Multi-frequency communication system with an improved diversity scheme
First Claim
1. A multi-frequency communication system comprising:
- a transmitting section including;
modulation means including an oscillator for generating a first carrier and a mixer, for modulating the first carrier with data to be transmitted, thereby to generate a modulated output;
first local oscillation means for generating a first local oscillating signal which is to be used as a second carrier;
first mixer means for mixing the modulated output from said modulation means and the first local oscillating signal generated by said first local oscillation means, thereby to generate waves of different frequencies, including at least an upper side band wave having a frequency which is a sum of the frequencies of the modulated output and the first local oscillating signal and a lower side band wave having a frequency which is a difference between the frequencies of the modulated output and the first local oscillating signal; and
transmitting antenna means for radiating electromagnetic waves into the air, the electromagnetic waves including the waves of different frequencies generated by said first mixer means; and
a receiving section including;
receiving antenna means for receiving the electromagnetic waves including the waves of different frequencies and radiated from said transmitting antenna means;
diversity means for extracting at least one wave of the upper side band wave and the lower side band wave from the waves of different frequencies received by said receiving antenna means;
second local oscillation means for generating a second local oscillating signal equal to the first local oscillating signal;
second mixer means for mixing the at least one wave extracted by said diversity means and the second local oscillating signal generated by said second local oscillation means, thereby to generate an output; and
demodulation means for demodulating the output generated by said second mixer means, thereby to recover the data to be transmitted by the transmitting section.
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Accused Products
Abstract
In a transmitting section, a modulator modulates a first carrier with datao be transmitted, thereby producing a modulated output fm, a local oscillator generates a local oscillating signal to be used as a second carrier fLO, a mixer mixes the modulated output and the local oscillating signal, thereby generating waves of different frequencies. These waves include an upper side band wave fLO +fm and a lower side band wave fLO -fm. A transmitting antenna radiates electromagnetic waves into the air, which includes the waves of different frequencies generated by the mixer. In a receiving section, a receiving antenna receives the electromagnetic waves, a diversity section extracts at least one of the upper side band and lower side band waves fLO +fm, fLO -fm from the waves of different frequencies received by the receiving antenna, a local oscillator generates a local oscillating signal corresponding to the second carrier, a mixer mixes the one wave extracted by the diversity section and the local oscillating signal generated by the local oscillator, thereby generating an output, and a demodulator extracts a signal corresponding to the first carrier, from the output of the mixer, and demodulates the signal thus extracted, thereby outputting data corresponding to the data transmitted from the transmitting section.
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Citations
14 Claims
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1. A multi-frequency communication system comprising:
a transmitting section including; modulation means including an oscillator for generating a first carrier and a mixer, for modulating the first carrier with data to be transmitted, thereby to generate a modulated output; first local oscillation means for generating a first local oscillating signal which is to be used as a second carrier; first mixer means for mixing the modulated output from said modulation means and the first local oscillating signal generated by said first local oscillation means, thereby to generate waves of different frequencies, including at least an upper side band wave having a frequency which is a sum of the frequencies of the modulated output and the first local oscillating signal and a lower side band wave having a frequency which is a difference between the frequencies of the modulated output and the first local oscillating signal; and transmitting antenna means for radiating electromagnetic waves into the air, the electromagnetic waves including the waves of different frequencies generated by said first mixer means; and
a receiving section including;receiving antenna means for receiving the electromagnetic waves including the waves of different frequencies and radiated from said transmitting antenna means; diversity means for extracting at least one wave of the upper side band wave and the lower side band wave from the waves of different frequencies received by said receiving antenna means; second local oscillation means for generating a second local oscillating signal equal to the first local oscillating signal; second mixer means for mixing the at least one wave extracted by said diversity means and the second local oscillating signal generated by said second local oscillation means, thereby to generate an output; and demodulation means for demodulating the output generated by said second mixer means, thereby to recover the data to be transmitted by the transmitting section. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A multi-frequency communication system comprising:
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a transmitting section including; modulation means including an oscillator for generating a first carrier and a mixer, for modulating the first carrier with data to be transmitted, thereby to generate a modulated output; first local oscillation means for generating a first local oscillating signal which is to be used as a second carrier; first mixer means for mixing the modulated output from said modulation means and the first local oscillating signal generated by said first local oscillation means, thereby to generate waves of different frequencies, including at least an upper side band wave having a frequency which is a sum of the frequencies of the modulated output and the first local oscillating signal and a lower side band wave having a frequency which is a difference between the frequencies of the modulated output and the first local oscillating signal; and transmitting antenna means for radiating electromagnetic waves into the air, the electromagnetic waves including the waves of different frequencies generated by said first mixer means; and a receiving section including; receiving antenna means for receiving the electromagnetic waves including the waves of different frequencies and radiated from said transmitting antenna means; diversity means for synthesizing the upper side band wave and the lower side band wave, in phase-state, from the waves of different frequencies received by said receiving antenna means, thereby to generate an output; and demodulation means for demodulating the output generated by said diversity means, thereby to recover the data to be transmitted by the transmitting section. - View Dependent Claims (11, 12)
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13. A method for performing multi-frequency communication, comprising the steps of:
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modulating a first carrier generated by an oscillator with data to be transmitted in a mixer, thereby to generate a modulated output; first generating a first local oscillating signal which is to be used as a second carrier; first mixing the modulated output and the first local oscillating signal, thereby to generate waves of different frequencies, including at least an upper side band wave having a frequency which is a sum of the frequencies of the modulated output and the first local oscillating signal and a lower side band wave having a frequency which is a difference between the frequencies of the modulated output and the first local oscillating signal; radiating electromagnetic waves into the air, the electromagnetic waves including the waves of different frequencies; receiving the electromagnetic waves including the waves of different frequencies; extracting at least one wave of the upper side band wave and the lower side band wave from the waves of different frequencies received by said receiving step; second generating a second local oscillating signal equal to the first local oscillating signal; second mixing the at least one wave extracted by said extracting step and the second local oscillating signal generated, thereby to generate an output; and demodulating the output generated by said second mixing step, thereby to recover the data to be transmitted.
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14. A method for performing multi-frequency communication, comprising the steps of:
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modulating a first carrier generated by an oscillator with data to be transmitted in a mixer, thereby to generate a modulated output; generating a local oscillating signal which is to be used as a second carrier; mixing the modulated output and the local oscillating signal, thereby to generate waves of different frequencies, including at least an upper side band wave having a frequency which is a sum of the frequencies of the modulated output and the local oscillating signal and a lower side band wave having a frequency which is a difference between the frequencies of the modulated output and the local oscillating signal; radiating electromagnetic waves into the air, the electromagnetic waves including the waves of different frequencies; receiving the electromagnetic waves including the waves of different frequencies; synthesizing the upper side band wave and the lower side band wave, in phase state, from the waves of different frequencies received by said receiving step, thereby to generate an output; and demodulating the output generated by said synthesizing step, thereby to recover the data to be transmitted.
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Specification