JPH08186508A - Radio communication system - Google Patents

Abstract

PURPOSE: To prevent a noise from being outputted by interrupting a carrier signal after the laspe of prescribed time longer than a tone recognizing term on the reception side from the interruption of a tone signal in the case of tone/ voice mixing radio communication. CONSTITUTION: On the transmission side, the tone signal of the destination is generated and mixed with a voice signal, and the carrier signal is modulated and transmitted. On the reception side, the tone signal and the voice signal are separated from the demodulated mixed signal and when it is matched with the tone signal of a present station, an amplifier 114 outputs a voice signal but when it is not matched, that signal is muted. Since the tone recognizing term is provided to surely detect the tone, even when the tone signal is not matched, the voice signal is continuously outputted during the recognizing term. Therefore, the tone signal and the carrier signal are not simultaneously interrupted at the time of transmission end but the carrier signal (silence) is transmitted for prescribed time even after the interruption of the tone signal and interrupted later. Thus, the carrier signal is interrupted after the detection of tone signal interruption and the mute of the voice output on the reception side so that no noise can be outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system for transmitting and receiving by a plurality of radios, and in particular, modulating a carrier signal (carrier wave) with a voice signal and a tone signal and transmitting and receiving as a radio wave to a receiving side. The wireless device (relay station) relates to a wireless communication system that switches whether to output (relay) voice by a tone signal.

[0002]

2. Description of the Related Art FIG. 5 is a diagram for schematically explaining a wireless communication system 1 which performs wireless communication between wireless devices without passing through a relay station. The configuration of this figure will be described below. It should be noted that, throughout the drawings, the same components are denoted by the same reference numerals. In the figure, a wireless communication system 1 includes wireless devices 2 and 3 that perform wireless communication without going through a relay station. Radios 2 and 3
The antenna 4 includes a transmitting circuit 5 and a receiving circuit 6 connected to the antenna 4, and a signal processing unit 7 connected to the transmitting circuit 5 and the receiving circuit 6. The signal processing unit 7 is connected to a transmitter / receiver (not shown) (microphone, speaker, etc.). Further, the signal processing unit 7 outputs to the transmission circuit 5 a modulated signal obtained by modulating a carrier signal with a mixed signal of a tone signal and an audio signal input from a microphone or the like during a transmission operation. Further, during reception operation, a tone signal is detected from the received radio wave received, and when it matches the tone frequency of the local station, the speaker outputs sound. The tone signal is a signal (frequency) assigned to the destination and the own station, and when the tone frequency assigned to the own station and the tone signal of the received radio wave do not match,
Or, when the tone signal is not received, the audio output is cut off (muted) to prevent interference. The carrier signal is
A carrier wave, which is the frequency of a channel. Further, switching between transmission / reception is performed by a press switch or the like not shown.

Next, the operation of the wireless communication system 1 for performing wireless communication between wireless devices without using a conventional relay station will be described with reference to FIG. FIG. 6 is a time chart showing the operation of the conventional wireless communication system 1. In FIG. 5, the wireless device 2
The case of transmitting data from the wireless device to the wireless device 3 will be described. The wireless device 2 transmits a modulated signal obtained by modulating a carrier signal with a mixed signal obtained by mixing a voice signal and a tone signal as a radio wave.

At time t31, the press switch or the like of the radio device 2 is turned off to end the mixing of the tone signal and the voice signal and the end of the modulation of the carrier signal. As a result, the wireless device 2 enters the receiving state, and the tone signal and the carrier signal are not given to the transmitting circuit 5. That is, when the press switch or the like is turned off, transmission of both the tone signal and the carrier signal ends. Almost at the same time, the wireless device 3 detects the disconnection of the tone signal from the wireless device 2. Then, at time t32, the wireless device 3 recognizes the disconnection of the tone signal from the wireless device 2 and shuts off (mutes) the audio output.
The time difference T31 (t31 to t32) is generated in order to reliably detect the disconnection of the tone signal from the wireless device.

