JPH11154881A - Tone squelch control radio device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable communication with a simple operation that does not have interferences operation by measuring electric field intensity of a frequency in which speech communication is performed and controlling radio equipment, according to a constant operation flow, in synchronization with the opposity facing radio equipment. SOLUTION: When certain electric field intensity is confirmed in a frequency of an initial channel is master radio equipment A, it is decided that the same frequency is used by another group, a group tone is sent to radio equipment B by pressing a press button 13 for a fixed time and it is communicated to the equipment B such that the equipment A performs channel scan and searches another free channel. After half, channel scan is performed for a fixed time, and a free channel in which there is not electric field intensity is retrieved. When a free channel is found, channel setting of the equipment A is performed on the channel. After a group tone has been sent to the equipment B in the channel frequency by pressing the button 13 for a fixed time, the equipment A goes into a waiting state for a fixed time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press-talk radio apparatus having a selective call function for transmitting and receiving a single wave, and capable of performing communication without interference with a simple operation.

[0002]

2. Description of the Related Art Conventionally, press-talk type radios have been used in various fields such as business radio, amateur radio, and low-power radio. Because it can be used, it is generally widely used. FIG. 3 shows a configuration example of a conventional press-talk type wireless device. In FIG. 1, the wireless device includes an antenna 1, a transmission / reception switch 2 for switching the connection of the antenna 1 between a transmission side and a reception side, and a reception high frequency signal as an intermediate frequency signal (I
(A F signal), a demodulation section 5 for demodulating an IF signal, a control section 6 for controlling the demodulated signal or audio signal and the entire radio, and an output signal from the control section 6 to audio. Speaker 7, a microphone 8 for converting an operator's voice into an electric signal, an operation display unit 9 for setting a used frequency, etc., and a predetermined frequency modulated by an audio signal from the microphone 8 signal-processed by the control unit 6. The modulation unit 11 includes a modulation unit 11 that outputs a modulated wave signal, a transmission unit 12 that amplifies the modulated wave to a specified transmission level, and outputs the amplified signal.

When performing communication in the above configuration, first,
Select one frequency wave of an arbitrary channel from the frequency range assigned by the Radio Law together with the communication partner,
The frequency of the wireless device is set to the frequency by the operation display unit 9. At the time of transmission, by pressing the press button 13, the transmission / reception switch 2 is switched to the transmission unit side and transmission becomes possible, and the transmission is performed while the press is continued. When transmission is completed and the press of the press button 13 is released,
The transmission is interrupted, and the transmission / reception switch 2 is switched to the receiving unit side to be able to receive.

However, as described above, the frequency range that can be used is limited by the Radio Law. Therefore, when a plurality of groups use the same frequency in the same area at the same time, the wireless device may not be able to communicate during a call. A problem arises in that radio waves of a group other than the other party are received and overlapped with voice during a call to cause interference. Furthermore, when receiving an interference signal with the same frequency and a larger electric field strength than the other radio device during a call,
In some cases, a transmission radio wave from a communication partner cannot be received and communication becomes impossible. In this case, the other party cannot confirm that you are experiencing interference,
There is a problem that communication becomes unilateral.

As a method for preventing such interference or interference, for example, there is a method using tone squelch. This is because, within a group, a specific tone signal outside the voice band is set, and when transmitting, a modulated wave by the voice signal to which the tone signal is added is transmitted, while the receiving side transmits the modulated signal. From among them, a squelch circuit is opened for a signal whose tone signal has been identified by a tone selection circuit, and an audio output circuit operates to output audio from a speaker.

[0006] The operation of the radio device under the tone squelch control will be described with reference to the flowchart shown in FIG. In the figure, first, both opposing wireless devices are powered on.
After N (F1), the frequency and group tone to be used are set by operating the operation display section 9 (F2). by this,
Both radios are ready for reception (F
3). Receives any signal in the standby state (F4
Yes, if a group tone signal is identified (F5
Yes), the squelch circuit 61 is opened, the sound output circuit is operated, and the transmission circuit of the wireless device of the own station is cut off (F6), and the reception state of the transmission signal from the partner station is entered (F7). When the transmission of the partner station ends, the reception of the group tone signal ends (F8), and the reception ends (F9).

If there is no need for a response, the process returns to waiting for F3. When sending a response (with F10),
The press button 13 is pressed (F11), and the group tone signal is added (F12). The transmission of the sound is enabled (F13). When the transmission is finished, the press of the press button 13 is released (F14) to end the call ( F15), the process returns to the standby state in which reception of F3 is possible.

[0008] When there is no received signal in F3 standby after the above-mentioned initial setting (no F4) and a call is transmitted to the partner station, the user presses the press button 13 (F11), and thereafter performs a transmission operation. If there is a received signal at F5 in the standby after initialization and no group tone is identified, (F
5), and return to the standby state of F3. When terminating the communication, the power supply of the wireless device is turned off when the apparatus is in a standby state for receiving data (F16).

