Transmitter, receiver, and radio communications system and method
First Claim
1. A transmitter comprising a transmitter mixer which produces a first and second radio frequency signals for radio wave transmission by mixing a first and second signals with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal.
1 Assignment
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Accused Products
Abstract
Transmitter and receiver for wireless communications with improved accuracy and stability in radio frequency control. A transmitter mixes an information-carrying signal (first signal) and a non-modulated wave signal (second signal) with a carrier signal, thereby producing a first and second radio frequency signals for radio wave transmission. A receiver mixes those two radio frequency signals to extract the original information signal. While the received radio frequency signals contain some frequency fluctuations and phase noises that have been introduced at the sending end, such unstable components Δf will cancel out at the receiving end.
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Citations
59 Claims
- 1. A transmitter comprising a transmitter mixer which produces a first and second radio frequency signals for radio wave transmission by mixing a first and second signals with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal.
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20. A transmitter comprising a transmitter mixer which produces a first and second radio frequency signals for radio wave transmission by mixing a first and second signals with a carrier signal, the first signal being a baseband signal, the second signal being a non-modulated wave signal.
- 21. A receiver comprising a receiver mixer which mixes a received first and second radio frequency signals to extract a difference frequency signal therefrom, the first and second radio frequency signals having been produced at a sending end by mixing a first signal and a second signal with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal.
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37. A radio communications system, comprising:
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a transmitter comprising a transmitter mixer which produces a first and second radio frequency signals for radio wave transmission by mixing a first and second signals with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal; and
a receiver comprising a receiver mixer which extracts a difference frequency signal from the first and second radio frequency signals by mixing the first and second radio frequency signals that are received from said transmitter.
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45. A method of sending information from a transmitting end to a receiving end through a radio communication channel, comprising the steps of:
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(a) at the transmitting end, sending out a first and second radio frequency signals which are produced by mixing a first and second signals with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal; and
(b) at the receiving end, extracting a difference frequency signal from the first and second radio frequency signals by mixing the first and second radio frequency signals that are received from the transmitting end.
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- 53. A method of sending information, comprising the step of transmitting a first and second radio frequency signals which are produced by mixing a first and second signals with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal.
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58. A method of receiving information, comprising the step of mixing a received first and second radio frequency signals to extract a difference frequency signal therefrom, the first and second radio frequency signals having been produced at a sending end by mixing a first signal and a second signal with a carrier signal, the first signal being modulated with an information signal, the second signal being a non-modulated wave signal.
Specification