Baseband signal communication apparatus
First Claim
1. A baseband signal communication apparatus comprising:
- first transmission means for superposing a subcarrier on one value of a baseband signal consisting of binary values, phase-modulating a first carrier with the baseband signal on which the subcarrier is superposed, and transmitting the baseband signal as a first transmission signal wave;
second transmission means for amplitude-modulating a second carrier with the baseband signal on which the subcarrier is superposed, and transmitting the baseband signal as a second transmission signal wave;
first reception means for receiving the first transmission signal wave, detecting the first transmission signal wave by using a homodyne detector so as to obtain a first demodulated signal, extracting the subcarrier from the first demodulated signal by using a first bandpass filter, and obtaining a first baseband demodulated signal by detecting an envelope of the subcarrier by using a first detector;
second reception means for receiving the second transmission signal, frequency-converting the second transmission signal by using a frequency converter so as to obtain an intermediate frequency signal, detecting an envelope of the intermediate frequency signal by using a second detector so as to obtain a second demodulated signal, extracting the subcarrier from the second demodulated signal by using a second bandpass filter, and detecting an envelope of the subcarrier by using a third detector so as to obtain a second baseband signal demodulated signal; and
comparing means for comparing the first and second baseband demodulated signals, and outputting at least one of the first and second baseband demodulated signals as a demodulated signal of the baseband signal when the first and second baseband demodulated signals coincide with each other.
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Accused Products
Abstract
A baseband signal communication apparatus includes a transmission unit and a reception unit. The transmission unit superposes a subcarrier on one value of a baseband signal consisting of binary values, modulates a carrier with the baseband signal on which the subcarrier is superposed, and transmits the baseband signal as a transmission signal wave. The reception unit demodulates the baseband signal having the subcarrier superposed thereon by using a demodulator upon reception of the transmission signal wave, extracts the subcarrier from the demodulated signal by using a bandpass filter, and demodulates the baseband signal by causing a detector to detect an envelope of the subcarrier.
23 Citations
3 Claims
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1. A baseband signal communication apparatus comprising:
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first transmission means for superposing a subcarrier on one value of a baseband signal consisting of binary values, phase-modulating a first carrier with the baseband signal on which the subcarrier is superposed, and transmitting the baseband signal as a first transmission signal wave; second transmission means for amplitude-modulating a second carrier with the baseband signal on which the subcarrier is superposed, and transmitting the baseband signal as a second transmission signal wave; first reception means for receiving the first transmission signal wave, detecting the first transmission signal wave by using a homodyne detector so as to obtain a first demodulated signal, extracting the subcarrier from the first demodulated signal by using a first bandpass filter, and obtaining a first baseband demodulated signal by detecting an envelope of the subcarrier by using a first detector; second reception means for receiving the second transmission signal, frequency-converting the second transmission signal by using a frequency converter so as to obtain an intermediate frequency signal, detecting an envelope of the intermediate frequency signal by using a second detector so as to obtain a second demodulated signal, extracting the subcarrier from the second demodulated signal by using a second bandpass filter, and detecting an envelope of the subcarrier by using a third detector so as to obtain a second baseband signal demodulated signal; and comparing means for comparing the first and second baseband demodulated signals, and outputting at least one of the first and second baseband demodulated signals as a demodulated signal of the baseband signal when the first and second baseband demodulated signals coincide with each other. - View Dependent Claims (3)
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2. A baseband signal communication apparatus comprising:
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transmission means for superposing a subcarrier on one value of a baseband signal consisting of binary values, phase-modulating a carrier wave with the baseband signal on which the subcarrier is superposed, and transmitting the baseband signal as a transmission signal wave; first reception means for receiving the transmission signal wave, performing homodyne detection of the transmission signal wave by using a homodyne detector so as to obtain a first demodulated signal, extracting the subcarrier from the first demodulated signal by using a first bandpass filter, and detecting an envelope of the subcarrier by using a first detector so as to obtain a first baseband demodulated signal; second reception means for receiving a harmonic wave which is amplitude-modulated by the baseband signal having the subcarrier superposed thereon and radiated upon phase modulation in said transmission means, frequency-converting the harmonic wave by using a frequency converter so as to obtain an intermediate frequency signal, detecting an envelope of the intermediate frequency signal by using a second detector, extracting the subcarrier from the second demodulated signal by using a second bandpass filter, and detecting an envelope of the subcarrier by using a third detector so as to obtain a second baseband demodulated signal; and comparing means for comparing the first and second baseband demodulated signals, and outputting at least one of the first and second baseband demodulated signals as a demodulated signal of the baseband signal when the first and second demodulated signals coincide with each other.
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Specification