JPH08162982A - Wireless receiver and communication method using wireless receiver - Google Patents

Abstract

PURPOSE: To automatically retrieve a free channel. CONSTITUTION: When a frequency retrieval switch 7 is turned on, a control part 3 automatically and successively sets the channel that the group set by a group setting part 5 has to a reception part 2 at a prescribed time interval. When the reception level of the reception part 2 is a prescribed level or below or the level is so small that it can be neglected, the channel set to the reception part 2 or a free channel is displayed on a display part 10. During the operation, a voice output part 4 is controlled by the control part 3 so as not to output voice from this output part 4. The reception part 2 receives the radio wave inputted from a reception antenna 1 in accordance with the antenna input sensitivity and squelch sensitivity set by an antenna input sensitivity setting part 8 and a squelch sensitivity setting part 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless receiver (hereinafter referred to as a receiver) used for one-way communication such as a wireless microphone system, and a communication method thereof.

[0002]

2. Description of the Related Art In a unidirectional communication system such as the one described above, for example, a wireless microphone system, the microphone side is a transmission-only device and the receiver side is a reception-only device. Therefore, when the communication is performed, the communication is performed using the frequency selected by the user. At this time, if similar wireless microphone systems are used in the vicinity, depending on the frequencies used in each other's system. May cause radio wave interference such as co-channel interference, adjacent channel interference, and intermodulation interference. In a general bidirectional wireless communication type wireless device or the like, by performing multi-channel access (MCA) wireless communication, an unused frequency, that is, an empty channel is automatically searched and the empty channel is used. Although the above communication can be performed without radio interference, the MCA wireless communication cannot be performed in the one-way communication method such as the wireless microphone system.

Therefore, in order to avoid the above-mentioned radio wave interference, a wireless microphone system is generally provided with, for example, a receiving antenna on the receiver side having an input sensitivity attenuation function or by adjusting the squelch sensitivity.
Removes noise caused by radio interference from other systems.
However, these methods have almost no effect on the interference from other systems used in an extremely close area, and further reduce the input sensitivity more than necessary, or require squelch sensitivity. If it is raised above the above, there is a problem that the use area of the own system becomes extremely small. Further, even if the noise due to the radio interference from the other system in the own system can be removed by these methods, the radio interference to the other system cannot be prevented.

As a method for solving the above problem, conventionally, there is a method of searching for an empty channel in advance on the receiver side and then performing communication using the searched empty channel.
That is, a receiver capable of receiving all frequencies assigned to the wireless microphone is prepared, and the reception frequencies of this receiver are manually adjusted (tuned) one by one. At this time, if some radio wave is received, that is, if some voice is heard (from the speaker of this receiver), the frequency is in use, while if no radio wave is received, that is, (this receiver If no sound is output (from the speaker), it is judged that the frequency is not used, that is, an empty channel. Then, by performing communication using the frequency determined not to be used, that is, a free channel, it is possible to perform communication between the self system and the other system as described above without giving mutual interference.

[0005]

However, as in the above-mentioned prior art, the reception frequencies of the receiver are manually adjusted one by one, and each time the frequency, that is, the usage status of each channel is judged to determine the availability. Finding a channel is very cumbersome and takes a very long time.

Further, in the above-mentioned prior art, the user,
That is, since the human being determines the usage status of each channel by listening to the sound (hearing from the speaker of the receiver) with his / her ear, when the channel in use is in the silent state, the channel in use is set as an empty channel. May be judged. In addition, when multiple channels are in an interference state, only noise such as beat waves may be heard even if voice communication is performed. Therefore, as described above (audible from the speaker of the receiver) It is difficult to judge whether these channels are in use or free channels only by recognizing. For this reason, the above-mentioned conventional technique has a problem that it lacks certainty in searching for a free channel.

