WIRELESS TRANSMITTER/RECEIVER, WIRELESS COMMUNICATION DEVICE, AND WIRELESS COMMUNICATION SYSTEM
First Claim
1. A wireless transmitter/receiver, comprising:
- a local oscillator which oscillates at a predetermined local oscillation frequency;
a mixer for mixing a local oscillation signal having the local oscillation frequency outputted from an output terminal of the local oscillator and a radio signal received by an antenna;
a modulation circuit for modulating the local oscillation signal to generate a radio signal; and
a transmission/reception switching unit which selectively switches over between a reception state in which the output terminal of the local oscillator is connected to the mixer and a transmission state in which the output terminal is connected to the antenna without passing through the mixer,wherein the local oscillator includes;
a reference oscillation unit which oscillates at a predetermined reference oscillation frequency lower than the local oscillation frequency;
a first frequency conversion unit and a second frequency conversion unit which convert a reference oscillation signal having the reference oscillation frequency outputted from an output terminal of the reference oscillation unit into the local oscillation signal;
a first switching unit which selectively switches over between a first input state in which the output terminal of the reference oscillation unit is connected to an input terminal of the first frequency conversion unit and a second input state in which the output terminal of the reference oscillation unit is connected to an input terminal of the second frequency conversion unit; and
a second switching unit which selectively switches over between a first output state in which the output terminal of the local oscillator is connected to the output terminal of the first frequency conversion unit and a second output state in which the output terminal of the local oscillator is connected to an output terminal of the second frequency conversion unit, while cooperating with switching operation of the first switching unit, andwherein the second frequency conversion unit includes a voltage controlled oscillator, a phase comparator, a divider, a loop filter, a phase locked loop circuit having a charge pump, and the first frequency conversion unit includes a frequency multiplying circuit having power consumption smaller than that of the phase locked loop circuit.
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Accused Products
Abstract
Disclosed is a wireless transmitter/receiver provided with: a local oscillator which oscillates at a predetermined local oscillator frequency; a mixer which mixes a local oscillation signal of the local oscillation frequency outputted from an output terminal of the local oscillator and a radio signal received by an antenna; a modulation circuit which modulates the local oscillator signal and generates a radio signal; and a transmission/reception switching unit which selectively switches over between a reception state in which the output terminal of the local oscillator is connected to the mixer and a transmission state in which the output terminal is connected to the antenna without passing through the mixer.
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Citations
23 Claims
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1. A wireless transmitter/receiver, comprising:
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a local oscillator which oscillates at a predetermined local oscillation frequency; a mixer for mixing a local oscillation signal having the local oscillation frequency outputted from an output terminal of the local oscillator and a radio signal received by an antenna; a modulation circuit for modulating the local oscillation signal to generate a radio signal; and a transmission/reception switching unit which selectively switches over between a reception state in which the output terminal of the local oscillator is connected to the mixer and a transmission state in which the output terminal is connected to the antenna without passing through the mixer, wherein the local oscillator includes; a reference oscillation unit which oscillates at a predetermined reference oscillation frequency lower than the local oscillation frequency; a first frequency conversion unit and a second frequency conversion unit which convert a reference oscillation signal having the reference oscillation frequency outputted from an output terminal of the reference oscillation unit into the local oscillation signal; a first switching unit which selectively switches over between a first input state in which the output terminal of the reference oscillation unit is connected to an input terminal of the first frequency conversion unit and a second input state in which the output terminal of the reference oscillation unit is connected to an input terminal of the second frequency conversion unit; and a second switching unit which selectively switches over between a first output state in which the output terminal of the local oscillator is connected to the output terminal of the first frequency conversion unit and a second output state in which the output terminal of the local oscillator is connected to an output terminal of the second frequency conversion unit, while cooperating with switching operation of the first switching unit, and wherein the second frequency conversion unit includes a voltage controlled oscillator, a phase comparator, a divider, a loop filter, a phase locked loop circuit having a charge pump, and the first frequency conversion unit includes a frequency multiplying circuit having power consumption smaller than that of the phase locked loop circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A wireless communication system for transmitting and receiving a radio signal by a radio wave between multiple wireless stations, each of the wireless stations comprising:
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a wireless transmission/reception unit which transmits and receives the radio signal; a radio level measuring unit which measures a received signal strength of the radio signal received by the wireless transmission/reception unit; a timer which outputs a start-up signal whenever a predetermined intermittent reception time is lapsed; and an operation controller which analyzes the reception signal received by the wireless transmission/reception unit to obtain information related to the wireless transmission/reception unit itself, wherein the wireless transmission/reception unit autonomously executes an operation of receiving the radio signal based on an operation command set by the operation controller, and the radio level measuring unit autonomously executes an operation of measuring the received signal strength of the radio signal received by the wireless transmission/reception unit based on an operation command set by the operation controller, wherein the operation controller sets an operation command in the wireless transmission/reception unit and the radio level measuring unit when the operation controller in a sleep state is activated by the start-up signal from the timer, and shifts to the sleep state until the measuring of the received signal strength by the radio level measuring is completed, and wherein, when the measurement result of the received signal strength by the radio level measuring unit is equal to or greater than a predetermined reference value, the wireless transmission/reception unit continuously performs a reception operation and the operation controller analyzes the reception signal; and
, when the measurement result is smaller than the reference value, the wireless transmission/reception unit stops the reception operation. - View Dependent Claims (14, 15, 16, 17)
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18. A wireless communication device, comprising:
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a wireless transmission/reception unit which processes a radio signal received by an antenna to convert it into a bit stream of a pulse signal; and an operation controller which obtains information included in the radio signal from the bit stream outputted from the wireless transmission/reception unit, wherein a communications frame of the radio signal includes a synchronization bit stream for bit synchronization, a frame synchronization bit stream for frame synchronization, and data corresponding to the information, wherein the wireless transmission/reception unit includes; a demodulation unit which demodulates the radio signal into a demodulation signal formed of a bit stream of a pulse signal; a frame synchronization detection unit which detects the frame synchronization bit stream from the bit stream of the demodulation signal and outputs a frame synchronization detection signal; a reception data buffer which temporarily accumulates the demodulation signal outputted from the demodulation unit when the frame synchronization detection signal is outputted; and a command processing unit for outputting the reception data accumulated in the reception data buffer to the operation controller when a reception data output command is received from the operation controller, wherein the operation controller includes; an interface unit which communicates a signal with the wireless transmission/reception unit; and a central processing unit which executes processing of obtaining information included in the radio signal from the bit stream outputted from the wireless transmission/reception unit, or processing of outputting the reception data output command to the wireless transmission/reception unit while the frame synchronization detection signal is being output, and wherein, when the reception data output command is not received until the frame synchronization detection unit stops outputting of the frame synchronization detection signal after starting to output the frame synchronization detection signal, the command processing unit controls the reception data buffer not to output the reception data accumulated therein even if the reception data output command is outputted from the central processing unit of the operation controller before the frame synchronization detection unit starts to output a next frame synchronization detection signal. - View Dependent Claims (19, 20, 21, 22, 23)
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Specification