As described above, according to the tone squelch control method, even if a signal of another group having the same frequency is received, no sound is output from the speaker unless the group tone signal is identified, so that no interference occurs.

[0010]

However, in the radio equipment of the tone squelch control system, when a squelch circuit is opened by receiving a transmission signal from a partner station, communication of another group of the same frequency is also received. However, there is a problem that the sound is output from the speaker as a sound and interference occurs. Also, if the harmonic components of the tone signal frequency of the other group and their levels are within the tone signal identification range of the own station radio, the tone signal of the other group opens the squelch circuit of the own station. In some cases, the communication content of another station is output as audio from a speaker, causing interference. If the wireless device in the own group or the own station is set to turn off the operation of the transmitting circuit when the squelch circuit is opened, while the transmission of the other group continues, A problem arises in that the transmission signal cannot be emitted from the wireless device of the own station.

As another method for avoiding interference, there is a method of automatically selecting an empty channel when interference occurs. However, since coordination with a partner station cannot be taken, either one of them is selected. After selecting a station, it is common to wirelessly communicate the empty channel to the other party, re-set the frequency after each other, and then resume communication. In this case, there is a problem that the operation frequently occurs because the user frequently intrudes into the transmission / reception area.
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and provides a radio device capable of performing communication without interference by a user without much awareness of a radio wave environment and with a simple operation. The purpose is to:

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a press-talk radio apparatus having a selective calling function of one transmission / reception wave, which is provided with an electric field strength measurement function at a frequency during a call. It has a memory and a timer function for controlling the radio in accordance with a constant operation flow while synchronizing with time between the radios.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a schematic diagram showing an embodiment of a radio apparatus of the press-talk system by tone squelch control according to the present invention. In FIG. 1, the wireless device includes an antenna 1, a transmission / reception switch 2, a reception unit 3, a signal distributor 4, a demodulation unit 5, a control unit 6, a speaker 7, a microphone 8, an operation display unit 9, a detection unit 10, a modulation unit It comprises a unit 11, a transmission unit 12, and a press button 13. In the above configuration, the functions and transmission / reception operations of the circuit configuration excluding the signal distributor 4, the control unit 6, and the detection unit 10 are as follows.
Since the operation is the same as that of the wireless device in the related art, the description is omitted. A feature of the present invention is that the signal distributor 4 is arranged between the receiving unit 3 and the demodulation unit 5 and the signal distributor 4
One of the outputs outputs a receiver output signal to the demodulator 5 as in the conventional case. The other outputs a receiver output signal to the detector 10. The detector 10 detects the input signal and detects the electric field level of the received signal of the wireless device.
The electric field level is displayed on the operation display unit 9 via the control unit 6. Further, the control unit 6 includes a squelch control circuit 61, a ROM and a RAM for controlling a communication operation as described below, and a C including a timer for performing time control.
PU62 is provided.

When performing communication with the above-described configuration, first, one frequency of an arbitrary channel is selected from the frequency range allocated by the Radio Law together with the communication partner, and the operation display unit 9 sets the radio to the frequency. Frequency setting.
At the time of transmission, by pressing the press button 13, the transmission / reception switch 2 switches to the transmission unit side to enable transmission, and transmits a tone signal by adding it to a carrier wave. After that, they talk while continuing to press. Also,
When the press of the press button 13 is released after the transmission is completed, the transmission is cut off, and the transmission / reception switch 2 is switched to the receiving unit side to be able to receive.

Next, the communication operation of the above-mentioned wireless device according to the present invention will be described as one-way communication between the wireless device A and the wireless device B with reference to the flowchart shown in FIG. First, after the power is turned on (S1, S18) on both sides, the operation display unit 9
To set the initial channel and group tone, and to set the parent wireless device at the start (S2, S1)
9). Here, the wireless device A is a master wireless device. When the setting is completed, the electric field strength of the initial channel is measured on both sides (S
3, S20). In the case where the electric field strength of any signal is confirmed at the frequency of the initial channel in master radio A (S4)
Yes), it is determined that the same frequency is being used by another group,
The press button 13 is pressed to the wireless device B for a predetermined time (for example, 2 seconds) to transmit a group tone (S5), and the wireless device A notifies the wireless device B that the channel is scanned to search for another available channel. . After sending the group tone,
Perform a channel scan for a certain period of time (for example, 5 seconds)
An empty channel having no electric field strength is searched (S6).

