JPH0669831A - Transmitter/receiver - Google Patents

Abstract

PURPOSE:To shorten the time of a response from the reception side corresponding to a call from the transmission side by detecting a calling signal with a first detecting means and enabling communication when a second detecting means detects a prescribed tone signal. CONSTITUTION:A microcomputer 1 and a carrier detection circuit 22 search an idle channel enabling communication, and the micro-computer 1 and a tone oscillator 4 transmit a signal superimposing a tone signal St and a call signal Sc to that idle channel. On the reception side, a first detecting means 14 detects which channel inputs the call signal Sc. Concerning the time of this detection, the channel can be detected in a short time since the frequency of the signal Sc is high. When the means 14 detects the signal Sc, that channel is fixed, and next, the signal St is detected by a second detecting means 15. This signal St is collated with a peculiar tone signal Dt on the reception side and when it is the same signal, communication is enabled. Namely, the signal Sc is coarsely detected, afterwards, the tone signal St is detected and next, it is detected whether those signals are addressed to the user himself or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter / receiver, and more particularly to a transmitter / receiver having a channel control system which enables communication with a specific partner without being aware of a frequency channel.

[0002]

2. Description of the Related Art Recently, among the frequency channels set corresponding to a plurality of frequency bands, an empty channel that can be communicated with is searched for, and when an empty channel is found, the empty channel is used for communication. A transceiver that performs is known.

In the conventional transmitter / receiver, for example, when looking at the transmitting side, a channel is set with a channel setting key on the operation panel, and whether or not there is a carrier in the set channel is checked (squelch chuck). This operation is performed by sequentially updating channels until a channel for which a carrier wave is not output, that is, an empty channel is found.

When a vacant channel is found, the transmitting side transmits one tone signal indicating a specific partner among a plurality of tone signals previously agreed between users. The other transceivers are always on standby and scan each channel for tone signals. Since one tone signal is transmitted from the transmitting side, the other transceivers detect the tone signal in that channel.

Then, it is checked whether the detected tone signal is the same as one's own tone. When it matches with the tone signal, communication with the transmission side becomes possible. On the other hand, if it does not match the tone signal, communication becomes impossible and the standby state is restored. That is, it scans whether or not there is a tone signal on another channel. Here, the tone signal is selected to have a low frequency (50 to 250 Hz) in accordance with the regulations, and usually about 30 types are prepared.

[0006]

However, in the above-mentioned conventional transmitter / receiver, since the tone signal is a signal of a very low frequency, when detecting the tone signal in the standby state, 200 ms or more for each channel. There is a problem that it takes time. Therefore, there is a problem in that it takes a very long time from when the transmitting side issues the tone signal until the response comes from the receiving side, which is inconvenient in operation.

The present invention has been made in view of the above problems, and an object of the present invention is to shorten the time from when the transmitting side makes a call to when the receiving side receives a response, and It is to provide a transceiver that can achieve the above convenience.

[0008]

SUMMARY OF THE INVENTION The present invention detects a transmitted tone signal St and detects the detected tone signal St.
Is a preset tone signal St among a plurality of types of tone signals St, the transmitter / receiver in the communicable state changes the call signal Sc having a frequency higher than the tone signal St to the tone signal St. Call transmission means (microcomputer 1, tone oscillator 4, local oscillator 5, carrier) for transmitting the superposed signal to the empty channel in which communication is possible among frequency channels set corresponding to a plurality of frequency bands. Detection circuit 22),
First detecting means (1 kHz amplifier 14) for detecting the calling signal Sc from the superimposed signal transmitted to the empty channel, and second detecting means for detecting the tone signal St from the superimposed signal transmitted to the empty channel. Detecting means (tone detector 15) and the first detecting means 1
When the calling signal Sc is detected at 4 and the predetermined tone signal St is detected at the second detecting means 15, communication is possible.

[0009]

In the transceiver according to the present invention, when making a call, first, the call transmitting means (microcomputer 1, carrier detection circuit 22) can communicate in the frequency channels set corresponding to a plurality of frequency bands. Find the empty channel that has become. When an empty channel is found, the calling transmission means (microcomputer 1, tone oscillator 4) sends a superposed signal in which the tone signal St and the calling signal Sc are superposed on the empty channel.

