JP4876944B2 - Wireless communication system and communication method - Google Patents

Description

  The present invention relates to a wireless communication system and a communication method such as an MCA wireless system that includes a single parent device and a plurality of child devices, and enables simultaneous calls between the child devices via the parent device.

  A base unit employed in this type of wireless communication system includes a plurality of receiving circuits and one transmitting circuit, and the plurality of receiving circuits receive signals of different frequencies. On the other hand, each slave unit includes one reception circuit and a transmission circuit capable of transmitting at a plurality of frequencies.

The frequency that can be demodulated by the reception circuit of each slave unit is the transmission frequency of the transmission circuit of the master unit. The frequency that can be transmitted by the transmission circuit of the slave unit is a frequency that can be received by each reception circuit of the master unit.
A plurality of slave units transmit audio signals at different frequencies to the master unit, and the master unit that receives the audio signals from the plurality of slave units mixes the plurality of audio signals and transmits at a single transmission frequency. . Since the master unit always relays and transmits the audio signals from the plurality of slave units, and the plurality of slave units always receive the audio signal transmitted by the master unit, simultaneous communication between the plurality of slave units is possible.

In order to perform a simultaneous call without any hindrance in this type of wireless communication system, it is necessary to prevent the transmission frequencies used by each slave unit from overlapping. In order to solve this problem, a wireless system has been proposed in which the use status of each receiving unit of the master unit is transmitted as idle channel information from the master unit to the slave unit (see Patent Document 1).
JP-A-9-84098

However, in the wireless system disclosed in Patent Document 1, since the master unit transmits the vacant channel information of each receiving unit as a digital signal, in order to employ the analog wireless receiver system, an encoding circuit is provided in the master unit. It was necessary to provide a decoding circuit in the slave unit.
Also, empty channel information is transmitted every time there is a change in the usage status of each receiver in the master unit, so if the slave unit is turned on when there is no change in the usage status of each receiver unit, There was also a problem that the transmission frequency could not be set to a transmittable frequency.

  The present invention is an invention made in view of the above-described situation, and wireless communication that enables simultaneous communication between slave units without any trouble without providing an encoding circuit and a decoder in the master unit or slave unit. An object is to provide a communication system and a communication method.

In order to achieve the above object, a wireless communication system according to a first aspect of the present invention includes:
The n parent device side receiving units that respectively receive audio signals modulated at n different frequencies, and the audio signals received by the n parent device side receiving units are modulated at a single frequency and transmitted. A master unit equipped with a transmitter on the master unit side;
The slave unit receiving unit that receives the audio signal transmitted from the base unit, the frequency control unit that sets the transmission frequency from the n types of frequencies, and the audio signal that is transmitted to the base unit are set by the frequency control unit. An arbitrary number of slave units including a slave unit side transmission unit that modulates and transmits at a different frequency, and a wireless communication system comprising:
The master unit constantly detects a control signal for detecting information regarding an available frequency among the n types of frequencies from the usage status of each receiver unit on the master unit side, and a tone signal corresponding to the information detected by the control unit. Tone signal generating means for generating,
The slave unit has a table in which correspondence between the tone signal and the transmission frequency specified by the tone signal is described, and detects a transmission frequency corresponding to the tone signal given from the master unit from the table Then, the transmission frequency is set.

  The tone signal generation means modulates the tone signal with the single frequency via the parent device side transmission unit and transmits the modulated tone signal, and the child device transmits the tone signal to the child device side reception unit. You may receive by.

Further, the information regarding the vacant frequency detected by the control unit of the parent device may be information indicating one vacant frequency among the n types of frequencies.
Further, the information regarding the vacant frequency detected by the control unit of the master unit indicates information indicating one vacant frequency among the n types of frequencies and that all of the n types of frequencies are not vacant frequencies. It may be information.

