Patents by Inventor Shousei Yoshida

Shousei Yoshida 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: 6665286
    Abstract: The adaptive receiving block 2k for the k-user generates a receiving signal by the k-th user the m-th path inherent antenna directivity pattern respectively, obtains the k-th user demodulation signal by demodulating and adding for each path simultaneously and outputs weight control error signal e′kl˜e′kM for the purpose of forming directivity pattern for each path. The weight control error synthesis circuit 3 optionally synthesizes weight control error signal e′kl˜e′kM and outputs synthesis weight control error signal e′kl˜e′km. Synthesizing weight control error signals with respect to paths whose arrival directions of multi-path of each user are close, performing a control without synthesizing weight control errors with respect to paths whose arrival directions are apart, increasing the information available for adaptive control and enhancing an adaptive control characteristic and an interference suppression ability.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: December 16, 2003
    Assignee: NEC Corporation
    Inventors: Yasushi Maruta, Shousei Yoshida, Akihisa Ushirokawa
  • Patent number: 6657590
    Abstract: An adaptive antenna reception apparatus includes a plurality of receiving sections and a combining unit. Each of the plurality of receiving sections is provided for a corresponding one of paths. The receiving section generates a path-corresponding demodulation signal for the corresponding path and for a corresponding one of arrays of antennas from path-corresponding despread signals for the corresponding path and for the corresponding array using adaptive weights for the corresponding array. The combining unit combines the path-corresponding demodulation signals over all the arrays and all the paths to generate a demodulation signal.
    Type: Grant
    Filed: June 5, 2002
    Date of Patent: December 2, 2003
    Assignee: NEC Corporation
    Inventor: Shousei Yoshida
  • Publication number: 20030220082
    Abstract: To provide a path timing detection method for an adaptive array antenna system realizing improved path timing detection characteristics and high-quality demodulation results by simple processing. A sliding correlator despreads signals from antennas over a plurality of chip timings. A multibeam former forms a plurality of directional beams from outputs of the sliding correlator. A per-beam delay profile generation means generates a delay profile averaged in a certain cycle with respect to each beam by using the signal sequences of the beams from the multibeam former. A path timing detection means detects path timings one after another from the generated delay profiles with respect to the respective beams by using a minimum selection timing interval centered on a chip timing already selected as a path timing and a minimum selection beam interval centered on the beam having the chip timing already selected.
    Type: Application
    Filed: May 19, 2003
    Publication date: November 27, 2003
    Applicant: NEC CORPORATION
    Inventor: Shousei Yoshida
  • Patent number: 6539226
    Abstract: In soft hand over in a code division multi access mobile radio communication system, interference in a down link caused by transmission from a plurality of base stations for one mobile station, can be restricted. Control of transmission power is performed according to command from the mobile station only in the base station serving as a primary base station which has minimum propagation loss with the mobile station during soft hand over, and the base stations other than the primary base station perform transmission with restricting output. In comparison with the transmission power control performed by the conventional plural base station transmission, interference for the peripheral mobile station can be reduced to achieve higher down link capacity.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: March 25, 2003
    Assignee: NEC Corporation
    Inventors: Hiroshi Furukawa, Kojiro Hamabe, Shousei Yoshida
  • Patent number: 6509872
    Abstract: An adaptive antenna receiving apparatus includes (a) a plurality of antennas, (b) a plurality of adaptive receivers each of which receives signals received in the antennas, in an adaptive antenna pattern in an order in which the signals arrived at the antennas, (c) a plurality of initial receipt weight calculators each of which calculates an initial antenna pattern for each of the signals, and outputs the thus calculated initial antenna pattern to each of the adaptive receivers, (d) an adder which adds output signals transmitted from each of the adaptive receivers, to one another, and (e) a judge which symbol-judges an output signal transmitted from the adder, and transmits an output signal to each of the adaptive receivers.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: January 21, 2003
    Assignee: NEC Corporation
    Inventors: Naoto Ishii, Shousei Yoshida, Akihisa Ushirokawa
  • Publication number: 20020193115
    Abstract: In soft hand over in a code division multi access mobile radio communication system, interference in a down link caused by transmission from a plurality of base stations for one mobile station, can be restricted. Control of transmission power is performed according to command from the mobile station only in the base station serving as a primary base station which has minimum propagation loss with the mobile station during soft hand over, and the base stations other than the primary base station perform transmission with restricting output. In comparison with the transmission power control performed by the conventional plural base station transmission, interference for the peripheral mobile station can be reduced to achieve higher down link capacity.
    Type: Application
    Filed: August 6, 2002
    Publication date: December 19, 2002
    Inventors: Hiroshi Furukawa, Kojiro Hamabe, Shousei Yoshida
  • Publication number: 20020190901
    Abstract: An adaptive antenna reception apparatus includes a plurality of receiving sections and a combining unit. Each of the plurality of receiving sections is provided for a corresponding one of paths. The receiving section generates a path-corresponding demodulation signal for the corresponding path and for a corresponding one of arrays of antennas from path-corresponding despread signals for the corresponding path and for the corresponding array using adaptive weights for the corresponding array. The combining unit combines the path-corresponding demodulation signals over all the arrays and all the paths to generate a demodulation signal.