Next, a radio communication system 11 which performs radio communication via a relay station will be described. The reason why the wireless communication is performed via the relay station is to expand the communication area. FIG. 7 is a diagram schematically illustrating a wireless communication system 11 that performs wireless communication via a relay station. The wireless communication system 11 includes a relay station 8 and wireless devices 2 and 3 that perform wireless communication via the relay station 8. Since the configurations of the wireless devices 2 and 3 have been described above, the description thereof will be omitted. When the tone signal can be detected from the radio wave transmitted from the radio device, the relay station 8 extracts the voice signal from the radio wave and newly mixes the tone signal with the voice signal. Then, when the carrier signal can be detected, the new carrier signal is modulated with the mixed signal and transmitted to another radio device. That is, when both the tone signal and the carrier signal can be detected, the new tone signal and the carrier signal are transmitted, and when only the carrier signal can be detected, only the new carrier signal is transmitted. still,
The new tone signal and carrier signal may have the same frequency as the received tone signal and carrier signal.

Next, the operation of the wireless communication system 11 which performs wireless communication via the conventional relay station will be described with reference to FIG.
FIG. 8 is a time chart showing the operation of the conventional wireless communication system 11. In FIG. 7, a case of transmitting from the wireless device 2 to the wireless device 3 via the relay station 8 will be described. The wireless device 2 transmits a modulated signal obtained by modulating a carrier signal with a mixed signal obtained by mixing a voice signal and a tone signal as a radio wave. Further, the relay station 8 takes out a voice signal from the radio wave from the radio device 2, mixes a new tone signal with the voice signal, modulates a new carrier signal with the mixed signal, and transmits the modulated signal to the radio device 3. There is.

At time t41, the press switch or the like of the radio device 2 is turned off to end the mixing of the tone signal and the voice signal, and the end of the modulation of the carrier signal. As a result, the wireless device 2 enters the receiving state, and the tone signal and the carrier signal are not given to the transmitting circuit 5. That is, when the press switch or the like is turned off, transmission of both the tone signal and the carrier signal ends. Almost at the same time, the relay station 8 detects the disconnection of the tone signal (carrier signal) from the wireless device 2. Then, at time t42, the relay station 8 recognizes the disconnection of the tone signal (carrier signal) from the wireless device 2 and ends the transmission of the tone signal (carrier signal) to the wireless device 3. Thus, the time difference T41 (t41 to t42)
The reason is that the transmission disconnection of the tone signal from the wireless device is surely detected. Almost at the same time, the wireless device 3 detects the disconnection of the tone signal from the relay station 8. Then, at time t43, the wireless device 3 recognizes the disconnection of the tone signal from the relay station 8 and cuts off (mutes) the voice output.
The time difference T42 (t42 to t43) is generated in order to reliably detect the disconnection of the tone signal from the relay station (radio device).

[0008]

However, in the wireless communication system 1 as described above, as shown in FIG.
Since the recognition period (T31) for surely detecting the transmission interruption of the tone signal is provided, there is a time difference (T31) after the wireless device 2 finishes the transmission (transmission interruption of the tone signal and the carrier signal). Since the wireless device 3 cuts off (mutes) the audio output, the audio output of the wireless device 3 is still being performed during the time difference (T31). Therefore, during the time difference (T31), the wireless device 3 receives noise from the outside and outputs this noise as a voice to the user.

The radio communication system 11 as described above
Then, as shown in FIG. 8, since the relay station 8 is provided with the recognition period (T41) for surely detecting the disconnection of the tone signal, the wireless device 2 finishes the transmission (tone signal,
Since the relay station 8 finishes relaying the tone signal and the carrier signal with a time difference (T41) after the carrier signal transmission is interrupted, the relay station 8 continues to be relayed during the time difference (T41). . Therefore, during the time difference (T41), the relay station 8 receives noise from the outside, adds the tone signal and the carrier signal as a voice signal, and transmits (relays) the noise to the wireless device 3. Since the wireless device 3 is also provided with the recognition period (T42) for surely detecting the transmission interruption of the tone signal, after the relay station 8 finishes the transmission (transmission interruption of the tone signal and the carrier signal). Since the wireless device 3 cuts off (mutes) the audio output at the time difference (T42), the audio output of the wireless device 3 is still being performed during the time difference (T42). Therefore, during the time difference (T42), the wireless device 3 receives noise from the outside and outputs this noise as a voice to the user. That is,
During the time difference (T41), the relay station 8 transmits noise from the outside to the wireless device 3, and during the time difference (T42),
The wireless device 3 receives noise from the outside and outputs the noise to the user during the time difference (T43).

