Portable transmitter/receiver apparatus with coded data transmission for reduced interference
First Claim
1. A transmitter/receiver apparatus comprising:
- (a) a transmitter including an intermittent signal generator for generating an intermittent signal, said intermittent signal generator comprising an oscillator, a frequency divider for frequency-dividing an oscillation output from said oscillator at predetermined frequency division ratios, a selection gate for selecting a plurality of pulse signals having different periods by using frequency-divided signals from said frequency divider, and an intermittent signal forming circuit for receiving the plurality of pulse signals from said selection gate and outputting intermittent signals whose intervals cyclically change in a predetermined order, said intermittent signal having pulses with different but cyclically repeated intervals, and an intermittent modulator for outputting an intermittently modulated signal, as a radio signal, which is obtained by intermittently modulating a carrier on the basis of the intermittent signal; and
(b) a receiver including a synchronization determining circuit, having a receiving circuit for receiving the radio signal from said transmitter and outputting a demodulated signal, for detecting the demodulated signal and outputting a determining signal, and a synchronization detector for generating an intermittent sync. signal having the same period as that of the intermittent signal from said transmitter, and detecting synchronization operation with respect to the intermittent signal from said transmitter on the basis of the intermittent sync. signal and the determining signal from said synchronization determining circuit, wherein said intermittent signal generator of said transmitter generates intermittent signals having different but cyclically repeated intervals.
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Accused Products
Abstract
A transmitter/receiver apparatus includes a transmitter and a receiver. The transmitter includes an intermittent signal generator and an intermittent modulator. The intermittent signal generator generates an intermittent signal. The intermittent modulator outputs an intermittent modulated signal, as a radio signal, which is obtained by intermittently modulating a carrier on the basis of the intermittent signal. The receiver includes a synchronization determining circuit and a synchronization detector. The synchronization determining circuit has a receiving circuit for receiving the radio signal from the transmitter and outputting a demodulated signal and is designed to detect the presence/absence of the demodulated signal and output a determining signal. The synchronization detector generates an intermittent sync signal having the same period as that of the intermittent signal from the transmitter, and performs a synchronization detecting operation with respect to the intermittent signal from the transmitter on the basis of the intermittent sync signal and the determining signal from the synchronization determining circuit. The intermittent signal generator of the transmitter generates intermittent signals having intervals which cyclically change.
16 Citations
11 Claims
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1. A transmitter/receiver apparatus comprising:
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(a) a transmitter including an intermittent signal generator for generating an intermittent signal, said intermittent signal generator comprising an oscillator, a frequency divider for frequency-dividing an oscillation output from said oscillator at predetermined frequency division ratios, a selection gate for selecting a plurality of pulse signals having different periods by using frequency-divided signals from said frequency divider, and an intermittent signal forming circuit for receiving the plurality of pulse signals from said selection gate and outputting intermittent signals whose intervals cyclically change in a predetermined order, said intermittent signal having pulses with different but cyclically repeated intervals, and an intermittent modulator for outputting an intermittently modulated signal, as a radio signal, which is obtained by intermittently modulating a carrier on the basis of the intermittent signal; and (b) a receiver including a synchronization determining circuit, having a receiving circuit for receiving the radio signal from said transmitter and outputting a demodulated signal, for detecting the demodulated signal and outputting a determining signal, and a synchronization detector for generating an intermittent sync. signal having the same period as that of the intermittent signal from said transmitter, and detecting synchronization operation with respect to the intermittent signal from said transmitter on the basis of the intermittent sync. signal and the determining signal from said synchronization determining circuit, wherein said intermittent signal generator of said transmitter generates intermittent signals having different but cyclically repeated intervals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of detecting initial synchronization of a transmitter/receiver comprises the steps of:
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(a) generating an initializing pulse; (b) resetting a mode switching circuit by the initializing pulse, and outputting a continuous mode signal; (c) detecting a radio signal which is output from a transmitter in response to the continuous mode signal, continuously operating a synchronization determining circuit for outputting a determining signal, and holding a synchronization detector in a reset state; (d) canceling the reset state of said mode switching circuit and stopping output of the continuous mode signal by a first determining signal from said synchronization determining circuit; (e) setting said synchronization determining circuit in an inoperative state and canceling the reset state of said synchronization detector upon stop of the continuous mode signal; (f) starting a cyclic designating operation upon cancellation of the reset state so as to cause said synchronization detector to output a plurality of intermittent sync signals included in one cycle in a predetermined order; (g) operating said synchronization determining circuit in response to the intermittent sync signal; (h) causing said synchronization detector to store an order of synchronization by detecting a second determining signal and an intermittent sync signal synchronized therewith; and (i) causing said synchronization detector and said synchronization determining circuit to start an intermittent synchronization mode in the order of synchronization stored in said synchronization detector. - View Dependent Claims (11)
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Specification