    Type: Application
    Filed: June 5, 2002
    Publication date: December 19, 2002
    Applicant: NEC Corporation
    Inventor: Shousei Yoshida
  • Publication number: 20020190900
    Abstract: In an adaptive array antenna receiving apparatus, signal to interference ratio (SIR) measuring units are provided in signal processing units, respectively. The SIR measuring units measure signal to interference ratios of existing fingers to supply the measured results for an antenna weight succession processing unit. The antenna weight succession processing unit selects one of the existing fingers on the basis of the measured results. The antenna weight succession processing unit extracts antenna weights from one of the signal processing units that corresponds to the selected finger. The antenna weight succession processing unit supplies the extracted antenna weights to a newly assigned finger or one of the existing fingers that path timing is greatly changed.
    Type: Application
    Filed: May 10, 2002
    Publication date: December 19, 2002
    Applicant: NEC CORPORATION
    Inventors: Masayuki Kimata, Shousei Yoshida
  • Publication number: 20020191580
    Abstract: A multiuser interference elimination apparatus in which, even in the second and other subsequent stages, adaptive updating of antenna weights can be performed and antenna weights can be generated with accuracy by using interference-canceled received signals. A multiplier performs gain correction by multiplying a symbol replica transmitted from the preceding stage by a coefficient [1−(1−&agr;)m−1], and an antenna signal regeneration section converts the gain-corrected symbol replica into antenna signals. Adders add the antenna signals converted by the antenna signal regeneration section to outputs from despread devices and output the addition results to an antenna weight adaptive updating section. The antenna weight adaptive updating section performs adaptive updating of antenna weights by using the addition results.
    Type: Application
    Filed: June 5, 2002
    Publication date: December 19, 2002
    Applicant: NEC CORPORATION
    Inventors: Naoto Ishii, Shousei Yoshida
  • Publication number: 20020187814
    Abstract: An adaptive antenna reception apparatus includes a multi-beam former (1) provided in common to users, to convert antenna-corresponding spread signals received by antennas of an array antenna into beam-corresponding spread signals. A receiving and demodulating section (2) is provided for one of the users, generates beam-corresponding correlation signals at a path timing from the beam-corresponding spread signals, and generates path signals by weighting the beam-corresponding correlation signals with adaptive weights which are updated adaptively, and produces a demodulation signal for the one user by combining the path signals.
    Type: Application
    Filed: June 5, 2002
    Publication date: December 12, 2002
    Applicant: NEC Corporation
    Inventor: Shousei Yoshida
  • Patent number: 6492958
    Abstract: An adaptive antenna reception apparatus includes a reference signal level determination section, reception level detection sections, and beam formers. The reference signal level determination section determines the level of a reference signal for generating an error signal used for antenna adaptive control on the basis of a reception level of each antenna before beam forming. The reception level detection sections calculate antenna weighting factors for the respective paths on the basis of the multiplex signals received through the respective antennas and the error signal output from the reference signal level determination section. The beam formers receive the received multiplex signals and form antenna directivity beams for the respective paths in accordance with the antenna weighting factors output from the reception level detection sections.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: December 10, 2002
    Assignee: NEC Corporation
    Inventor: Shousei Yoshida
  • Patent number: 6487174
    Abstract: In a transmitting electric power control apparatus, non-linear bias characteristic in S/N measurement is previously obtained by measurement, and a conversion table for realizing this reverse characteristic is created in an S/N measuring circuit 10, and when a measured S/N value is output from the dividing circuit 9, the table conversion circuit 1 receives this S/N value as an input and outputs a corrected S/N value from the above-described conversion table, whereby it is possible to provide the S/N measurement with high accuracy, and this corrected and measured S/N is compared with a target S/N, and a demand for increasing and decreasing transmitting electric power is transmitted to a mobile station 53, and, in the mobile station 53, in accordance with the instruction from the base station 20, the transmitting electric power is determined and a coded information signal is transmitted.
    Type: Grant
    Filed: July 10, 1998
    Date of Patent: November 26, 2002
    Assignee: NEC Corporation
    Inventors: Hironori Mizuguchi, Shousei Yoshida, Akihisa Ushirokawa
  • Publication number: 20020135514
    Abstract: In an adaptive antenna receiving apparatus, a plurality of correlations between adjacent antennas are detected for each path, a fixed beam unique to each path arrival direction of the desired wave is formed on the basis of a vector generated by averaging the detected correlations, and each path is received and combined, or a plurality of correlations between adjacent antennas are detected for each signal sequence despread with a plurality of chip timings, a fixed beam unique to the arrival direction of each signal sequence is formed on the basis of a vector generated by averaging the detected correlations, and a path timing is detected on the basis of a delay profile generated from an output of each signal sequence, or a plurality of correlations between adjacent antennas are detected for each signal sequence despread with a plurality of chip timings, a fixed beam unique to the arrival direction of each signal sequence is formed on the basis of a vector generated by averaging the detected correlations, a path
    Type: Application
    Filed: February 4, 2002
    Publication date: September 26, 2002
    Applicant: NEC CORPORATION
    Inventor: Shousei Yoshida
  • Publication number: 20020094837
    Abstract: A cellular type mobile communication system comprising a plurality of cells, a plurality of base stations disposed in the respective cells, and a mobile station located in the cells. On reception of a control command for a transmission power from the mobile station, each base station increases or decreases the transmission power in response to the control command. In addition, each base station renews the transmission power so that the transmission power after increased or decreased approaches a predetermined reference power.