On the called side, the first detecting means 14 detects which channel contains the calling signal Sc. This detection time depends on the calling signal Sc
Since the frequency of is relatively high, it can be detected in a very short time unlike the conventional method of detecting the tone signal St and searching for which channel is being called. Then, when the calling signal Sc is detected by the first detecting means 14, it is fixed to that channel, and this time, the second detecting means 15 detects the tone signal St. The detected tone signal St is further collated with the unique tone signal Dt on the called side,
Communication is possible only when the verification results are the same.

That is, by detecting the calling signal Sc, it is possible to roughly detect which channel is being called, and then detect the tone signal St from the channel in which the calling signal Sc is detected to call the channel. Detect if is against you.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a transceiver according to the present invention will be described below with reference to FIG.
2 and FIG. 2.

As shown in FIG. 1, the transceiver according to this embodiment has a transmission system and a reception system, and various controls of the transmission system and the reception system are performed by a microcomputer (hereinafter simply referred to as a microcomputer) 1 It is configured to do.

The transmission system includes a microphone 2 to which voice is input,
Based on the low-frequency amplifier 3 which amplifies the audio signal As from the microphone 2 and supplies it to the transmission line L, and the type signal S from the microcomputer 1, the tone signal St corresponding to the type is oscillated, and the tone signal St is generated. The tone oscillator 4 supplies St to the transmission line L. In particular, in this embodiment, the calling signal Sc of, for example, 1 KHz included in the audio frequency band is supplied from the predetermined terminal of the microcomputer 1 to the transmission line L.

The audio signal A supplied to the transmission line L
s, the tone signal St, and the calling signal Sc are FM-modulated by the local oscillator 5 in the subsequent stage. F from the local oscillator 5
The M-modulated signal Sf is high-frequency amplified by the high-frequency amplifier 6 and transmitted to the space via the transmission terminal φt and the antenna 7.

On the other hand, the reception system outputs a high frequency amplifier 11 for amplifying the FM modulation signal Sf supplied via the antenna 7 and the reception terminal φs, and an FM modulation signal Sf from the high frequency amplifier 11 from the local oscillator 5. FM modulation signal (intermediate frequency signal) S in the intermediate frequency band based on the oscillation frequency
_For the mixer 12 for converting to _if and the intermediate frequency signal S _if ,
IF amplification that performs intermediate frequency amplification, amplitude limitation and FM detection
A detection circuit 13 and a 1 KHz amplifier 14 that amplifies only a signal Sc having a frequency of 1 KHz from the demodulated signal Ss from the IF amplification / detection circuit 13 to extract a calling signal Sc 14
Of the demodulated signal Ss, only the tone signal St is extracted, the tone type data Dt from the microcomputer 1 is compared, and if they are the same, the tone detector 15 outputs the tone detection signal Pt to the microcomputer. Have and. The demodulated signal Ss is output as sound through the low frequency amplifier 16 and the speaker 17.

The local oscillator 5 outputs the signal supplied to the transmission line L to F based on the control signal Tc from the PLL 21.
M-modulate. The output timing of the control signal Tc changes according to the frequency division value data Dn supplied from the microcomputer 1. In the present embodiment, a plurality of usable frequency bands are set as frequency channels, for example, channels 1 to 9 according to the standard, and frequency division value data Dn corresponding to the plurality of frequency channels are stored in the microcomputer 1. It is registered in RAM. Therefore, for example, when the channel 1 is selected, the local oscillator 5 generates the carrier wave having the intermediate frequency of the frequency band corresponding to the channel 1.

On the other hand, a carrier detection circuit 22 for detecting the presence / absence of a carrier wave is connected to the IF amplification / detection circuit 13 of the receiving system. When the carrier wave is present in the received signal, a low level signal (off Signal), when a carrier does not exist, a low level signal (ON signal) is output. The on / off signal (squelch signal) P from the carrier detection circuit 22 is supplied to the microcomputer 1. A voltage detection circuit 24 that detects the voltage V of the battery 23 is connected to the transceiver. The detection signal Sv from the voltage detection circuit 24 is digitally converted by the A / D converter 25 and supplied to the microcomputer 1 as voltage level data Dv.