In order to prevent this, it is conceivable to shorten the recognition period (T31, T41, T42) on the receiving side as much as possible, but this makes it impossible to reliably detect a tone signal transmission interruption. Challenges arise.

[0011]

In order to solve the above-mentioned problems, the present invention has a plurality of radios for transmitting and receiving by modulating a carrier signal with a voice signal and a tone signal, and the radios receive the radio signals. In this case, the wireless communication has a tone signal detecting means for detecting the tone signal, and the tone signal detecting means has a tone signal recognition period from the detection of the transmission interruption of the tone signal to the interruption of the output of the voice signal. In the system, at the end of transmission, the wireless device includes transmitting means for cutting off the tone signal and then cutting off the carrier signal after a predetermined time has elapsed, the predetermined time being equal to or longer than the tone signal recognition period. Is characterized in that.

Further, the carrier signal is modulated by a voice signal and a tone signal, and a plurality of radios for transmitting and receiving through the relay station are provided, and the relay station detects the tone signal at the time of relaying. In the wireless communication system, the tone signal detecting means has a tone signal recognition period from when the tone signal detecting means detects the transmission interruption of the tone signal to when the relaying of the voice signal is finished, A transmission means for disconnecting the carrier signal after a lapse of a predetermined time from the transmission of the tone signal, and the predetermined time is
It is characterized in that it is longer than the tone signal recognition period.

Further, the carrier signal is modulated by a voice signal and a tone signal, and has a plurality of radios for transmitting and receiving via a relay station, and the relay station has a tone signal from the radio for transmitting at the time of relaying. The first tone signal detecting means for detecting the interruption of the transmission of the tone signal from the radio device which performs the transmission until the end of the relay of the voice signal. Has a first tone signal recognition period,
When receiving, the radio device for receiving has a second tone signal detecting means for detecting a tone signal from the relay station, and the second tone signal detecting means cuts off the transmission of the tone signal from the relay station. The second from the detection until the output of the audio signal is cut off
In the wireless communication system having the tone signal recognition period described above, the wireless device that performs the transmission includes a transmission unit that disconnects the tone signal at the end of transmission and then disconnects the carrier signal after a predetermined time has elapsed. , The predetermined time is
It is characterized in that it is equal to or more than the sum of the first tone signal recognition period of the relay station and the second tone signal recognition period of the radio device.

[0014]

According to the first aspect of the invention, when the transmission side radio device finishes the transmission, it first cuts off the transmission of the tone signal. Then, after transmitting only the carrier signal for a predetermined time that is set longer than the tone signal recognition period of the receiving-side wireless device, the carrier signal is cut off. Then, the radio device on the reception side receives only the carrier signal (silence) from the radio device on the transmission side during the tone signal recognition period, and cuts off (mutes) the voice output after the tone signal recognition period has elapsed.

According to the second aspect of the invention, when the radio device on the transmitting side finishes the transmission, it first disconnects the tone signal. Then, after transmitting only the carrier signal for a predetermined time set longer than the tone signal recognition period of the relay station, the carrier signal is cut off. Then, the relay station receives only the carrier signal (silence) from the transmitting side radio during the tone signal recognition period, but since it is during the tone signal recognition period, the receiving side radio receives the tone signal and the carrier signal. The signal is transmitted (relay), and after the tone signal recognition period has elapsed, the transmission (relay) of the voice signal is finished.