The setting of the scan range, the channel interval, the specific channel setting, and the like when performing the channel scan can be freely set at the time of the initial settings S2 and S19. In the above channel scan, if no free channel is found within a predetermined time (no S7), the process returns to the initial setting S2. If an empty channel is found (S7 is present), the channel of the radio A is set for that channel (S8), and the press button 13 is pressed for the radio B at the frequency of the channel for a certain period of time (for example, 2 seconds). After pressing and transmitting the group tone (S9), the apparatus enters a waiting state for a predetermined time (for example, 5 seconds) and waits for a response signal from the wireless device B using the same group tone (S1).
0). When the response signal of the group tone is received from the wireless device B within a predetermined time (Yes in S11), the wireless devices A and B enter a communicable state (S12). When the response signal of the group tone from the wireless device B is not received (S11)
No), the radio A returns to S5 and starts searching for an empty channel again.

If the electric field strength is not confirmed in the measurement in S3 after the initial setting (No in S4), the initial channel is determined to be an empty channel, and the apparatus shifts to a standby state (S15). If there is no reception of the group tone signal for two seconds from the wireless device B during the standby (No in S16), the wireless devices A and B enter a communicable state on the channel (S12). Also,
If the group tone is received from the wireless device B during the waiting in S15 (S16 is present), the process proceeds to S5, and the group tone is transmitted as described above.

If there is no interference in the communication state of S12 (S12
13), the call is completed and ended (S14). When interference occurs in the communication state (S13 is present), the press button 23 is pressed for a predetermined time (for example, one second) (S1).
7) Transmit a group tone (S34), return to S5, and start searching for an empty channel.

On the other hand, the radio B checks the electric field intensity at the set frequency as a result of the electric field intensity measurement in S20 (S2).
1), it is determined that the same frequency is being used by others, and the apparatus enters a standby state (S22), and waits for a signal (group tone signal of S5) from the master radio A. When a group tone is received from the wireless device A in the standby state (S23 is present)
Is in a standby state for 5 seconds when the radio A performs the channel scan (S24). If there is no group tone reception from the wireless device A in the standby state of S22 (S22)
23) presses the press button 13 for two seconds in order to inform that the radio B
Is transmitted (S34), and the process returns to the standby state of S22. After waiting in S24, a channel scan is performed to capture a group tone signal of the frequency generated by the wireless device A (S25).

When the group tone is received from the wireless device A in the above channel scan (S26 is present), the channel of the wireless device B is set to the frequency (S27), and the fact that the channel is shifted is notified to the wireless device A. For this purpose, the user presses the press button 13 for 2 seconds on the channel to transmit a group tone (S28). With this, the wireless devices A and B
Becomes communicable (S29). When the group tone from the wireless device A is not received in the channel scan in S25 (No in S26), the group tone is transmitted to the wireless device A for 2 seconds (S34), the process returns to the standby state in S22, and the above-described operation is performed. Move on.

If the electric field strength is not confirmed in the electric field strength measurement after the initial setting (No in S21), it is determined that the channel is an empty channel, and the apparatus shifts to a standby state (S32), and the group tone transmission signal from the master radio A in S5. Wait for. In the meantime, when no group tone signal is received from the wireless device A (S
33), the communication is enabled (S29). Also,
If a group tone signal has been received (with S33), S
Then, the flow shifts to 24, and thereafter, to the above-described operation.

If there is no interference in the communication state of S29 (S3
0), the call is completed and ended (S31). Further, when radio interference occurs in the radio B in the communication state (S30)
Yes, the press button 13 is pressed for one second (S35), a group tone is transmitted (S34), and a transition is made to the standby state of S22. Thereafter, the operation proceeds to the above-described operation.

[0023]

As described above, the radio equipment of the tone squelch control system according to the present invention measures the electric field strength of the reception signal of the radio equipment by the detection unit, and performs the interference by the CPU control including the squelch control circuit and the timer. Is configured to detect the occurrence of interference and to avoid the occurrence of interference according to a certain flow. As a result, the present invention has a remarkable effect that a communication channel can be changed while cooperating between groups by a simple operation of a wireless device, and interference during a call can be easily avoided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a press-talk type wireless device according to the present invention.

FIG. 2 is a flowchart illustrating the operation of the wireless device of FIG. 1;

FIG. 3 is a schematic configuration diagram showing an example of a conventional press-talk wireless device.

FIG. 4 is a flowchart illustrating the operation of the wireless device of FIG. 3;

[Explanation of symbols]

1. Antenna, 2. Transmit / receive switch,
3. a receiving section, 4 ... a signal distributor according to the present invention,
5 demodulation unit, 6 control unit, 7 speaker
8 ・ ・ Microphone 、 9 ・ ・ Operation display unit 、 1
0 ··· Detector according to the present invention 11 ··· Modulator 1
2. transmission section, 13 press button, 61 squelch control circuit according to the present invention, 62 CPU according to the present invention

Claims (1)

[Claims] In a radio apparatus of a press-talk system, an electric field intensity measuring function for measuring an electric field intensity at a frequency during a call and a time-synchronized radio apparatus based on the electric field intensity while synchronizing with each other. A tone squelch control radio device having a memory and a timer function for controlling the radio device according to a certain operation flow so as to avoid occurrence of interference.