Patents by Inventor Seiya Shida

Seiya Shida 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).

  • Frequency-division multiplexed signal transmission system
    Patent number: 4145575
    Abstract: A frequency division multiplexing system is disclosed having a plurality of individual modulators which modulate respective modulating signals onto respective carrier frequencies. The carrier frequencies are selected to have a frequency separation so that when modulated signals are combined, significant parts thereof do not overlap in frequency. The combined modulated signals are filtered by comb filters which suppress portions of the frequency spectra intermediate the significant portions.
    Type: Grant
    Filed: October 20, 1977
    Date of Patent: March 20, 1979
    Assignee: Nippon Electric Co., Ltd.
    Inventors: Seiya Shida, Shigeo Fushimi, Masao Sato