In order to achieve the above object, a communication method according to the second aspect of the present invention includes:
The n master unit side receiving units that respectively receive audio signals modulated at n different frequencies, and the audio signals received by the n master unit side receiving units are modulated at a single frequency and transmitted. A master unit equipped with a transmitter on the master unit side
The slave unit receiving unit that receives the audio signal transmitted from the base unit, the frequency control unit that sets the transmission frequency from the n types of frequencies, and the audio signal that is transmitted to the base unit are set by the frequency control unit. In a communication method with an arbitrary number of slave units including a slave unit side transmission unit that modulates and transmits at a different frequency,
Detecting information related to the vacant frequency among the n types of frequencies from the usage status of each of the parent side receivers, and constantly generating a tone signal corresponding to the detected information in the parent device,
A table describing the correspondence between the tone signal and the transmission frequency specified by the tone signal is provided in the slave unit, and the slave unit sets the transmission frequency corresponding to the tone signal given from the master unit by the slave unit. The transmission frequency is set by detecting from a table.

ADVANTAGE OF THE INVENTION According to this invention, even if it does not provide an encoding circuit and a decoder in a main | base station and a subunit | mobile_unit, the radio | wireless communications system which can perform the simultaneous call between subunit | mobile_units without trouble is realizable.
Further, when the power of the slave unit is turned on, the transmission frequency is set immediately.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a wireless communication system according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing base unit 100 in FIG.
FIG. 3 is a configuration diagram showing the slave unit 200 in FIG.

As shown in FIG. 1, the wireless communication system includes a single parent device 100 and a plurality of child devices 200.
As shown in FIG. 2, the base unit 100 includes a receiving antenna 101 and, for example, four first receiving units 111, a second receiving unit 112, which are the base unit side receiving units connected to the receiving antenna 101, Third receiving unit 113 and fourth receiving unit 114, audio mixing unit 115, control unit 116, tone signal generating unit 117, squelch circuit 118, speaker 119, PTT switch (PTT) 120, A microphone 121, a transmitter 122 that is a transmitter side transmitter, a transmission antenna 123, and a memory 124 are provided.

  The receiving units 111 to 114 are connected to the receiving antenna 101 and, in an active state, demodulate modulated signals of different frequencies F1, F2, F3, and F4, respectively, and extract audio signals. These frequencies F1, F2, F3, and F4 correspond to the transmission frequency of handset 200, as will be described later, and “1”, “2”, “3”, and “4” attached to each frequency F1, F2, F3, and F4. The number “4” indicates the priority when selecting / designating the frequency.

  The audio mixing unit 115 is connected to the receiving units 111 to 114 and mixes audio signals given from the receiving units 111 to 114. The output side of the audio mixing unit 115 is connected to the transmission unit 122 and is also connected to the speaker 119 via the squelch circuit 118. Opening and closing of the squelch circuit 118 is controlled by the control unit 116. The speaker 119 outputs the audio signal given from the audio mixing unit 115 as audio.

When the control unit 116 detects that the PTT switch 120 is pressed, the control unit 116 outputs the audio signal input from the microphone 121 to the transmission unit 122.
When the control unit 116 detects that a plurality of transmission frequencies are idle, the control unit 116 selects a transmission frequency having a high priority.
The control unit 116 identifies which of the six states described below the state of the parent device 100 belongs from the usage status of each of the reception units 111 to 114 and the transmission state from the parent device 100 itself to the child device 200. A tone signal corresponding to the state is always generated from the tone signal generator 117.
A memory 124 is connected to the control unit 116, and the memory 124 describes a table indicating the correspondence between the type of tone signal and the transmission frequency specified by each tone signal.
Master device 100 can perform voice communication with slave device 200.

  The transmission unit 122 modulates the audio signal and the tone signal with a single frequency f 1 and transmits the modulated signal from the transmission antenna 123.