An input means 26 and a display means 27 are connected to the microcomputer 1. The input unit 26 is composed of various operation buttons. Examples of these operation buttons include a talk button, a power key, a monitor key, a mode selection button, a lamp / battery check /
There are a lock key, a channel setting key, and a tone setting key (tone UP key and tone DOWN key). The display means 27 is composed of, for example, a liquid crystal display, and is adapted to perform lock display, communication state display, battery remaining amount display, channel display and tone display.

Next, the operation of the transceiver according to this embodiment will be described. First, when the battery 23 is inserted into the transceiver, the microcomputer 1 is reset (initialization of data in the RAM, etc.) and then each port is initialized. At this time, after the data group such as operable voltage data registered in the data ROM is stored in the RAM, the battery voltage reduction check is performed. This check is performed in the microcomputer 1 by comparing the voltage level data Dv from the voltage detection circuit 24 with the operable voltage data. When it is determined that the microcomputer can operate, the calling code is sent from the IDROM to the RAM of the microcomputer 1.
Take in.

Next, by pressing the power key, the reception state of channel 1 in the normal communication mode is set. In addition,
There are other tone squelch communication modes and call communication modes as the reception modes. Details of these communication modes will be described later. Then, the power is turned off automatically when any key is pressed last or 6 hours after the last signal is received. of course,
When the power is turned on, if the power key is pressed again, the power turns off.

Next, the channel is set by the channel setting key, the set channel is displayed as a channel display (numeral), and communication in the frequency band corresponding to the channel becomes possible. Then, the setting is performed as follows. That is, each time the channel setting key is pressed, the channel display changes from 1 → 2 → 3 →
… → 8 → 9 → 1 → ... When the channel setting key is held down for 750 ms, the fast forward mode is set.

Next, the communication mode is set as follows. That is, by pressing the mode selection button,
The communication mode is normal communication mode → tone squelch communication mode → call communication mode → normal communication mode → ...
It changes with the display like.

Here, the normal communication mode is a mode in which, at the time of reception, the squelch signal P from the carrier detection circuit 22 of the receiving system determines whether or not the squelch operation is performed. Normally, when no signal is input in the receiving state, a large noise is generated from the speaker 17, but in the present embodiment, the carrier detection circuit 22 detects the presence or absence of a carrier wave, and if there is no carrier wave, the squelch signal P is output. It turns on.

When the squelch signal P is turned on, the squelch circuit provided in the microcomputer 1 operates to change the bias of the low-frequency amplifier 16, thereby lowering the amplification degree of the amplifier 16 and the speaker 17. To make silence. On the contrary, when a carrier wave is present in the received signal and the squelch signal P is turned off, the squelch operation by the squelch circuit in the microcomputer 1 is not performed.

Next, the tone squelch communication mode is a mode in which the squelch operation is not performed only on a signal containing the same tone signal St as the type of the set tone signal St. That is, in the present embodiment, the received tone signal St is compared with the tone signal Dt set in the microcomputer 1 in the tone detector 15, and if the comparison result is the same, the tone detector 15 is In this tone squelch setting mode, the microcomputer 1 searches the on / off state of the squelch signal P and the tone detection signal Pt.
The squelch operation by the squelch circuit in the microcomputer 1 is released only when the squelch signal P is off and the tone detection signal Pt is on.

In the normal communication mode and tone squelch communication mode, when the monitor key is pressed to display the monitor, the microcomputer 1 forcibly cancels the squelch operation by the squelch circuit.

Next, the call communication mode is a mode peculiar to the transceiver according to the present embodiment, and is a mode for automatically searching for a vacant channel and calling the other party by using the tone signal St and the calling signal Sc. . After calling, communication is performed in the same manner as the tone squelch communication mode. This specific operation will be described later.

Next, the tone signal St will be described. A plurality of types of tone signal St are prepared as the type signal S in the microcomputer 1. By pressing the tone UP key and tone DOWN key, an arbitrary type signal S can be obtained. Is set, and the set type signal S is displayed as a tone display (number). At the time of transmission, the type signal S set as above is supplied from the microcomputer 1 to the tone oscillator 4, and the tone signal St based on the type signal S is generated. Further, in the microcomputer 1, the tone type data Dt is read from the RAM using the type signal S as address data and supplied to the tone detector 15 in the receiving system.

