Patents by Inventor Tomoyuki Ohya

Tomoyuki Ohya 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: 7406410
    Abstract: A decoding apparatus is provided. The decoding apparatus has a first decoding part for decoding a code word obtained by encoding an input signal using a Code-Excited Linear Prediction encoding method. A second decoding part decodes a code word obtained by encoding a signal with an encoding method other than the Code-Excited Linear Prediction encoding method. A rising-transition detection and notification part has a detection part that detects the existence of a rising-transition of amplitude of the input signal based on time variation of a gain of excitation vectors obtained by the first decoding part, and a notification part that notifies the second decoding part that the rising-transition of the amplitude exists.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: July 29, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Kei Kikuiri, Nobuhiko Naka, Tomoyuki Ohya
  • Patent number: 7363231
    Abstract: A coding device capable of improving the coding efficiency and a decoding device for decoding a code sequence generated by the coding device are provided. In the coding device, for each of the possible block combinations obtained when dividing a frame, a coding unit encodes each block in the frame block by block at different bit rates, and at the same time, the coding unit decodes the resultant code sequences related to the frame. A calculation unit calculates the error powers of the decoded signals and the input signal. A determination unit selects a code sequence that makes the average bit rate in coding the frame not higher than a specified value and the corresponding error power a minimum. This selected code sequence is output.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: April 22, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Kei Kikuiri, Nobuhiko Naka, Tomoyuki Ohya
  • Publication number: 20080032684
    Abstract: A radio communication control device includes a radio parameter update determination portion, a transmission power value change portion and a radio parameter update portion. The radio parameter update determination portion determines whether or not to update a radio parameter relating to at least one of a communication frequency and transmission power to a new radio parameter. The transmission power value change portion performs a transmission power change process to change a transmission power value during data transmission to a radio communication station to a smaller value in stages at predetermined intervals when the radio parameter update determination portion determines to update the radio parameter to the new radio parameter. A radio parameter update portion updates the radio parameter to the new radio parameter when the transmission power value change portion changes the transmission power value to a preset lower limit or less.
    Type: Application
    Filed: August 2, 2007
    Publication date: February 7, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Kengo Yagyu, Akira Ishii, Shinichi Mori, Takatoshi Sugiyama, Tomoyuki Ohya
  • Publication number: 20070218914
    Abstract: A wireless communications system is disclosed. The wireless communications system includes a base station unit that is provided in a predetermined area and that is configured to perform wireless communications with at least one mobile station; and at least one measurement unit that is provided in the predetermined area and that is configured to communicate with the base station unit. The measurement unit includes: a unit configured to receive at least a common control channel transmitted from the base station unit; a unit configured to measure a wireless channel status; and a unit configured to report a measurement result to the base station unit. In the wireless communications system, the base station unit adjusts a downlink wireless parameter according to the measurement result reported from the measurement unit.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 20, 2007
    Applicant: NTT DoCoMo, Inc.
    Inventors: Shinichi Mori, Tomoyuki Ohya, Takatoshi Sugiyama
  • Publication number: 20060236159
    Abstract: To provide a data transmitter-receiver bidirectional transmitting system, and data transmitting-receiving method capable of reducing influences of a transmission delay when performing bidirectional communication with an other-communication-party apparatus in an environment in which various states are dynamically changed depending on time. A data obtaining portion 11 of a terminal 10 obtains positional directional information D(Tn) and a time information obtaining portion 12 obtains time information Tn. The terminal 10 stores D(Tn) and Tn in a memory portion 13 and a transmitting portion 15 transmits D(Tn) and Tn to a server 20. A data generating portion 21 of the server 20 generates stereophonic data S(Tn) by using D(Tn), a time information copying portion 22 copies Tn, a transmitting portion 24 transmits S(Tn) and Tn to the terminal 10.
