, Terutaka Teshima, Seiji Igi, Shan Lu, Kazuyuki Imagawa
  • Patent number: 6051454
    Abstract: A lower resist film, which is made of PMMA for EB exposure and has a thickness of about 200 nm, is applied onto a substrate, and then an upper resist film to be exposed to i-rays is applied on the lower resist film. Thereafter, a mixed layer, in which the upper and lower resist films are mixed, is formed in the interface between the upper and lower resist films. Next, the upper resist film, except for the head-forming region thereof, is exposed to i-rays and developed, thereby forming an upper-layer opening. And then the mixed layer and a leg-forming region of the lower resist film are exposed to EB and developed, thereby forming a lower-layer opening having an upper part like a taper progressively expanding upward.
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: April 18, 2000
    Assignees: Matsushita Electric Industrial Co., Ltd., Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventors: Yoshiharu Anda, Toshinobu Matsuno, Manabu Yanagihara, Mitsuru Tanabe, Toshiaki Matsui, Nobumitsu Hirose
  • Patent number: 5982245
    Abstract: A radiating oscillator apparatus for micro- and millimeter waves includes paired fan-shaped conductor patches disposed with their pointed portions in proximity and their arcuate portions on opposite sides, at least one high-frequency transistor disposed between and connected to the fan-shaped conductor patches, a conductor planar surface disposed under and parallel to the fan-shaped conductor patches at an interval of between one-fifteenth and one-fifth the generated wavelength therefrom, and a pair of direct current power supplies connected to the fan-shaped conductor patches separately with a common ground potential.
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: November 9, 1999
    Assignee: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventors: Toshiaki Matsui, Masami Murata
  • Patent number: 5581267
    Abstract: A Gaussian-beam antenna invention comprises a transmitting circuit or a receiving circuit, a resonator consisting of a pair of reflecting mirrors, which consist of a spherical mirror and a planar mirror or two spherical mirrors, and a transmission line which transmits a high-frequency signal between the aforesaid transmitting circuit or receiving circuit and the resonator, one reflecting mirror of the resonator having an electromagnetic wave coupling region constituted as a circular partially transparent mirror surface region having its center on the optical axis.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: December 3, 1996
    Assignee: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventors: Toshiaki Matsui, Masahiro Kiyokawa
  • Patent number: 5450040
    Abstract: A Gaussian-beam oscillator for microwave and millimeter wave comprising a negative resistance amplifier circuit which produces and amplifies a high-frequency signal, a resonator consisting of a pair of reflecting mirrors, which consist of a spherical mirror and a planar mirror or two spherical mirrors, and a wave path which transmits the high-frequency signal between said resonator and said negative resistance amplifier circuit, one reflecting mirror of said resonator having an electromagnetic wave coupling region constituted as a circular partially transparent mirror surface region having its center on the optical axis, the other reflecting mirror having a strip element provided at the center of the optical axis and on the rear surface of said strip element having a coupling region for coupling with said wave path, said one reflecting mirror constituting said resonator and having the electromagnetic wave coupling region having a higher reflectance than the reflectance of the other reflecting mirror.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: September 12, 1995
    Assignee: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventors: Toshiaki Matsui, Masahiro Kiyokawa
  • Patent number: 5379110
    Abstract: The surface characteristics with respect to a high-frequency electromagnetic field of a material to be tested are measured by placing opposite a flat mirror material to be tested one of a pair of concave spherical reflection mirrors fabricated in the same way and formed with high-reflectance circular coupling regions, placing the other spherical reflection mirror at a position symmetrical to the one reflection mirror with respect to the flat mirror material as the plane of symmetry, measuring the Q value of the open resonator formed by the one reflection mirror and the flat mirror material, removing the flat mirror material from the optical axis, measuring the Q value of the open resonator formed by the pair of spherical reflection mirrors, calculating the absolute value of the reflectance of the flat mirror material to be tested from the difference between the two measured Q values, and calculating the phase of the reflected wave at the surface of the flat mirror material to be tested from the measured reson
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: January 3, 1995
    Assignee: Communications Research Laboratory, Ministry of Posts and Telecommunications
    Inventors: Toshiaki Matsui, Kenichi Araki
  • Patent number: 5173926
    Abstract: A convolutionally-encoded quadrature frequency-modulation (CQFM) system of the present invention is a digital modulation system in which binary source data is encoded by a convolutional encoder with an encoding rate of r=1/2, quaternarized, and is then fed into a duobinary converter and a mod.4 mapper for subsequent quadrature frequency-modulation with a modulation index of h=1. The system has a soft-decision Viterbi decoder. This decoder has not only a symbol-metric calculator, a state-metric memory, a path-history memory, and ACS circuit, all used in an ordinary Viterbi decoding system, but also a signal location pointer, which is a memory indicating any one of the nominal signal points in a two-dimensional signal space and being updated in response to the selection of higher-likelihood by the ACS circuit.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: December 22, 1992
    Assignees: Communications Research Laboratory, Ministry of Posts and Telecommunications, Small Power Communication System Research Laboratories, Co., Ltd.
    Inventor: Ken Iwasaki
  • Patent number: 5109164
    Abstract: A superconducting weak link device includes a plurality of interconnected small superconducting regions and a plurality of conductive bridges which connect adjacent the small superconducting regions in which the length of the bridges is in the range from 1 to 5.31 times the coherence length.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: April 28, 1992
    Assignee: Communications Research Laboratory Ministry of Posts and Telecommunications
    Inventor: Toshiaki Matsui
  • Patent number: 5036330
    Abstract: A ranging system using the correlation between two spread spectrum wave signals includes an antenna for receiving from a single radio source two spread spectrum modulated signals simultaneously transmitted in the same code on carrier waves of different frequency, a multiplier for multiplying the received signals by each other to generate two continuous signals of frequencies respectively equal to the difference and the sum of the carrier waves of the spread spectrum signals, and a data processing computer for measuring the phases of the two continuous signals with reference to a reference clock at the receiving station so as to remove the ambiguity at the time of range measurement.
    Type: Grant
    Filed: March 26, 1990
    Date of Patent: July 30, 1991
    Assignee: Communications Research Laboratory Ministry of Post and Telecommunications
    Inventors: Michito Imae, Chihiro Miki