The tone display changes as 1 → 2 → 3 → ... → 36 → 37 → 38 → 1 → ... each time the tone UP key is pressed, and each time the tone DOWN key is pressed,
1 → 38 → 37 → 36 → ... → 4 → 3 → 2 → 1 → ... And tone UP key, tone DO
When both WN keys are pressed for 750 ms, the fast forward mode is entered. While the key is being pressed, it fast-forwards in 0.2 second cycles.

Next, the transmission operation in the normal communication mode and the Tonsquelch communication mode will be described.

First, when the talk button is pressed, carrier sense of the set channel is performed, and if no radio wave is emitted, the transmission mode of the channel is set. After the PLL 21 is locked, the regulation ID signal is output and the transmission state is maintained. When the talk button is released, it returns to the reception mode.

That is, the frequency division value data Dn corresponding to the set channel is supplied from the microcomputer 1 to the PLL 21, and the local oscillator 5 outputs the frequency signal corresponding to the channel. Therefore, the signal in that channel is extracted from the mixer 12 of the receiving system. The carrier sense indicates an operation of detecting in the carrier detection circuit 22 whether or not a carrier exists in the signal on the channel, and when there is no carrier, that is, the squelch signal P is on, transmission on the channel is performed. Is possible.

On the contrary, when the carrier wave is detected in the above-mentioned channel and the squelch signal P is off, the microcomputer 1 displays the fact on the display means 27 and the speaker 1
The first BEEP sound is output to 7. In this case, the transmission mode is not entered but the standby state is set. The carrier sense is performed once every 20 ms in the reception state. After the communication starts, carrier sense is not performed until the communication ends.

Next, the receiving operation in the normal communication mode and the Tonsquelch communication mode will be described.

When the squelch signal P is turned on in the receiving state, the squelch operation by the squelch circuit is started. Then, the squelch signal P does not turn off for a certain period of time,
Moreover, if there is no key input, the power save mode is entered. As described above, this power saving operation is an operation performed to save power consumption when there is no radio wave in the receiving state and there is no key input, and the power supply to some circuits is repeatedly turned on and off. . When the squelch signal P is turned "off" by the radio wave being sensed or the monitor key being pressed, the squelch operation by the squelch circuit is canceled and the power save mode is exited. The power save mode is also exited when any key is pressed.

By the way, this transceiver has a communication time limiting function. That is, three minutes after the start of communication, the transmission is stopped and the mode returns to the reception mode even if the talk button is pressed. If the talk button has been pressed from 2 minutes 55 seconds after the start of communication, that effect is displayed on the display means 27 and the second BEEP is output to the speaker 17. After returning to the receiving mode, the display means 27 displays that the mode has returned to the receiving mode, and further outputs the second BEEP sound to the speaker 17.

After that, when the talk button is still pressed, the above display and the output of the second BEEP2 sound are continued during that time. When the talk button is released, the display disappears and the second BEEP2 sound is not output to the speaker 17. In the present embodiment, OFF (reception) of the talk button within 2 seconds during transmission is included in the transmission time.

On the other hand, in the state where the talk button is pressed, if 2 seconds have passed after returning to the reception mode with the above time limit, the talk button can be released once and then pressed again to transmit. That is, communication can be started. Further, when the talk button is pressed, if the talk button is pressed again within 2 seconds after returning to the reception mode with the time limit, communication cannot be performed. In this case, to that effect is displayed via the display means 27, and the second indication is displayed on the speaker 17.
The BEEP sound of is output to notify the operator.

Communication consists of repetition of transmission and reception,
The communication is started when the first transmission is started, and the communication is ended when 3 minutes have elapsed from the start of communication or when the transmission is stopped for 2 seconds or more and there is a dead state. It is necessary to wait for 2 seconds before transmitting again.

Next, the operation of the call communication mode, which is a unique function of the transceiver according to this embodiment, will be described with reference to the flowchart of FIG.