    Type: Application
    Filed: March 10, 2006
    Publication date: October 19, 2006
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yasuyo Yasuda, Nobuhiko Naka, Tomoyuki Ohya, Toshio Miki
  • Patent number: 6952712
    Abstract: A content distribution system includes plurality of cache server apparatus configured to obtain content from a distribution apparatus, and to store the content temporarily; a location information data storage unit configured to store location information data, which indicates location information of each cache server apparatus; a description data storage unit configured to store at least one item of description data, which includes the location information of a distribution apparatus; a converter configured to convert the location information of a distribution apparatus storing a requested content, which is included in description data, into location information of a specified cache server apparatus, by referring to the location information data; and a reception terminal apparatus configured to obtain the description data converted by the converter, and to receive the requested content from the specified cache server apparatus.
    Type: Grant
    Filed: November 29, 2002
    Date of Patent: October 4, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takeshi Yoshimura, Yoshifumi Yonemoto, Minoru Etoh, Tomoyuki Ohya
  • Publication number: 20050185585
    Abstract: A data receiving apparatus has a unidirectional channel receiver for receiving segmental data forming an electronic file, through a unidirectional channel; a file assembler for restoring the electronic file, based on the segmental data received by the unidirectional channel receiver; a channel information memory for acquiring location information for specifying a location of the electronic file; and a bidirectional channel transmitter/receiver for establishing a bidirectional channel when there arises a need for retransmission of the electronic file, for sending a request for transmission of the electronic file to a data transmitting device specified by the location information, through the bidirectional channel, and for receiving the electronic file through the bidirectional channel.
    Type: Application
    Filed: January 14, 2005
    Publication date: August 25, 2005
    Applicant: NTT DoCoMo, Inc
    Inventors: Takeshi Yoshimura, Tomoyuki Ohya, Hidetoshi Ueno
  • Publication number: 20050171769
    Abstract: A voice activity detection apparatus enabling the decision on active interval accurately regardless of time elapse is sought. Apparatus 10 comprises autocorrelation calculating unit 11 calculating autocorrelation value of input signal, delay calculating unit 12 calculating delay for calculated autocorrelation value becoming maximum, noise deciding unit 13 deciding whether input signal is noise or not based on calculated delay, noise estimating unit 14 estimating noise from input signal, activity deciding unit 15 performing activity decision regarding input signal based on result of decision by noise deciding unit 13, noise estimated by noise estimating unit 14, and input signal, and a sound interval detecting unit 16 counting time duration of active interval based on decision result by deciding unit 15. In case of time duration of active interval reaches a predetermined period or more, noise estimating unit 14 changes noise estimating method such that input signal is likely decided as active.
    Type: Application
    Filed: December 23, 2004
    Publication date: August 4, 2005
    Applicant: NTT DoCoMo, Inc.
    Inventors: Nobuhiko Naka, Tomoyuki Ohya
  • Publication number: 20050154583
    Abstract: It is provided a voice activity decision apparatus capable of accurately performing the decision on the state being associated with a sound interval or a silence interval also in terms of the input signal having many aperiodic components and/or plural mixed different periodic components. The apparatus 1 comprises: an autocorrelation calculating unit 11 for calculating autocorrelation values of an input signal; a delay calculating unit 12 for calculating plural delays at which autocorrelation values calculated by the autocorrelation calculating unit 11 become maximums; a noise deciding unit 13 for deciding whether the input signal is a noise or not based on the plurality of delays calculated by the delay calculating unit 12; and an activity decision unit 14 for performing the activity decision in terms of the input signal based on results of decision by the noise deciding unit 13 and the input signal.
    Type: Application
    Filed: December 23, 2004
    Publication date: July 14, 2005
    Inventors: Nobuhiko Naka, Tomoyuki Ohya
  • Publication number: 20050075872
    Abstract: The present invention intends to render quantization noise virtually imperceptible for a user and to prevent reduction in frequency resolution and reduction in encoding efficiency.