According to the third aspect of the invention, when the wireless device on the transmitting side finishes the transmission, it first disconnects the tone signal. Then, after transmitting only the carrier signal for a predetermined time set longer than the sum of the tone signal recognition period of the relay station and the tone signal recognition period of the wireless device, the carrier signal is cut off. Then, the relay station receives only the carrier signal (silence) from the transmitting side radio during the tone signal recognition period, but since it is during the tone signal recognition period, the receiving side radio receives the tone signal and the carrier signal. The signal is transmitted (relay), and after the tone signal recognition period has elapsed, the transmission (relay) of the voice signal is finished. Then, the receiver radio receives the carrier signal (silence) from the relay station during the tone signal recognition period.
After receiving only the tone signal recognition period, the audio output is cut off (muted).

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of the configuration of wireless devices 2 and 3. In the figure, an input unit 101 is for designating a transmission destination, a channel, etc., and an operation state is output to the microcomputer 102. The microcomputer 102 has an input unit 10
1. When an operation state of a press switch or the like that specifies a transmission operation (not shown) is detected, and the press switch or the like is ON (during transmission), the antenna changeover switch 110 is switched to the transmission side and the press switch or the like is turned from ON to OFF. When operated, the antenna changeover switch 110 is changed over to the receiving side after a lapse of a predetermined time described later. Also, the input unit 101
The tone oscillator 105 reads out the tone and channel designation data corresponding to the operation state of the tone oscillator 105 from the memory 103.
The tone designating data is output to and the channel designating data is output to the carrier oscillator 104. In addition, the microcomputer 102
Reads the tone frequency of its own station stored in the memory and outputs it to the frequency comparator 116. Memory 103
Stores a tone, channel designation data, a tone frequency of its own station, etc., and outputs it to the microcomputer 102 by operating the input unit 101 or the like.

The carrier oscillator 104 is a microcomputer 102.
The designated data of the channel corresponding to the operation of the input unit 101 is input from, and a carrier signal (carrier wave) corresponding to the designated data of the channel is generated and output to the modulator 108. The tone oscillator 105 receives the tone designation data of the transmission destination corresponding to the operation of the input unit 101 from the microcomputer 102, generates a tone signal corresponding to the tone designation data, and outputs the tone signal to the modulator 108. The tone signal output from the tone oscillator 105 is input from the microphone 106, mixed with the audio signal amplified by the amplifier 107, and then input to the modulator 108.
The input signal from the microphone 106 is determined to be valid / invalid by a press switch or the like. The modulator 108 mixes the mixed signal of the voice signal and the tone signal with the carrier oscillator 10.
4 receives the carrier signal and the carrier oscillator 10
The carrier signal from 4 is modulated with the mixed signal and output to the transmission circuit 109. The transmission circuit 109 includes the modulator 108.
When the antenna changeover switch 110 is on the transmitting side, the output is transmitted as a radio wave via the antenna changeover switch 110 and the antenna 111. As described above, the antenna changeover switch 110 remains on the transmitting side until the carrier signal transmission is cut off after the press switch is turned off.

The receiving circuit 112 receives the radio waves when the antenna changeover switch 110 is on the receiving side.
The signal is received through the antenna changeover switch 110, detection is performed, a mixed signal of the tone signal and the voice signal is extracted, and is output to the filter 113 and the tone decoder 115. The filter 113 cuts out the tone signal from the mixed signal from the receiving circuit 112, extracts a voice signal, and outputs the voice signal to the amplifier 114. The amplifier 114 amplifies the audio signal from the filter 113 and outputs it from the speaker 117. The output of the frequency comparator 116 mutes the amplifier 114. The tone decoder 115 includes the receiving circuit 1
The tone signal is extracted from the mixed signal from 12 by extracting the tone signal and output to the frequency comparator 116. The frequency comparator 116 compares the tone signal from the tone decoder 115 with the tone frequency of its own station stored in the memory 103, and if they are the same, controls the amplifier 114,
Audio is output, and if they are not the same, the amplifier 114 is controlled to not output audio (mute). Since the frequency comparator 116 has a recognition period for surely detecting the tone signal transmission interruption, the frequency comparator 116 mutes after a predetermined time has elapsed from the tone signal transmission interruption.