According to the present invention, when searching for an empty channel, it is automatically determined based on the reception level of the received electric wave whether the electric wave is in use, that is, whether it is an empty channel. However, it is an object of the present invention to provide a receiver capable of surely searching for a free channel. It is also an object of the present invention to provide a communication method capable of preventing radio wave interference by performing communication using an empty channel searched by this receiver.

[0008]

The receiver of the first invention comprises:
A receiver that receives radio waves of a set frequency, a controller that sequentially sets a plurality of frequencies to the receiver at predetermined time intervals, and a receiver that receives radio waves of the frequency set by the controller. Determining means for determining whether or not the reception level of the receiving section is less than or equal to a predetermined level when receiving at, and the determining means determines that the reception level of the receiving section is at or below the predetermined level. And an output unit for outputting frequency information indicating the frequency set in the receiving unit at that time.

The receiver of the second invention is the receiver of the first invention, wherein the plurality of frequencies are divided into a predetermined group, and the group setting for setting the group to the control unit. And the control unit is configured to sequentially set the frequencies of the set group to the receiving unit at the predetermined time intervals.

The receiver of the third invention is characterized in that, in the receiver of the first or second invention, a display section for displaying the frequency information output from the output section is provided. .

The receiver of the fourth invention is the receiver of the first, second or third invention, further comprising receiving sensitivity setting means for setting the receiving sensitivity of the receiving section, and the receiving section is set. Further, it is characterized in that it is configured to receive the radio wave according to the reception sensitivity.

The receiver of the fifth invention comprises the first, second and third receivers.
Alternatively, in the receiver of the fourth invention, squelch sensitivity setting means for setting the squelch sensitivity of the receiving section is provided, and the receiving section is configured to receive the radio wave according to the set squelch sensitivity. It is a feature.

A receiver of the sixth invention is the receiver of the first, second, third, fourth or fifth invention, and outputs a sound generated based on the radio wave received by the receiving section. A voice output control is provided for controlling the voice output unit such that the voice output unit does not output the voice when the control unit sets the frequency for the receiving unit. It is characterized by comprising means.

According to a seventh aspect of the communication method, in the receiver of the first, second, third, fourth, fifth or sixth aspect, the frequency indicated by the frequency information output from the output section is used. And wireless communication is performed.

[0015]

According to the first aspect of the invention, the control section sequentially sets a plurality of frequencies to the receiving section at predetermined time intervals, and the receiving section receives the radio wave of the set frequency. And
When the determination unit determines that the reception level of the reception unit is equal to or lower than a predetermined level, for example, a level that can be ignored, the frequency information indicating the frequency set in the reception unit is output from the output unit. That is, the output section automatically outputs the frequency at which only a negligibly low level radio wave exists (so-called unused frequency), that is, frequency information indicating an empty channel.

According to the second invention, each group has at least one frequency, and these groups are set in the control section by the group setting section. Then, the control unit sequentially sets the frequencies of the set group to the receiving unit at predetermined time intervals, and the receiving unit receives the radio wave of the set frequency. As a result, the unused frequency among the frequencies of the set group, that is, the frequency information indicating the empty channel of the set group is output from the output unit as in the first aspect of the invention.

According to the third invention, the display section displays the frequency information output from the output section.

According to the fourth invention, the receiving section receives the radio wave according to the receiving sensitivity set by the receiving sensitivity setting means.

According to the fifth invention, the receiving section receives the radio wave according to the squelch sensitivity set by the squelch sensitivity setting means.

According to the sixth aspect, the sound generated based on the radio wave received by the receiving section is output from the sound output section. Then, when the control unit sets the frequency for the receiving unit, that is, when searching for an empty channel, the audio output control unit controls the audio output unit so that the audio output unit does not output the audio. Control.