    Type: Application
    Filed: December 25, 2002
    Publication date: April 7, 2005
    Inventors: Kei Kikuiri, Nobuhiko Naka, Tomoyuki Ohya
  • Publication number: 20040131061
    Abstract: A packet communication terminal is provided without delay in packet communication between the packet communication terminal moving between different networks, and a correspondent packet communication terminal. The packet communication terminal comprises network address acquiring part, network address storage, network address notifying part, and packet receiver. When there exist a plurality of networks to which the packet communication terminal can be connected, the network address acquiring part acquires a plurality of network addresses from the respective networks. The network address storage stores the plurality of network addresses. The network address notifying part notifies the correspondent packet communication terminal of the plurality of network addresses. The packet receiver receives packets generated from identical data and sent from the correspondent packet communication terminal to the respective network addresses.
    Type: Application
    Filed: September 22, 2003
    Publication date: July 8, 2004
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hosei Matsuoka, Takeshi Yoshimura, Tomoyuki Ohya
  • Publication number: 20040098267
    Abstract: A coding device capable of improving the coding efficiency and a decoding device for decoding a code sequence generated by the coding device are provided. In the coding device., for each of the possible block combinations obtained when dividing a frame, a coding unit encodes each block in the frame block by block at different bit rates, and at the same time, the coding unit decodes the resultant code sequences related to the frame. A calculation unit calculates the error powers of the decoded signals and the input signal. A determination unit selects a code sequence that makes the average bit rate in coding the frame not higher than a specified value and the corresponding error power a minimum. This selected code sequence is output.
    Type: Application
    Filed: August 25, 2003
    Publication date: May 20, 2004
    Applicant: NTT DoCoMo, Inc.
    Inventors: Kei Kikuiri, Nobuhiko Naka, Tomoyuki Ohya
  • Publication number: 20030177011
    Abstract: An interpolation device for judging a state of sounds of a frame at which an error or a loss has occurred in the audio data and carrying out the interpolation according to that state is constructed by an input unit for entering the audio data, a detection unit for detecting the error or the loss of each frame of the audio data, an estimation unit for estimating the interpolation information of the frame at which the error or the loss is detected, and an interpolation unit for interpolating the frame at which the error or the loss is detected, by using the interpolation information estimated for that frame by the estimation unit.
    Type: Application
    Filed: December 16, 2002
    Publication date: September 18, 2003
    Inventors: Yasuyo Yasuda, Tomoyuki Ohya, Sanae Hotani
  • Publication number: 20030154074
    Abstract: A decoding apparatus is provided. The decoding apparatus has a first decoding part for decoding a code word obtained by encoding an input signal using a Code-Excited Linear Prediction encoding method. A second decoding part decodes a code word obtained by encoding a signal with an encoding method other than the Code-Excited Linear Prediction encoding method. A rising-transition detection and notification part has a detection part that detects the existence of a rising-transition of amplitude of the input signal based on time variation of a gain of excitation vectors obtained by the first decoding part, and a notification part that notifies the second decoding part that the rising-transition of the amplitude exists.
    Type: Application
    Filed: February 7, 2003
    Publication date: August 14, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Kei Kikuiri, Nobuhiko Naka, Tomoyuki Ohya
  • Publication number: 20030105925
    Abstract: A content distribution system includes plurality of cache server apparatus configured to obtain content from a distribution apparatus, and to store the content temporarily; a location information data storage unit configured to store location information data, which indicates location information of each cache server apparatus; a description data storage unit configured to store at least one item of description data, which includes the location information of a distribution apparatus; a converter configured to convert the location information of a distribution apparatus storing a requested content, which is included in description data, into location information of a specified cache server apparatus, by referring to the location information data; and a reception terminal apparatus configured to obtain the description data converted by the converter, and to receive the requested content from the specified cache server apparatus.
    Type: Application
    Filed: November 29, 2002
    Publication date: June 5, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takeshi Yoshimura, Yoshifumi Yonemoto, Minoru Etoh, Tomoyuki Ohya
  • Publication number: 20020136162
    Abstract: A congestion state of a transmission path between a transmitting terminal device and a receiving terminal device is analyzed, a transmission state of media packets between the transmitting terminal device and the receiving terminal device is analyzed, and qualities of the media packets to be transmitted by the transmitting terminal device is controlled according to the transmission path congestion state analysis result and the transmission state analysis result.