The radios 2 and 3 are normally in a receiving state (on the receiving side of the antenna changeover switch 110). When the tone signal of the radio wave and the tone frequency of the local station match, voice output is performed and the tone of the radio wave is outputted. Even if the signal and the tone frequency of the local station do not match, voice output is performed during the recognition period.
Since the configuration of the relay station 8 has been described above, its explanation is omitted.

Next, the operation of the radios 2 and 3 will be described with reference to FIG. FIG. 2 is a flowchart showing the processing of the microcomputer 102. When the power of the wireless devices 2 and 3 is turned on, the processing is started. In step S1, as the initial setting, the antenna changeover switch 110 is changed over to the receiving side and the memory 1
The tone frequency of the own station stored in 03 is read,
It outputs to the frequency comparator 116, and moves to step S2.
In step S2, it is detected whether or not the press switch or the like is turned on, and if it is turned on, the process proceeds to step S3 and turned off.
If so, step S2 is repeated, and the wireless devices 2 and 3 remain in the receiving state.

In step S3, as transmission processing, tone and channel designation data corresponding to the operation of the input unit 101 is read from the memory 103, the tone designation data is stored in the tone oscillator 105, and the channel designation data is stored in the carrier oscillator 104. Output. Further, the antenna changeover switch 110 is changed over to the transmitting side, and the process proceeds to step S4. In step S4, it is detected whether the press switch or the like remains ON or is operated OFF (whether transmission is in progress).
If it remains N, the transmission is still in progress, so step S4 is repeated until the transmission is completed. If it is operated to OFF, the transmission is completed and the procedure moves to step S5.

In step S5, the tone oscillator 105 is controlled to end the transmission of the tone signal (discontinue transmission of the tone signal), and the process proceeds to step S6. In step S6, the process waits for a predetermined time to be described later, and after the predetermined time has elapsed, step S6
Go to 7. In step S7, the carrier oscillator 104 is controlled to end the transmission of the carrier signal (discontinue the transmission of the carrier signal), and the process proceeds to step S8. In step S8, the antenna selector switch 110 is switched to the receiving side, and the process proceeds to step S2. The process is continued until the wireless devices 2 and 3 are powered off. The wireless devices 2 and 3 are in the normal reception state, and step S2 is repeated. When transmitting (press switch etc. ON), steps S3 to S8 are performed.

Next, the operation of the first embodiment of the present invention will be described with reference to FIG. The present embodiment is a wireless communication system 1 that performs wireless communication between wireless devices without going through a relay station.
As in the case of the conventional technique, the case of transmitting from the wireless device 2 to the wireless device 3 will be described with reference to FIG. FIG. 3 is a time chart showing the operation of the wireless communication system 1 according to the first embodiment of the present invention. The wireless device 2 transmits a modulated signal obtained by modulating a carrier signal with a mixed signal obtained by mixing a voice signal and a tone signal as a radio wave.

At time t11, the press switch or the like of the wireless device 2 is turned off, the mixing of the tone signal and the voice signal is finished as described above, and the transmission of the tone signal is finished (tone signal transmission is cut off). At the same time as this, the radio 3
Detects the disconnection of the tone signal from the wireless device 2. Then, at time t12, the wireless device 3 recognizes disconnection of the tone signal from the wireless device 2 and controls the amplifier 114 to cut off (mute) the audio output. In this way, the time difference T11 (t11
To t12) occur because the tone signal transmission disconnection from the wireless device is reliably detected. During this recognition period,
The wireless device 3 receives only the carrier signal (silence) from the wireless device 2, and the speaker outputs silent sound. Then, at time t13, the wireless device 2 ends the transmission of the carrier signal as described above. The time difference T12
(T11 to t13) corresponds to the predetermined time.

As described above, according to the present embodiment, when the wireless device 2 finishes the transmission, it first interrupts the transmission of the tone signal, and then the carrier signal for a predetermined time set for the tone signal recognition period of the wireless device or more. Since only the carrier signal is transmitted and then the carrier signal is cut off, the wireless device 3 receives only the carrier signal from the wireless device 2 during the period in which the transmission of the tone signal is recognized, and noise from the outside is received. Is not received, the voice output can be cut off (muted) without outputting noise to the user, and the tone signal transmission disconnection can be surely recognized. It is preferable that the difference between the times t12 and t13 is small.