According to the seventh invention, communication is performed using the frequency indicated by the frequency information output from the output section in the receiver of the first, second, third, fourth, fifth or sixth invention. By performing the above, communication is performed using a frequency that is not used in another system, that is, a free channel.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a receiver according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a receiver of a wireless microphone system. Generally, the FM modulation method is used for communication of the wireless microphone system. For example, in the wireless microphone system of the 800 MHz band, 30 frequencies, that is, 30 channels are allocated at equal frequency intervals as the communication frequency. ing. The receiver of this embodiment adopts the FM modulation method, and can receive all the radio waves of the 30 channels by switching the reception frequencies.

Further, these 30 channels are divided into a plurality of groups, for example, 1 to 6 channels are combined into one group. In addition,
This group is a group of channels that are in a relationship in which radio waves do not interfere with each other when a plurality of wireless microphone systems are simultaneously used in the same area. That is, when a plurality of wireless microphone systems are used at the same time in the same area, by using different channels in the same group in each system, it is possible to prevent radio wave interference between the systems.

When communication is performed with the receiver shown in FIG.
That is, a case where the receiver receives a radio wave transmitted from a microphone (not shown) will be described. First, the group and channel are set from the group setting unit 5 and the channel setting unit 6 to the control unit 3 which is constituted by, for example, a microcomputer. Control unit 3
Transmits the set group and channel information to the receiving unit 2. The receiving unit 2 receives the information of the group and the channel, sets the reception frequency, and receives the radio wave of this reception frequency via the reception antenna 1.

At this time, if the receiving section 2 receives a radio wave, the receiving section 2 transmits a signal of "radio wave present" to the control section 3, and the control section 3 receiving this signal causes the voice output section. 4 to the voice output permission signal. As a result, the sound generated based on the radio wave received by the reception unit 2 is output from the sound output unit 4 to the outside. The antenna input sensitivity setting unit 8 and the squelch sensitivity setting unit 9 set the antenna input sensitivity and the squelch sensitivity for the receiving unit 2, and the receiving unit 2 follows the set antenna input sensitivity and squelch sensitivity. Receive radio waves.

This receiver receives the radio wave transmitted from the microphone as described above. As a channel used for this communication, a channel not currently used by another system, that is, an empty channel is searched. It is also something to do. Here, the procedure for searching for the above-mentioned empty channel using this receiver and the operation of this receiver will be described with reference to the flowchart shown in FIG.

First, the power of the microphone is turned off to stop the transmission of radio waves from the microphone to the receiver, and then the frequency search switch 7 connected to the control unit 3 is turned on (step S2). As a result, the control unit 3
From the state of receiving radio waves, it enters the state of free channel search. At the same time, the information of the group Gm ₀ and the channel Cn ₀ set when the frequency search switch 7 is turned on in step S2 is stored in the memory (not shown). Further, a voice output non-permission signal is transmitted from the control unit 3 to the voice output unit 4 so that the voice output unit 4 does not output the voice, whereby the voice output unit 4 does not output the voice (step S4).

Next, the plurality of groups Gm (m =
Of the 1, 2, ..., M), the lowest numbered group G ₁ is set in the receiver 2 as an initial setting group (step S6). And this set group G
Channel C of m (group G ₁ at this point)
Of n (n = 1, 2, ..., N), for example, the channel C ₁ having the lowest frequency is set in the receiving unit 2 (step S8).

The radio wave of the set channel C ₁ is received by the receiver 2 (step S10), and the reception level (strength) of the receiver 2 that receives the radio wave of the channel C ₁ is a predetermined level, For example, it is determined whether or not the level is below the negligible level V (step S12). As described above, the FM receiver
Since the modulation method is adopted, the reception level of the receiving unit 2 is the level of the carrier wave of the received radio wave (carrier level).
Is proportional to

[0030] Here, the reception level of the reception section 2 receives a radio wave of the channel C ₁ is, when it is below the level V enough to be above negligible, considered the channel C ₁ is a vacant channel C _OK, The channel information representing the channel C ₁ is temporarily stored in the memory (step S14). On the other hand, when the reception level is higher than the negligible level V, the channel C ₁
Is considered to be the channel C _NO in use,
Channel information representing this channel C ₁ is temporarily stored in the memory (step S16).