    Type: Application
    Filed: March 20, 2002
    Publication date: September 26, 2002
    Applicant: NTT DoCoMo, Inc
    Inventors: Takeshi Yoshimura, Toshiro Kawahara, Tomoyuki Ohya, Minoru Etoh
  • Patent number: 6272106
    Abstract: This invention relates to a double talk detecting method suited to be used for an echo canceler, and more particularly to a method for correctly detecting whether or not the double talk is present, even in the case where a speech transmitting level difference between a far-end talker and a near-end talker is comparatively large. What is assumed in the present invention is an echo canceler which can be employed in a telephone line network for transmitting a speech of a far-end talker sent through a digital line and a speech of a near-end talker sent through an analog line. A double talk detecting method applicable to the echo canceler here extracts predetermined analyzed parameters respectively from a first speech signal corresponding to the speech of the far-end talker sent from the echo canceler to a hybrid circuit and the speech of the near-end talker input to the echo canceler through the hybrid circuit. The analyzed parameters herein used include, for example, speech pitches, frequency components, etc.
    Type: Grant
    Filed: March 2, 1998
    Date of Patent: August 7, 2001
    Assignee: NIT Mobile Communications Network, Inc.
    Inventors: Toshiro Kawahara, Tomoyuki Ohya, Masahito Saigusa, Nobuhiko Naka
  • Patent number: 6202188
    Abstract: A data transmission device comprises a transmitter device and a receiver device. The transmitter device divides a data string to be transmitted into an original data string requiring protection against code error and a data string requiring no protection. The transmitter device then carries out an error detection code adding operation and error correction coding at a redundancy code rate of 1/N on the original data string to generate a coded data string. The transmitter device divides the coded data string by N, and outputs the N divided coded data strings and the data string requiring no protection on a communication line under a time division multiplexing control. The receiver device receives the N coded data strings and the data string requiring no protection.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: March 13, 2001
    Assignee: NTT Mobile Communication Network Inc.
    Inventors: Takashi Suzuki, Toshio Miki, Tomoyuki Ohya, Toshiro Kawahara, Satoru Adachi
  • Patent number: 6115425
    Abstract: In order to transmit variable length coded data blocks while reducing data loses caused by code errors, the control circuit 7 makes a group of a plurality of variable length coded data, a fixing length circuit 9 fixes the code length of each of the variable length coded data thus grouped so that the data blocks each have an average code length and then makes a group of the data blocks in that condition, a header outputting circuit 8 prepares a header including information on the grouped data blocks and a synchronization word, and a control circuit 7 controls a switch SWC so that the prepared header and the group of data blocks are output through an output terminal 2. On the decoding side, the data blocks are synchronized/decoded by obtaining the code length of the group of data blocks and the number of the data blocks with reference to the location of the synchronization word in the header and information on the data blocks.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: September 5, 2000
    Assignee: NTT Mobile Communications Networks, Inc.
    Inventors: Satoru Adachi, Tomoyuki Ohya
  • Patent number: 6085158
    Abstract: When errors occur in a received code sequence, an error concealment routine part 130 is actuated and a correct code sequence is generated based on a code sequence received before the errors are detected. A decoding routine part 21' executes a decoding process based on this code sequence and updates the internal state based on the decoded result. Thereafter, when the code errors are recovered, an error recovery routine part 140 is actuated. The error recovery routine part 140 re-estimates a correct code sequence during a time period when the errors are detected, based on a code sequence received before the errors are detected and a code sequence received after no more errors are detected, and generates a second estimated code sequence. The decode process part 21' executes the decoding process based on an internal state information for retaining the second estimated code sequence in an internal state storage part 23', and updates the internal state information based on the decoded result.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: July 4, 2000
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Nobuhiko Naka, Tomoyuki Ohya