First, when the call communication mode is set by the mode selection button, a plurality of registered channels are scanned at a certain cycle to search for the calling signal Sc and the tone signal St. During this period, the transmission signal is in a standby state. That is, first, in step 1, channel 1 is set as the channel to be searched. Next, the signal of the channel set in step 2 is received. At this time, squelch chucking is performed at the same time, and the latest usage status of each channel (whether it is in use or not) is registered in the RAM.

Then, in the next step 3, it is determined whether or not the received signal includes the calling signal Sc. That is,
The microcomputer 1 has the squelch signal P turned off and 1 kHz.
The above determination is made depending on whether or not the calling signal Sc is supplied from the amplifier 14. If the calling signal Sc is not detected, the process proceeds to step 4 to update the channel. That is, the set channel is incremented by 1 to make it the set channel. If the set channel before updating is the maximum value (in this case, channel 9), it is cyclically updated to channel 1. After updating the channel in step 4,
Return to step 2. In step 2, step 3 and step 4, a detection loop for the calling signal Sc is formed.

When the calling signal Sc is detected, the process proceeds to step 5 to check the tone signal St. In the received signal, the tone signal St is extracted by the tone detector 15, and the tone detector 15 further compares the tone signal St with the tone type data Dt from the microcomputer 1. That is, it is determined whether or not the transmission destination of the signal radio wave of the channel on which the call signal Sc is transmitted is the self.

When the received tone signal St and the tone type data Dt do not match, the above step 4
Return to step 2 via. If they match, the process proceeds to step 6 to output the fourth BEEP sound indicating that the transmission side has called. In this case, the fourth BEEP sound is output for 10 seconds after the reception radio wave disappears, that is, after the squelch signal P from the carrier detection circuit 22 is turned on.

When the tone button is pressed within 10 seconds after the fourth BEEP sound starts to sound (step 7), the fourth BEEP sound stops, and the tone signal St set from the receiving side to the transmitting side is set. Is transmitted to the current channel (step 8). At this stage, as in the tone squelch communication mode, communication is possible on the current channel.

Although not shown in the flow chart of FIG. 2, even if the talk button is not pressed, the same tone signal S as that of the user is generated within 10 seconds after the fourth BEEP sound starts to sound.
When the signal containing t is received, the fourth BEEP sound is stopped, and the communication becomes possible as in the tone squelch communication mode. Also, the first BEEP sound begins to sound 1
If the talk button is not pressed for 0 seconds and the signal with the same tone as yourself is not received, the fourth BEEP
The sound will stop, the unit will be in standby again, and the channel will be scanned. Further, when the communication similar to the tone squelch communication mode is started after the call, the communication is started 10 seconds after the communication is completed and the channel is scanned. For 10 seconds after the end of communication, the reception state is maintained on that channel. Therefore, if communication is restarted during that time, communication can be performed on that channel as in the tone squelch communication mode.

Next, the calling operation will be described with reference to the flowchart of FIG. Even at the time of calling, before the talk button is pressed, the standby state shown in FIG. 2 is maintained, the squelch chuck is performed while scanning the channel, and the latest usage status of each channel is registered in the RAM.

Then, when the talk button is pressed during the standby (step 101), the microcomputer 1
Control moves to the calling operation, and the next step 102
To find an empty channel. In this process, the channel is changed based on the information (usage status) obtained by the channel scan in the standby mode, and whether or not the channel is in use is chucked based on the squelch signal P (step 103). If the channel is in use, change to another channel based on the information obtained from the channel scan,
Chuck again. If no empty channel is found, the fact is displayed on the display means 27 and the first BEEP sound is output to the speaker 17 (step 10).
7) Return to the standby operation and do not perform the calling operation.

Each channel is randomly selected from the information (usage status) obtained by the channel scan. For example, channel 1 to channel 9
If all of the above are empty channels, the same channel (for example, channel 1) is not always selected.