  As shown in FIG. 3, each slave unit 200 includes an antenna 201, a receiver 211 that is a slave unit side receiver connected to the antenna 201, a tone detector 212, a controller 213, a memory 214, A transmission unit 215 that is a slave side transmission unit, a transmission frequency setting unit 216, a microphone 217, a squelch circuit 218, a speaker 219, and a PTT switch (PTT) 220 are provided.

Receiving section 211 receives and demodulates the signal transmitted by base unit 100 at frequency f 1, and provides it to tone detecting section 212.
The tone detector 212 searches for a tone signal from the signal given from the receiver 211, detects the type of tone signal, and gives the result to the controller 213. The memory 214 connected to the control unit 213 describes a table indicating the correspondence between the type of tone signal and the transmission frequency specified by each tone signal.

The control unit 213 determines a transmission frequency based on the table in the memory 214 and causes the transmission frequency setting unit 216 to generate the determined transmission frequency.
The output side of the microphone 217 is connected to the transmission unit 215 and outputs an audio signal to the transmission unit 215.

  The control unit 213 is connected to the PTT switch 220. The control unit 213 determines whether or not the PTT switch 220 is pressed on the transmission unit 215 and notifies the transmission unit 215 of it. When the PTT switch 220 is pressed, the transmission unit 215 modulates the audio signal given from the microphone 217 with the transmission frequency generated by the transmission frequency setting unit 216, and transmits it from the antenna 201.

  The output side of the reception unit 211 is connected to the speaker 219 via the squelch circuit 218. Opening and closing of the squelch circuit 218 is controlled by the control unit 213. The speaker 219 outputs the audio signal given from the receiving unit 211 as audio.

Below, the method to set the transmission frequency of the subunit | mobile_unit 200 in cooperation with the main | base station 100 and the subunit | mobile_unit 200 is demonstrated.
FIG. 4 is a flowchart showing processing of base unit 100.
FIG. 5 is a flowchart showing processing of the slave unit 200.
FIG. 6 is an explanatory diagram of the types of tone signals generated in the base unit 100.
FIG. 7 is a diagram illustrating a relationship between a tone signal and a transmission frequency to be set.

The control unit 116 of the parent device 100 checks whether or not the receiving unit currently designated by the parent device 100 among the receiving units 111 to 114 is not in use (step S1). The currently designated receiving unit is a receiving unit designated by the tone signal currently transmitted by the parent device 100. If the receiving unit is in use (step S1: NO), it is determined whether the receiving unit 111 is not in use. If the receiving unit 111 is not in use (step S2: YES), it is determined whether or not all the receiving units 111 to 114 are in use (step S3). When all the reception units 111 to 114 are not in use (step S3: YES), it is determined whether or not the PTT switch 120 is turned off (step S4).
If the PTT switch 120 is off (step S4: YES), among the events shown in FIG. 6, the PTT switch 120 is off, no external audio signal is input, and all the receiving units 111 to 114 Is determined to be free (first state), and the tone signal generator 117 generates the tone signal fca (step S5).

  When the determination result of step S3 is that all the receiving units 111 to 114 are in use (step S3: NO), and when the PTT switch 120 is turned on in step S4 (step S4: NO), FIG. Among the events shown, the PTT switch 120 is turned on or an external audio signal is input and all the reception units 111 to 114 are free, the reception unit 112 and the reception unit 114 are in use, the reception unit 113 and the reception unit 114 are in use, or the reception unit 112 and the reception unit 113 are in use (second state), and the tone signal generation unit 117 receives the tone signal. fc1 is generated (step S6).

  If the determination result of step S2 is that the reception unit 111 is in use (step S2: NO), it is determined whether or not the reception unit 112 is in use (step S7). When the receiving unit 112 is not in use (step S7: YES), only the receiving unit 111 is used in the event shown in FIG. 6, or the receiving unit 111, the receiving unit 113, and the receiving unit 114 are in use. The tone signal generation unit 117 generates the tone signal fc2 (step S8).