The operations from step S10 to step S14 or S16 are sequentially repeated until it is determined whether or not all channels Cn of the group G ₁ are empty channels (step S1).
8, S20).

When it is judged whether or not all the channels Cn of the group G ₁ are free channels, the group number is automatically updated to the next group G ₂ (step S22). And this time,
A search for an empty channel in this group G ₂ is performed, that is, the operations from step S8 to step S20 are repeated. This step S8 to step S20
The operations up to are repeated for all groups Gm, that is, free channels are searched for for all groups Gm (steps S24 and S26).

When the search for empty channels in all the groups Gm is completed, the empty channels C _OK stored in step S14 are displayed on the display unit 10. This display method is as follows. First, the group Gm ₀ stored in step S4 and this group Gm ₀
The empty channel C _OK within is displayed (step S28).

For the groups Gm other than this group Gm ₀ , when it is desired to confirm the empty channel C _OK ,
The group setting unit 5 sets (changes) a desired group number (step S30). As a result, this set (changed) group Gm and the empty channel C _OK in this group Gm are displayed (step S32). Furthermore, when it is desired to confirm an empty channel in another group Gm, the above step S
30 and S32 are repeated.

When the confirmation of the empty channel C _OK of the desired group Gm is completed, the frequency search switch 7 is turned off (step S34). As a result, the group Gm ₀ and the channel Cn ₀ stored in the memory in step S4 are set in the receiving section, and an audio output permission signal is transmitted to the audio output section 4 (step S36), that is, this The receiver returns to the communication state of receiving the electric wave of the microphone.

Then, as described above, the empty channel C _OK for each group Gm is searched, and the empty channel C _OK in each group Gm is displayed on the display unit 10.
After confirming, the group Gm and the empty channel C _OK (channel Cn) displayed on the display unit 10 in step S28 or S32 are received by the receiving unit 2 from the group setting unit 5 and the channel setting unit 6 via the control unit 3. Set to. Also on the microphone side, the group Gm and the empty channel C _OK set in the receiving unit 2 are set as the group and the channel, and the power of the microphone is turned on. As a result, the communication using the group Gm and the empty channel C _OK is performed, that is, the communication can be performed between the own system and the other systems without giving interference to each other.

As described above, this receiver can automatically search for an empty channel C _OK in the desired group Gm. And this free channel C _OK
2), that is, the operation of the flowchart shown in FIG. 2, is automatically performed by the control unit 3, so that the empty channel C _OK can be searched at a very high speed. A program for operating the control unit 3 according to the flowchart shown in FIG. 2 is stored in the memory.

Further, in this receiver, in the above-mentioned empty channel search state, whether or not the channel Cn received by the receiving unit 2 is the empty channel C _OK ,
The determination is made based on the reception level of the receiver 2, that is, the level of the carrier wave of the radio wave. Therefore, even when only a carrier wave having a level that cannot be ignored is received, that channel Cn
Can be determined to be in use, that is, unlike the above-mentioned related art, it is possible to reliably search for an empty channel C _OK regardless of whether or not the received radio wave contains voice.

The retrieved free channel C _OK is
Since it is displayed on the display unit 10 together with the group Gm for each group, the user can check the available channels C _OK that can be used in the same area at a glance.

Further, it is judged whether or not there is an empty channel C _OK by judging the reception level of the reception unit 2 which has received the radio wave according to the antenna input sensitivity and the squelch sensitivity setting unit 8 and the squelch sensitivity setting unit 9. It is carried out based on. Therefore, by setting the antenna input sensitivity and the squelch sensitivity when actually performing communication, a search for an empty channel C _OK according to the installation status of this receiver is performed.

When searching for an empty channel C _OK , the control unit 3 controls the audio output unit 4 so that the audio generated from the radio wave received by the receiving unit 2 is not output to the outside. . Therefore, the user does not feel uncomfortable during the search for the free channel due to the above-mentioned sound that can be called noise during the search for the free channel.

