Patents Examined by Salvatore Gancialosi
  • Patent number: 4943976
    Abstract: A transmitter of a spread spectrum communication system uses a first carrier, a second carrier, a third carrier, a first spread code, and a second spread code. The third carrier is generated by shifting the phase of the first carrier. The second spread code is generated by delaying the first spread code. The first carrier is modulated with an information signal to generate a primary modulation signal. A composite spread spectrum signal is generated by combining and mixing the primary modulation signal, the second carrier, the third carrier, the first spread code, and the second spread code. In a receiver of the system, a separation filter separates the composite spread spectrum signal into a first component and a second component related to the frequency of the first carrier and the frequency of the second carrier respectively. A signal corresponding to the primary modulation signal is demodulated by processing the first and second components of the composite spread spectrum signal.
    Type: Grant
    Filed: September 13, 1989
    Date of Patent: July 24, 1990
    Assignee: Victor Company of Japan, Ltd.
    Inventor: Yukinobu Ishigaki