  If the determination result in step S7 is that the reception unit 112 is in use (step S7: NO), it is determined whether or not the reception unit 113 is in use (step S9). When the reception unit 113 is not in use (step S9: YES), the reception unit 111 and the reception unit 112 are in use, or the reception unit 111, the reception unit 112, and the reception unit among the events illustrated in FIG. 114 is in use (fourth state), and the tone signal generator 117 generates the tone signal fc3 (step S10).

  If the determination result in step S9 is that the reception unit 113 is in use (step S9: NO), it is determined whether or not the reception unit 114 is in use (step S11). When the reception unit 114 is not in use (step S11: YES), the reception unit 111, the reception unit 112, and the reception unit 113 are in use (fifth state) among the events illustrated in FIG. And the tone signal generator 117 generates the tone signal fc4 (step S12).

  When the determination result of step S11 is that the reception unit 114 is in use (step S11: NO), the reception unit 111, the reception unit 112, the reception unit 113, and the reception unit 114 among the events illustrated in FIG. 6 are used. The tone signal fcb is generated by the tone signal generator 117 (step S13).

With the above processing, the control unit 116 classifies the state into six states, determines which state is present, and generates a corresponding tone signal.
Specifically, a state in which the PTT switch 120 is off, there is no audio input from the microphone 121, and all the reception units 111 to 114 are not used is determined as the first state, and the tone signal fca is generated. ing.

A state in which only the receiving unit 111 is not used or a state in which a plurality of receiving units including the receiving unit 111 are not used and the receiving unit 111 has the highest priority is determined as the second state. The tone signal fc1 is generated.
A state in which only the receiving unit 112 is not used, or a state in which a plurality of receiving units including the receiving unit 112 are not used and the receiving unit 112 has the highest priority is determined as the third state. The tone signal fc2 is generated.
A state in which only the receiving unit 113 is not used or a state in which a plurality of receiving units including the receiving unit 113 are not used and the receiving unit 113 has the highest priority is determined as the fourth state. The tone signal fc3 is generated.
The state where only the receiving unit 114 is not used is determined as the fifth state, and the tone signal fc4 is generated.
Further, the state where all the receiving units 111 to 114 are used is determined as the sixth state, and the tone signal fcb is generated.

  When an audio signal is input, the transmission unit 122 mixes the audio signal and the tone signal, modulates the signal with a single frequency f1, and transmits it. When no audio signal is input, the tone signal is modulated at a single frequency f1 and transmitted. Therefore, the tone signal is constantly transmitted.

The control unit 213 of the child device 200 determines whether or not the currently set transmission frequency is in a call (step S31), and when not in a call (step S31: NO), the currently set transmission frequency. Is determined to correspond to the received tone signal (step S32).
When the telephone call is in progress (step S31: YES), and when the transmission frequency corresponds to the tone signal (step S32: YES), the processing is terminated so that the setting of the transmission frequency does not change.

  When the determination result of step S32 is that the currently set transmission frequency does not correspond to the tone signal (step S32: NO), the tone signal is detected using the tone detector 212 (step S33), It is determined whether or not the detected tone signal is fca (step S34). If the detected tone signal is not fca (step S34: NO), it is determined whether or not the detected tone signal is fc1 (step S35). When the detected tone signal is fc1 (step S35: YES), the squelch circuit 218 is opened (step S36), and the transmission frequency F1 corresponding to the tone signal is generated from the transmission frequency setting unit 216 with reference to the table of the memory 214. (Step S37), the transmission frequency of the slave unit 200 is set to F1. The slave unit 200 transmits the set transmission frequency to the master unit 100, confirms that there is a change in the tone signal transmitted by the master unit 100 within a predetermined period (for example, 1 second) after the transmission, and performs processing. Exit. This confirmation process is performed to confirm that communication with the parent device 100 is normal.

