KR19990010694U - Short-range wireless communication system using common oscillation circuit - Google Patents

Abstract

The present invention is composed of a transmitter having a PLL synthesizer circuit for supplying an oscillation signal for modulating a data signal to be transmitted, and a receiver for sharing the PLL synthesizer circuit for receiving a local oscillation signal for demodulating a received signal. Since only one oscillation circuit composed of PLL synthesizer circuits supplies oscillation signals to the transceiver, the radio communication system can be easily configured to reduce the volume of radio equipment and reduce manufacturing costs, and to provide the oscillation frequency provided to the transceiver. The present invention relates to a single oscillation wireless communication system of a common oscillation circuit method having an effect of enabling multichannel communication.

Description

Short-range wireless communication system using common oscillation circuit

The present invention relates to an oscillation circuit of a short-range wireless communication system, in particular, the transmitter and the receiver are common oscillations in the field of the transceiver of the radio equipment for radio control, the transceiver of the radio equipment for wireless communication in the premises, and the transceiver of the radio equipment for data transmission. The present invention relates to a short-range wireless communication system of a common oscillation circuit method that simplifies a wireless communication system by using a circuit.

In the short communication method, the communication with the other station alternates with each other and uses the same frequency as the other station. If the station is transmitting, the reception is stopped, and if the station is receiving, the transmission is stopped.

In the conventional short-range wireless system as shown in FIG. 1, a transmitter comprising a local oscillator 19, a power amplifier 12, and an antenna 11, an RF amplifier 13, a mixer 14, The data signal to be transmitted by the local oscillator 20 and the receiver including the FM demodulator 18 is modulated using the oscillation signal of the local oscillator 19 and amplified by the power amplifier 12 and then the antenna 11. The received signal transmitted to the air through the antenna and introduced through the antenna 11 is amplified by the RF amplifier 13 and input to the mixing unit together with the oscillation signal of the local oscillator 20 to be a signal of an intermediate frequency band.

In this case, since the signal of the intermediate frequency band is demodulated by the FM demodulator 18 and the received signal is output, the oscillation circuit must be provided in each transmitting and receiving unit, and the volume of the local oscillation circuit is increased because the crystal oscillation method is used to obtain the oscillation signal. There is a problem that becomes large.

On the other hand, as shown in FIG. 2, in the conventional short-range wireless communication system using a PLL synthesizer circuit as an oscillator circuit, a PLL synthesizer circuit 30 for supplying an oscillation signal used when modulating a data signal to be transmitted and a power amplifier ( A transmitter having 22); The receiver 21 includes an antenna 21, an RF amplifier 23, a mixer 24, a PLL synthesizer circuit 40 for supplying a receiver oscillation signal, and a demodulator 28.

The data signal to be transmitted is modulated by receiving the oscillation signal from the PLL synthesizer of the transmitter and then amplified by the power amplifier 22 and transmitted to the air through the antenna 21. The signal received through the antenna 21 is an amplifier ( After the amplification at 23), the PLL synthesizer circuit 41 is inputted to the mixer 24 together with the oscillation signal of the PLL synthesizer circuit 41 to generate a signal of the intermediate frequency band, and the signal of the intermediate frequency band is demodulated by the FM demodulator 28 to obtain a data signal.

At this time, the PLL synthesizer circuit is provided in each of the transceivers, and since the crystal oscillators 31 and 41 are used for each of the PLL synthesizer circuits, there is a problem that the volume of the local oscillator circuit is increased and the manufacturing cost is increased.

The present invention has been devised to solve the above problems, and consists of a single oscillator circuit using only one PLL synthesizer circuit and a common oscillation circuit system capable of supplying oscillating signals of different frequencies to the transceiver. It is an object of the present invention to provide a wireless communication system.

1 is a diagram illustrating a short-range wireless communication system as a first embodiment of the prior art.

if,

2 is a diagram illustrating a short-range wireless communication system as a second embodiment of the prior art;

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Figure 3 is a single radio wireless communication system of the common oscillation circuit method according to the present invention

Expressed drawing.