If an empty channel is found, step 10
In step 4, after transmitting the regulation ID signal, a signal including the calling signal Sc and the tone signal St is transmitted for 3 seconds.
In the next step 105, the fifth BEEP sound is output for 13 seconds after the start of transmission. Then, in the next step 106, it is checked whether or not there is a reply from the other party. That is, when the BEEP sound starts to sound and the signal containing the same tone is received within 13 seconds (that is, when there is a reply from the other party), the fifth BEEP
The sound stops and you can communicate as in the tone squelch communication mode. On the other hand, when 13 seconds have passed without receiving the above signal (that is, when there is no reply from the other party),
When the fifth BEEP sound stops, the standby mode is entered and the channel is scanned.

It should be noted that, for 10 seconds after the end of communication, the reception state on that channel is maintained, and if communication is restarted during that time, communication can be performed on that channel as in the tone squelch communication mode. 10 seconds after the end of communication, the standby state is resumed.

Next, additional functions of this transceiver will be described. This transmitter / receiver has a battery remaining amount display function, and when the lamp / battery chuck / lock key is pressed, the remaining battery amount of the battery 23 is detected once and the display is performed for 15 seconds. This battery display is performed by selectively displaying four symbol displays on the display means 27. Also, the remaining battery level can be set by pressing the above key
Detects the voltage level data Dv from the voltage detection circuit 24 by comparing it with the level data value registered in the RAM in the microcomputer 1 and calculating.

That is, in this battery display, the remaining battery level is classified and displayed, for example, by dividing it into an operable voltage level, an inoperable level and a microcomputer reset level, and further dividing the operable level into three stages. I am trying to display it. For example, according to the voltage drop,
In the case of the first stage level, the second stage level, and the third stage level, when the first stage level is detected, three of the four symbol displays are lit. Next, when the second level is detected, two of the four symbol displays are lit. Next, when the third stage level is detected, only one of the four symbol displays lights up and the third BEEP sound is output.

Next, when the inoperable level is detected, one symbol display is blinked and the power is turned off.
At this time, the key is not accepted. Once this level is displayed, even if the voltage level of the battery 23 is restored and the inoperable level is no longer detected, the above display still flashes and the power is still off. The power will not turn on until the power key is pressed. When the power key is pressed, the power is turned on to turn off the display and the third BEEP sound.

Next, when the microcomputer reset level is detected, a reset signal is input to the microcomputer 1 to reset the microcomputer 1. At this time, all the display by the display means 27 disappears.

When the lamp / battery check / lock key is pressed while the power is on, the lamp lights up and the battery is displayed. Press the key again to turn off both. Even if you do not press the key again, it will automatically turn off in 15 seconds after the battery is displayed. While the lamp is lit, talk button and lamp / battery check /
When any key other than the lock key is pressed, the lamp automatically turns off 15 seconds after the key is last pressed.

When the lamp / battery check / lock key is pressed for 2 seconds or more, the lock display is displayed on the display means 27. In this case, input of keys other than the talk button, lamp / battery check / lock key, and monitor key is invalid. When the lamp / battery check / lock key is pressed again for 2 seconds or longer, the lock display turns off and the input of each key is accepted.

When the lamp / battery check / lock key is pressed for 2 seconds or longer when the power is off,
A lock display is displayed on the display means 27. In this state (off-lock state), pressing the power key does not turn the power on. In this off-lock state, if the lamp / battery check / lock key is pressed for 2 seconds or more, the lock display disappears and the off-lock state is released.

The periods, output times, etc. of the first to fifth BEEP sounds are as shown in Table 1 below.

[0061]

[Table 1]

As described above, according to the transceiver of this embodiment, the calling signal S having a frequency of 1 kHz is called at the time of calling.
c and the tone signal St are superimposed and transmitted, and at the time of standby, it is first detected whether or not there is a call signal in each channel, and the tone signal St is checked only when the call signal Sc is detected. Since the calling signal Sc itself is a relatively high frequency signal of 1 kHz, which channel is being called can be searched for in a very short time. In this embodiment, 20 ms per channel
This is a very short time as compared with the conventional case of 200 ms per channel. Therefore, it is possible to shorten the time from when the transmitting side makes a call to when the receiving side receives a response, and it is possible to improve operational convenience.