Next, the operation of the second embodiment of the present invention will be described with reference to FIG. The present embodiment is a wireless communication system 11 that communicates via a relay station. The reason why the wireless communication is performed via the relay station is to widen the communication area. Note that, as in the conventional technique, in FIG.
A case will be described in which the transmission is performed from the mobile station to the wireless device 3 via the relay station 8. FIG. 4 is a time chart showing the operation of the wireless communication system 11 according to the second embodiment of the present invention. The wireless device 2 transmits a modulated signal obtained by modulating a carrier signal with a mixed signal obtained by mixing a voice signal and a tone signal as a radio wave. Further, the relay station 8 takes out a voice signal from the radio wave from the radio device 2, mixes a new tone signal with the voice signal, modulates a new carrier signal with the mixed signal, and transmits the modulated signal to the radio device 3. There is.

At time t21, the press switch or the like of the wireless device 2 is turned off to end the mixing of the tone signal and the voice signal as described above, and the transmission of the tone signal is terminated (tone signal transmission is terminated). At the same time as this, the relay station 8
Detects the disconnection of the tone signal from the wireless device 2. Then, at time t22, the relay station 8 recognizes the disconnection of the tone signal from the wireless device 2 and ends the transmission of the tone signal to the wireless device 3. The time difference T21 (t21 to t22) thus occurs in order to reliably detect the disconnection of the tone signal from the wireless device. Note that during this tone signal recognition period (T21), the relay station 8 receives only the carrier signal (silence) from the wireless device 2, but since it is during the tone signal recognition period, the relay station 8 receives the tone signal. It is transmitting to the wireless device 3. Almost at the same time, the wireless device 3 detects the disconnection of the tone signal from the relay station 8. And time t23
Then, the wireless device 3 recognizes the disconnection of the tone signal from the relay station 8 and controls the amplifier 114 to cut off (mute) the audio output. Thus, the time difference T22 (t22 to t2
The reason 3) occurs is to reliably detect disconnection of the tone signal from the relay station. During this tone signal recognition period, the wireless device 3 receives only the carrier signal (silence) from the relay station 8, and the speaker outputs silence. Then, at time t24, the wireless device 2 ends the transmission of the carrier signal as described above. The time difference T2
3 (t21 to t24) corresponds to the predetermined time. Then, at time t25, the relay station 8 detects the transmission stop of the carrier signal from the wireless device 2 and ends the transmission of the carrier signal to the wireless device 3. Thus, the time difference T24 (t24 to t2
The reason 5) occurs is to reliably detect the disconnection of the carrier signal from the wireless device. The relay station 8 may continue to transmit the carrier signal even if it recognizes that the carrier signal has been transmitted. Further, although the predetermined time is set to be longer in the present embodiment, in the present embodiment, the relay station 8 is provided with the carrier signal detection period for surely detecting the carrier signal transmission interruption, and therefore, in practice, the predetermined time is set. The time may be at least longer than the tone signal recognition period (T21) of the relay station. On the other hand, when the carrier signal detection period is not provided, the predetermined time is the sum of the tone signal recognition period of the relay station and the tone signal recognition period of the wireless device (T2) as in the present embodiment.
1 + T22) or more, from time t21 to time t
Noise can be prevented over 23 levels.

As described above, according to the present embodiment, when the wireless device 2 finishes the transmission, it first interrupts the transmission of the tone signal, and then the carrier for the predetermined time set for the tone signal recognition period of the relay station 8 or longer. Since only the signal is transmitted and then the carrier signal is disconnected, the relay station 8 receives only the carrier signal from the wireless device 2 during the period in which it recognizes the disconnection of the tone signal from the wireless device 2. However, since the tone signal is being recognized, the tone signal is transmitted to the wireless device 3 together with the carrier signal, noise from the outside is not received and transmitted to the wireless device 3, and the wireless device 3 Relay station 8
During the period in which the transmission of the tone signal from the terminal is recognized, the relay station 8
Therefore, only the carrier signal from is received, and noise from the outside is not received. Therefore, the radio 2
After the transmission of the tone signal is stopped (time t21), until the wireless device 3 cuts off (mutes) the voice output (time t23), external noise is not received, and noise is output to the user. Without this, the audio output can be cut off (muted), and the tone signal transmission cutoff can be reliably recognized. Further, it is possible to suppress the noise output only by improving the program of the wireless device without improving the relay station.