  If the detected tone signal is fca (step S34: YES), the squelch circuit 218 is closed (step S38), and the transmission frequency F1 (from the transmission frequency setting unit 216 corresponding to the tone signal of fca ( (See FIG. 7) is generated (step S37), and the transmission frequency of the slave unit 200 is set to F1. The slave unit 200 transmits the set transmission frequency to the master unit 100, confirms that there is a change in the tone signal transmitted by the master unit 100 within a predetermined period (for example, 1 second) after the transmission, and performs processing. Exit.

  If the result of determination in step S35 is that the detected tone signal is not fc1 (step S35: NO), it is determined whether or not the tone signal is fc2 (step S39). When the tone signal is fc2 (step S39: YES), the squelch circuit 218 is opened (step S40), and the transmission frequency F2 corresponding to the tone signal of fc2 is generated from the transmission frequency setting unit 216 (step S41). The transmission frequency of 200 is set as F2. The slave unit 200 transmits the set transmission frequency to the master unit 100, confirms that there is a change in the tone signal transmitted by the master unit 100 within a predetermined period (for example, 1 second) after the transmission, and performs processing. Exit.

  If the result of determination in step S39 is that the detected tone signal is not fc2 (step S39: NO), it is determined whether or not the tone signal is fc3 (step S42). When the tone signal is fc3 (step S42: YES), the squelch circuit 218 is opened (step S43), and the transmission frequency F3 corresponding to the tone signal of fc3 is generated from the transmission frequency setting unit 216 (step S44). The transmission frequency of 200 is set as F3. The slave unit 200 transmits the set transmission frequency to the master unit 100, confirms that there is a change in the tone signal transmitted by the master unit 100 within a predetermined period (for example, 1 second) after the transmission, and performs processing. Exit.

  If the result of determination in step S42 is that the detected tone signal is not fc3 (step S42: NO), it is determined whether or not the tone signal is fc4 (step S45). When the tone signal is fc4 (step S45: YES), the squelch circuit 218 is opened (step S46), and the transmission frequency F4 corresponding to the tone signal of fc4 is generated from the transmission frequency setting unit 216 (step S47). The transmission frequency of 200 is set as F4. The slave unit 200 transmits the set transmission frequency to the master unit 100, confirms that there is a change in the tone signal transmitted by the master unit 100 within a predetermined period (for example, 1 second) after the transmission, and performs processing. Exit.

  If the result of determination in step S45 is that the detected tone signal is not fc4 (step S45: NO), it is determined whether or not the tone signal is fcb (step S48). When the tone signal is fcb (step S48: YES), the squelch circuit 218 is opened (step S49), and the transmission frequency from the transmission frequency setting unit 216 is invalidated (step S50).

  If the result of determination in step S48 is that the detected tone signal is not fcb (step S48: NO), the squelch circuit 218 is closed and the process is terminated.

  As described above, in this embodiment, the empty states of the transmission frequencies F1 to F4 are detected from the usage status of the reception units 111 to 114, and the tone signals fc1 to fc4, fca, and fcb as corresponding information are detected by the slave unit 200. Sent to the side. The subunit | mobile_unit 200 can set the kind of transmission frequency F1-F4 according to the kind of tone signal fc1-fc4, fca, fcb. Therefore, even if the encoding circuit and the decoder are not provided in the parent device 100 or the child device 200, simultaneous calls can be performed without any trouble. Further, the number of receiving units 111 to 114 of the parent device 100 and the number of child devices 200 do not have to match, and the number of child devices 200 under the parent device 100 can be increased.

In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible.
For example, the number of receiving units 111 to 114 is not limited to four, and may be further increased.
In addition, the control unit 116 classifies the idle state of the transmission frequency into six states and generates tone signals correspondingly, but is not limited to this. It suffices as long as one transmission frequency can be specified depending on the vacant state. By doing so, it is possible to reduce the types of tone signals.
For example, in the base unit 100 having n receiving units 111 to 114, 2 n tone signals are required to represent all available receiving unit states, but two or more are not used. Even if the receiving units 111 to 114 generate tone signals specifying one receiving unit 111 to 114, n + 1 types of tone signals (n types for specifying unused receiving units and One type indicating that all receivers are in use) is sufficient. Further, by reducing the types of tone signals in this way, it is possible to shorten the time required for searching the transmission frequency from the received tone signal on the handset device 200 side.
When determining the idle state of the transmission frequency, base unit 100 determines in order from the transmission frequency to which a high priority is given, and transmits the frequency information to slave unit 200 when at least one frequency is found. To do. When detecting the idle frequency from the tone signal, handset 200 searches in order from the tone signal corresponding to the higher priority frequency.