In the above embodiment, the calling signal Sc and the tone signal St are superimposed and transmitted at the time of calling, but as another example, for example, as shown by a broken line block in FIG. A 1 kHz modulator 30 is connected from a predetermined terminal to the transmission line L. In the figure, when this modulator is connected, the signal path is as shown by the broken line. Then, the microcomputer 1 outputs the identification signal Sa to the modulator 30. The identification signal Sa has the same function as that of the tone signal St, and is a signal obtained by converting the identification number of the transmitting side or the identification number of the other party into a signal. In this case, the identification number can be set / changed by key input to the input means 26, as in the case of the tone signal St.

The 1 kHz modulator 30 has a 1 kHz oscillator inside, and modulates a 1 kHz sine wave from this oscillator based on the identification signal Sa from the microcomputer 1 and outputs it as a 1 kHz modulation signal Sb. To do. 1k
The Hz modulation signal Sb is supplied to the transmission line L and is combined with the tone signal St from the tone oscillator 4.

On the other hand, the other party is the IF amplification / detection circuit 13
Of the demodulated signal Ss from the 1 kHz amplifier 14,
The 1 kHz modulated signal Sb is detected. When the 1 kHz modulated signal Sb is detected, it is determined that “the calling signal is detected”, and then the tone signal St is collated. When it is determined that they are the same in the matching process of the tone signal St, the identification signal Sa is extracted from the detected 1 kHz modulated signal Sb.

Then, in the microcomputer 1, the identification signal Sa is collated with the identification number data registered in the RAM. For example, if the identification number data is the identification number on the transmission side, the display means 27 is displayed from the microcomputer 1. , The sender's name and / or identification number is displayed. In this case, it is possible to confirm who the sender is on the display, and it is possible to further improve the convenience of operation.

When the identification number data is the receiving side identification number, the process of enabling communication can be performed only when the identification number data is the same as the set identification number. That is, communication is possible only when it is determined that the tone signals St are the same and when the identification numbers are the same. Therefore, in this case, the identification accuracy can be further improved.

[0068]

As described above, according to the transceiver of the present invention, a superimposed signal obtained by superimposing a calling signal having a frequency higher than that of the tone signal on the tone signal is set corresponding to a plurality of frequency bands. Call transmitting means for transmitting to an empty channel that is communicable among the specified frequency channels, first detecting means for detecting the calling signal from the superimposed signal transmitted to the empty channel, and the empty channel. Second detecting means for detecting the tone signal from the transmitted superimposed signal, the first detecting means detecting the calling signal, and the second detecting means detecting a predetermined tone signal. When it is detected, communication is enabled, so it is possible to shorten the time from when the sending side makes a call to when the receiving side receives a response. It can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of a transceiver according to the present invention (hereinafter referred to as a transceiver according to the embodiment).

FIG. 2 is a flowchart showing the operation of the transceiver according to the present embodiment in a standby state.

FIG. 3 is a flowchart showing a calling operation of the transceiver according to the present embodiment.

[Explanation of symbols]

 1 Microcomputer 2 Microphone 3,16 Low frequency amplifier 4 Tone oscillator 5 Local oscillator 6,11 High frequency amplifier 12 Mixer 13 IF amplification / detection circuit 14 1kHz amplifier 15 Tone detector 17 Speaker 21 PLL 22 Carrier detection circuit 23 Battery 24 Voltage detection Circuit 25 A / D converter 26 Input means 27 Display means

Claims (3)

[Claims] 1. A transmitted tone signal is detected, and the detected tone signal is one of a plurality of types of tone signals.
When the tone signal has been set in advance, in the transceiver that enables communication, the superimposed signal obtained by superimposing a ringing signal having a frequency higher than that of the tone signal on the tone signal corresponds to a plurality of frequency bands. A call transmitting means for transmitting to an empty channel in which communication is possible among the set frequency channels; a first detecting means for detecting the calling signal from the superposed signal transmitted to the empty channel; Second detection means for detecting the tone signal from the superimposed signal transmitted to the channel, the first detection means detecting the calling signal, and the second detection means for a predetermined tone. A transceiver, which is capable of communicating when a signal is detected. 2. The calling signal has a frequency of 50.
Transceiver according to claim 1, characterized in that it is higher than 250 Hz. 3. The transmitter / receiver according to claim 1, wherein the call transmitting means is connected to a combining means for superimposing the call signal and the identification signal.