Patents by Inventor Masayuki Tomisawa

Masayuki Tomisawa 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: 20060154691
    Abstract: There is provided apparatus for supporting coexistence between a first wireless communication mode and a second wireless communication mode. The apparatus comprises a hardware module and a software module for implementing at least one set of protocols for both communication modes. The software module includes SDR control for enabling switching between the two communication modes. There is also provided a method for switching from the first wireless communication mode to the second wireless communication mode, in a single device, using software defined radio (SDR) control.
    Type: Application
    Filed: January 4, 2006
    Publication date: July 13, 2006
    Inventors: Liang Tang, Chang Xu, Masayuki Tomisawa
  • Publication number: 20060071841
    Abstract: An automatic gain control system,comprises a number of variable gain stages connected in series and a number of sensors, the input of each sensor being connected to a respective output of the variable gain stages. The input of an analogue-to-digital converter is connected to the output of one of the variable gain stages. The input of a control unit is connected to the outputs of the sensors and to the output of the analogue-to-digital converter. The input of a digital-to-analogue converter is connected to the output of the control unit, and the control inputs of each of the variable gain stages is connected to an output of the digital-to-analogue converter. The outputs of the digital-to-analogue converter are used to control the gains of the variable gain stages. Also disclosed is a method for automatically controlling gain in a receiver system.
    Type: Application
    Filed: July 18, 2005
    Publication date: April 6, 2006
    Inventors: Chunhua Yang, Theng Yeo, Masayuki Tomisawa
  • Publication number: 20050278605
    Abstract: An encoder system for encoding a signal according to any number of FEC and/or channel codes comprises a shift register, an array of MOD/XOR stages, and a generator matrix stage for controlling the connections between the shift register and the MOD/XOR stages and altering these connections according to a coding format selected by an encoder selection stage. There is also disclosed a decoder system for decoding a signal encoded according to a number of FEC and/or channel codes comprising a decoding stage, and a generator matrix stage for configuring the decoding stage to a decoding code format to be applied an incoming encoded signal. A decoder selection stage is coupled to the generator matrix stage and selects the decoding code format to be used in the decoding process. The decoder selection stage instructs the generator matrix stage to configure the decoding stage according to the selected decoding code format. There is also disclosed a method for encoding and decoding.
    Type: Application
    Filed: May 19, 2005
    Publication date: December 15, 2005
    Inventors: Chang Xu, Masayuki Tomisawa
  • Publication number: 20050259768
    Abstract: A digital receiver for a burst-mode wireless communication system, such as a Bluetooth system comprises a radio frequency input stage for receiving an input signal and an analogue-to-digital converter for converting the input signal from an analogue signal to a digital signal. A switch is coupled to the analogue-to-digital converter and a first signal processor is coupled to the switch and is arranged to demodulate signals modulated according to a first modulation process, such as a GFSK modulation process. A second signal processor is also coupled to the switch and is arranged to demodulate signals modulated according to a second modulation process, such as ?/4DQPSK modulation process or an 8DPSK modulation process. The switch is arranged to switch the digital signal between the first and second signal processors to recover signals from the first and/or the second modulation process. A method for processing received signals in a burst-mode wireless communication system is also disclosed.
    Type: Application
    Filed: May 16, 2005
    Publication date: November 24, 2005
    Inventors: Chunhua Yang, Theng Yeo, Masayuki Tomisawa
  • Publication number: 20050238121
    Abstract: A system and method for determining a modulation angle of an information bit in a modulated complex signal comprise, in a first stage, determining the inphase component I and the quadrature component Q of the information bit in the modulated complex signal. A division stage determines an absolute ratio of the quadrature component Q to the inphase component I and a second stage determines from the polarity of the inphase and quadrature components the quadrant in which the modulation angle lies. A third stage determines the arctangent of the absolute ratio x of the quadrature component Q to the inphase component I of the transmitted information bit in the modulated signal. A fourth stage determines the modulation angle from the polarity of the inphase and quadrature components and the arctangent of the absolute ratio of the quadrature component Q to the inphase component I of the transmitted information bit in the modulated signal.
    Type: Application
    Filed: March 24, 2005
    Publication date: October 27, 2005
    Inventors: Chang Xu, Masayuki Tomisawa
  • Publication number: 20050190827
    Abstract: A modulation/demodulation apparatus for the encoding and decoding of data, for example in a Bluetooth/WLAN/PHS multi-mode system based on software defined radio comprises an encoding system to encode data according to a plurality of modulation schemes and a decoding system to decode according to the plurality of modulation schemes the encoded data from the encoding system. The encoding system comprises a number of encoding look-up tables which include encoding data for encoding data according to the plurality of modulation schemes, the encoding data for a plurality of the modulation schemes being identical. Similarly, the decoding system comprises a number of decoding look-up tables for decoding the encoded data received from the encoding system. The decoding look-up tables comprise decoding data for decoding data according to the plurality of modulation schemes, the decoding data for a plurality of the modulation schemes being identical. Also disclosed is a method for encoding/decoding data.
    Type: Application
    Filed: February 25, 2005
    Publication date: September 1, 2005
    Inventors: Chang Xu, Masayuki Tomisawa
  • Publication number: 20040247064
    Abstract: A differential detector is disclosed which comprises: a frequency converter (230) arranged to convert an input signal into demodulated baseband signals; samplers (217, 218) arranged to sample said demodulated baseband signals at a sampling frequency to provide sampled signals; a demodulator (231) arranged to demodulate the sampled signals to provide a demodulated signal; and a data slicer (310) arranged to sense an envelope of the demodulated signal to provide an envelope signal and a comparator (224) arranged provide an output signal dependent upon the demodulated signal and the envelope signal.
    Type: Application
    Filed: March 25, 2004
    Publication date: December 9, 2004
    Inventors: Chun Hua Yang, Theng Tee Yeo, Masayuki Tomisawa
  • Publication number: 20040243903
    Abstract: A method of estimating the reliability of decoded message bits in a digital communications system is proposed. Message and tail bits are coded and transmitted across a communications channel. The coded message and tail bits are then decoded and it is determined that the decoded message bits have no error when the decoded tail bits have at least one error.
    Type: Application
    Filed: May 18, 2004
    Publication date: December 2, 2004
    Inventors: Ju Yan Pan, Chang Qing Xu, Masayuki Tomisawa