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Radio receiving apparatus for receiving communication signals of different bandwidths

  • US 6,104,764 A
  • Filed: 12/08/1999
  • Issued: 08/15/2000
  • Est. Priority Date: 03/27/1996
  • Status: Expired due to Fees
First Claim
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1. A radio receiving apparatus for a radio system in which carrier frequencies are channel-positioned at equal frequency intervals or positioned in a manner similar thereto and which employs a quadrature demodulation scheme or a demodulation scheme similar thereto, said radio receiving apparatus comprising:

  • means supplied with a received signal including a signal of a reception-desired channel, for selectively converting, into an intermediate frequency band or a DC-inclusive band, a frequency band including up to approximately 12 channels on each of upper and lower sides of a center frequency that is an upper or lower end of the reception-desired channel or a boundary frequency with an adjacent channel thereof;

    means for sampling the frequency-converted signal at a frequency that is 64-fold a bandwidth of the reception-desired channel or 64-fold of a 1/2 frequency of a channel interval frequency of the radio system;

    means for extracting orthogonal components in a phase domain from the sampled signal;

    means for extracting a signal of four channels including the reception-desired channel from a real-axis signal component and an imaginary-axis signal component of the extracted orthogonal components while rejecting a signal of the other adjacent channels; and

    means for extracting only the signal of the reception-desired channel while rejecting a signal of the other adjacent channels with a sampling frequency set at a frequency that is 16-fold the bandwidth of the reception-desired channel or 16-fold of the 1/2 frequency of the channel interval frequency of the radio system.

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