Explanation of symbols for main parts of the drawings

5: voltage controlled oscillator 6: low pass filter

7: phase comparator 8: FM demodulator

9: crystal oscillator 10: PLL synthesizer circuit

In a single oscillation wireless communication system using a common oscillation circuit according to the present invention, a transmitter having a PLL synthesizer circuit for supplying an oscillation signal for modulating a data signal to be transmitted and a local oscillation signal for demodulating a received signal are provided. It consists of a receiver which uses the said PLL synthesizer circuit in common.

The transmitter further includes a power amplifier for amplifying the modulated data signal; The receiver includes an RF amplifier for amplifying a signal introduced through an antenna, a mixer for mixing an output signal of the RF amplifier and a local oscillation signal from the PLL synthesizer circuit to make an intermediate frequency, and generated by the mixer. Demodulation unit for extracting only the data signal to be received from the intermediate frequency.

In addition, the demodulator comprises a frequency demodulator.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 3, the single oscillation wireless communication system of the common oscillation circuit system according to the present invention includes a PLL synthesizer circuit including a voltage controlled oscillator 5 to obtain an oscillation signal necessary for modulating a data signal to be transmitted ( 10), a transmitter including a power amplifier (2) for amplifying the modulated data signal, and an antenna (1) for transmitting the output signal of the power amplifier (2) in the air;

An RF amplifier 3 for amplifying the signal introduced into the antenna 1, a PLL synthesizer circuit 10 commonly used to obtain a local oscillation signal for demodulating the received signal, and the RF amplifier ( A mixing unit 4 which receives an oscillation signal spaced apart from the output signal of 3) and the oscillation frequency used in the transmission unit from the PLL synthesizer circuit 10 and outputs an intermediate frequency, and only a predetermined data signal from the intermediate frequency. It is composed of a receiver including an FM demodulator (FREQUENCY DEMODULATION) 8 to extract.

The PLL synthesizer circuit 10 receives a voltage controlled oscillator 5 capable of supplying different oscillation frequencies through a plurality of channels and a reference frequency from a crystal oscillator 9 and receives an oscillation signal of the voltage controlled oscillator 5. And a low pass filter 6 for passing only a predetermined signal among the output signals of the phase comparator 7 for synchronizing the phases.

The voltage controlled oscillator 5 in the PLL synthesizer circuit 10 may provide a plurality of frequency channels spaced apart from each other, and the oscillation frequency supplied by the PLL synthesizer circuit 10 to the transmitter and the oscillation frequency supplied to the receiver are different from each other. Since the frequency channel is used, the transceiver receives different oscillation frequencies from each other.

The difference value of the oscillation frequency supplied to the transceiver is the same as the intermediate frequency generated by the mixer of the receiver. Since the center frequency is used at about 450KHz, the frequency difference of the oscillation signal of the transceiver is about 450Khz. Therefore, in the case of the short-term communication method, the oscillation circuit of the transmitter / receiver may be commonly configured by using a single PLL synthesizer circuit.

The present invention is not limited to the above-described embodiment, and various modifications are possible by those skilled in the art within the scope of the appended utility model registration claims. For example, if the FM demodulator is configured with an AM AMPLITUDE MODULATION DETECTION unit, the FM demodulator can also be used for the AM system.

According to the present invention, since only one oscillation circuit composed of a PLL synthesizer circuit supplies an oscillation signal to the transceiver, the wireless communication system can be easily configured, thereby reducing the volume of the radio and reducing the manufacturing cost. By differentiating the oscillation frequency provided to the multi-channel communication is possible to effect.

Claims (3)

A transmitter having a PLL synthesizer circuit for supplying an oscillation signal for modulating a data signal to be transmitted, and a receiver for sharing the PLL synthesizer circuit for receiving a local oscillation signal for demodulating a received signal. Short wireless communication system of oscillation circuit method. The method of claim 1, The transmitter includes a power amplifier for amplifying the modulated data signal, The receiver includes an RF amplifier for amplifying a signal introduced through an antenna, a mixer for mixing an output signal of the RF amplifier and a local oscillation signal from the PLL synthesizer circuit to make an intermediate frequency, and the output from the mixer. A single mode wireless communication system of a common oscillation circuit method, characterized in that the demodulation unit for extracting only the data signal to be received from the intermediate frequency. The method of claim 2, The demodulation unit is a simple oscillation system of the common oscillation circuit method, characterized in that consisting of a frequency demodulation unit.