    Type: Application
    Filed: October 19, 2001
    Publication date: July 18, 2002
    Applicant: NEC Corporation
    Inventors: Kojiro Hamabe, Shousei Yoshida
  • Patent number: 6418320
    Abstract: In a method of controlling transmission power in a mobile station which switches a plurality of base stations from one to another with a hand-off time interposed on switching, an increase of the transmission power is suppressed with reference to reception levels of pilot signals sent from the plurality of the base stations which are divided into a first group of base stations under connection and a second group of base stations under non-connection. Specifically, the transmission power is slowly or gradually increased or kept constant when the reception level of the pilot signal sent from the second group base station exceeds that of the pilot signal sent from the first group base station.
    Type: Grant
    Filed: May 29, 1998
    Date of Patent: July 9, 2002
    Assignee: NEC Corporation
    Inventors: Shousei Yoshida, Akihisa Ushirokawa, Hiroshi Furukawa
  • Publication number: 20020055367
    Abstract: A cellular type mobile communication system comprising a plurality of cells, a plurality of base stations disposed in the respective cells, and a mobile station located in the cells. On reception of a control command for a transmission power from the mobile station, each base station increases or decreases the transmission power in response to the control command. In addition, each base station renews the transmission power so that the transmission power after increased or decreased approaches a predetermined reference power.
    Type: Application
    Filed: January 7, 2002
    Publication date: May 9, 2002
    Inventors: Kojiro Hamabe, Shousei Yoshida
  • Publication number: 20020045432
    Abstract: An adaptive antenna reception apparatus includes a reference signal level determination section, reception level detection sections, and beam formers. The reference signal level determination section determines the level of a reference signal for generating an error signal used for antenna adaptive control on the basis of a reception level of each antenna before beam forming. The reception level detection sections calculate antenna weighting factors for the respective paths on the basis of the multiplex signals received through the respective antennas and the error signal output from the reference signal level determination section. The beam formers receive the received multiplex signals and form antenna directivity beams for the respective paths in accordance with the antenna weighting factors output from the reception level detection sections.
    Type: Application
    Filed: August 24, 2001
    Publication date: April 18, 2002
    Inventor: Shousei Yoshida
  • Patent number: 6373881
    Abstract: A CDMA communication receiver comprises a memory for storing chip samples representing amplitudes of a despreading chip sequence sampled at intervals smaller than chip intervals of the chip sequence. From the memory, sync search and tracking circuitry reads a set of chip samples spaced from each other by the chip intervals and spaced from corresponding chip samples of adjacent sets by the smaller intervals, and detects a match or mismatch between the read chip samples and the incoming data sequence. If they match, it is determined that the read chip samples is a synchronized chip sequence. Otherwise, a next set of chip samples is read from the memory for making a further test between the next set and the incoming data sequence. A despreading filter despreads the incoming data sequence with the synchronized chip sequence.
    Type: Grant
    Filed: July 30, 1998
    Date of Patent: April 16, 2002
    Assignee: NEC Corporation
    Inventors: Hironori Mizuguchi, Shousei Yoshida, Akihisa Ushirokawa
  • Publication number: 20020041253
    Abstract: An adaptive antenna receiving apparatus includes (a) a plurality of antennas, (b) a plurality of adaptive receivers each of which receives signals received in the antennas, in an adaptive antenna pattern in an order in which the signals arrived at the antennas, (c) a plurality of initial receipt weight calculators each of which calculates an initial antenna pattern for each of the signals, and outputs the thus calculated initial antenna pattern to each of the adaptive receivers, (d) an adder which adds output signals transmitted from each of the adaptive receivers, to one another, and (e) a judge which symbol-judges an output signal transmitted from the adder, and transmits an output signal to each of the adaptive receivers.
    Type: Application
    Filed: August 29, 2001
    Publication date: April 11, 2002
    Inventors: Naoto Ishii, Shousei Yoshida, Akihisa Ushirokawa
  • Patent number: 6359864
    Abstract: An FDD/CDMA transmission/reception system includes a CDMA transmitter and a CDMA receiver. The CDMA transmitter includes a plurality of transmission antennas, signal transmission units for transmitting transmission signals weighted by different values to the respective transmission antennas, and pilot signal transmission units for transmitting a plurality of different pilot signals to the respective transmission antennas. The CDMA receiver includes a reception unit for obtaining one received signal from the transmission signals from the plurality of transmission antennas of the CDMA transmitter in consideration of reception quality, and a unit for transmitting antenna control signals corresponding to reception power values of the received pilot signals to the CDMA transmitter.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: March 19, 2002
    Assignee: NEC Corporation
    Inventors: Shousei Yoshida, Akihisa Ushirokawa