It is a block diagram of the radio | wireless communications system which concerns on embodiment of this invention. It is a block diagram which shows the main | base station in FIG. It is a block diagram which shows the subunit | mobile_unit in FIG. It is a flowchart which shows the process of a main | base station. It is a flowchart which shows the process of a subunit | mobile_unit. It is explanatory drawing of the kind of tone signal which generate | occur | produces in a main | base station. It is a figure which shows the relationship between a tone signal and the transmission frequency to set.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Base unit 111-114 Reception part 115 Audio | voice mixing part 116 Control part 117 Tone signal generation part 121 Microphone 122 Transmission part 200 Slave unit 211 Reception part 212 Tone detection part 213 Control part 214 Memory 215 Transmission part 216 Transmission frequency setting part 217 Microphone

Claims (5)

The n master unit side receiving units that respectively receive audio signals modulated at n different frequencies, and the audio signals received by the n master unit side receiving units are modulated at a single frequency and transmitted. A master unit equipped with a transmitter on the master unit side
The slave unit receiving unit that receives the audio signal transmitted from the base unit, the frequency control unit that sets the transmission frequency from the n types of frequencies, and the audio signal that is transmitted to the base unit are set by the frequency control unit. An arbitrary number of slave units including a slave unit side transmission unit that modulates and transmits at a different frequency, and a wireless communication system comprising:
The master unit constantly detects a control signal for detecting information regarding an available frequency among the n types of frequencies from the usage status of each receiver unit on the master unit side, and a tone signal corresponding to the information detected by the control unit. Tone signal generating means for generating,
The slave unit has a table in which correspondence between the tone signal and the transmission frequency specified by the tone signal is described, and detects a transmission frequency corresponding to the tone signal given from the master unit from the table And setting the transmission frequency. The tone signal generation means modulates the tone signal with the single frequency via the parent device side transmission unit and transmits the modulated signal.
The wireless communication system according to claim 1, wherein the slave unit receives the tone signal at the slave unit side reception unit.   The wireless communication system according to claim 1 or 2, wherein the information regarding the vacant frequency detected by the control unit of the master unit is information indicating one vacant frequency among the n types of frequencies. .   The information regarding the vacant frequency detected by the control unit of the base unit includes information indicating one vacant frequency among the n types of frequencies and information indicating that all of the n types of frequencies are not vacant frequencies. The wireless communication system according to claim 1, wherein the wireless communication system is a wireless communication system. The n master unit side receiving units that respectively receive audio signals modulated at n different frequencies, and the audio signals received by the n master unit side receiving units are modulated at a single frequency and transmitted. A master unit equipped with a transmitter on the master unit side
The slave unit receiving unit that receives the audio signal transmitted from the base unit, the frequency control unit that sets the transmission frequency from the n types of frequencies, and the audio signal that is transmitted to the base unit are set by the frequency control unit. In a communication method with an arbitrary number of slave units including a slave unit side transmission unit that modulates and transmits at a different frequency,
Detecting information related to the vacant frequency among the n types of frequencies from the usage status of each of the parent side receivers, and constantly generating a tone signal corresponding to the detected information in the parent device,
A table describing the correspondence between the tone signal and the transmission frequency specified by the tone signal is provided in the slave unit, and the slave unit sets the transmission frequency corresponding to the tone signal given from the master unit by the slave unit. A communication method characterized by detecting from a table and setting the transmission frequency.

Images