[0030]

As described in detail above, according to the present invention, at the end of transmission by the transmitting radio, the tone signal is first cut off, and then the tone signal is recognized by the radio or relay station. By transmitting only the carrier signal (silence) for a predetermined time set for the period or more or for the sum of the tone signal recognition periods of the wireless device and the relay station, and then cutting off the carrier signal, the receiving-side wireless device It is possible to cut off (mute) the audio output without outputting noise from the end of the transmission (tone signal transmission cutoff) to the cutoff (mute) of the audio output after the transmitting radio device ends the transmission. At the same time, the original purpose of surely recognizing the disconnection of the tone signal transmission can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of wireless devices 2 and 3.

FIG. 2 is a flowchart showing the processing of a microcomputer 102.

FIG. 3 is a time chart showing the operation of the wireless communication system 1 according to the first embodiment of the present invention.

FIG. 4 is a wireless communication system 11 according to a second embodiment of the present invention.
Time chart showing the operation of.

FIG. 5 is a schematic diagram of a wireless communication system 1 without a relay station.

FIG. 6 is a time chart showing the operation of the conventional wireless communication system 1.

FIG. 7 is a schematic diagram of a wireless communication system 11 via a relay station.

FIG. 8 is a time chart showing the operation of the conventional wireless communication system 11.

[Explanation of Codes] 2, 3 ... Radio 8 ... Relay station 102 ... Microcomputer 104 ... Carrier oscillator 105 ... Tone oscillator 116 ... Frequency comparator

Claims (3)

[Claims] 1. A plurality of wireless devices for transmitting and receiving a carrier signal by modulating a voice signal and a tone signal, the wireless device having tone signal detecting means for detecting the tone signal when receiving, In the wireless communication system having a tone signal recognition period from when the tone signal detecting means detects the transmission interruption of the tone signal to when the output of the voice signal is cut off, the wireless device transmits the tone signal at the end of transmission. A wireless communication system, comprising: a transmitting unit that suspends transmission of the carrier signal after a lapse of a predetermined time after the transmission is interrupted, the predetermined time being equal to or longer than the tone signal recognition period. 2. A tone signal detection device that has a plurality of radios that modulate a carrier signal with a voice signal and a tone signal and transmit / receive through the relay station, the relay station detecting the tone signal at the time of relaying. A tone signal detecting means, the tone signal detecting means having a tone signal recognition period from the detection of the tone signal transmission interruption to the end of the relay of the voice signal, A wireless communication system, comprising: a transmitting unit that cuts off transmission of the tone signal and then cuts off transmission of the carrier signal after a predetermined time elapses, and the predetermined time is equal to or longer than the tone signal recognition period. 3. A tone signal from a radio device for transmitting a carrier signal, wherein the radio signal is modulated by a voice signal and a tone signal and transmitted and received through a relay station. The first tone signal detecting means for detecting the interruption of the transmission of the tone signal from the radio device which performs the transmission until the end of the relay of the voice signal. The wireless device having the first tone signal recognition period and performing reception has second tone signal detection means for detecting the tone signal from the relay station at the time of reception, and the second tone signal detection means In a wireless communication system having a second tone signal recognition period from detection of a tone signal transmission interruption from the relay station to interruption of an output of a voice signal, a radio device performing the transmission, when transmission is completed, After disconnecting the tone signal A transmission means for interrupting the transmission of the carrier signal after a lapse of a predetermined time is provided, and the predetermined time is equal to or more than a sum of a first tone signal recognition period of the relay station and a second tone signal recognition period of the wireless device. A wireless communication system characterized by the above.