In the present embodiment, the in-use channel C stored in the memory in step S16 of FIG.
_Although the processing of _NO has not been particularly described, the in-use channel C _NO may be configured to be displayed on the display unit 10 like the empty channel C _OK . If it is not necessary to store the busy channel C _OK , step S16 may be omitted.

Further, in this embodiment, all the groups Gm
For, is configured so as to search for the free channel C _OK, a particular group Gm, for example for the group Gm set by the group setting unit 5 only, may be configured to search for the vacant channel C _OK . With this configuration, it is possible to efficiently search for a free channel C _OK in the desired group Gm in a short time.

Furthermore, although a single receiver has been described in this embodiment, this embodiment can be similarly applied to a diversity receiver as shown in FIG. This diversity receiver is obtained by adding another antenna 1a and a receiving section 2a to the single receiver shown in FIG. 1, and the antenna input sensitivity setting section 8 and the squelch sensitivity are added to the added receiving section 2a. The configuration is such that the antenna input sensitivity and the squelch sensitivity can be set from the setting unit 9. The output of the receiving unit 2a is connected to the audio output unit 4.

The diversity receiver configured as described above outputs either the output of the receiving section having the higher receiving level among the receiving sections 2 and 2a receiving the radio waves via the antennas 1 and 1a, or either one of them. When the radio wave can only be received by the receiving section of, the output of the receiving section of the person who received the radio wave,
It is treated as a received signal. That is, in this diversity receiver, when the reception levels of both of the receiving units 2 and 2a are both equal to or lower than the predetermined level V,
That is, when the level is so small that it can be ignored, it is determined that the channel set in each receiving unit 2, 2a at that time is an empty channel. Other than this, it is the same as the single receiver described above, and thus detailed description thereof is omitted.

[0046]

The receiver of the first aspect of the invention is configured so that frequency information indicating an unused frequency, that is, a free channel, of a plurality of frequencies is automatically output. With this configuration, it is possible to search for a free channel at a higher speed than manually searching for a free channel as in the conventional case.

Further, in the first aspect of the invention, the judgment as to whether or not there is an empty channel is made according to the size of the reception level, for example whether or not the reception level is negligible. Is configured to. With this configuration, for example, even when only a carrier wave of a certain level or higher is received, it can be determined that the radio wave (channel) is in use, that is,
There is an effect that it is possible to distinguish between a channel in use and an empty channel regardless of whether or not the received radio wave contains voice. Therefore, unlike the prior art, a channel that is in use in a silent state, a channel that is in an interference state, or the like is not mistakenly determined to be an empty channel.

The receiver of the second aspect of the invention is configured such that not all channels are searched for empty channels, but empty channels are searched for within the range of channels included in the group set by the group setting section. Has been done. With this configuration, there is an effect that a free channel can be searched efficiently in a shorter time.

The receiver of the third aspect of the invention is configured so that the frequency information indicating an empty channel is displayed on the display section. With this configuration, there is an effect that the user can visually check the information about the vacant channels.

In the receiver of the fourth aspect of the invention, the receiving section is configured to receive the radio wave according to the receiving sensitivity set by the receiving sensitivity setting means. With this configuration, it is possible to search for an empty channel according to the reception sensitivity in the usage environment of this receiver, for example, the installation situation, by setting the reception sensitivity when actually performing communication. There is.

In the receiver of the fifth aspect of the invention, the receiving section is configured to receive the radio wave in accordance with the squelch sensitivity set by the squelch sensitivity setting means. With this configuration, by setting the squelch sensitivity when actually performing communication, it is possible to search for an empty channel corresponding to the squelch sensitivity in the usage environment of this receiver, for example, the installation condition. There is.

The receiver of the sixth aspect of the invention is configured so that the sound generated from the received radio wave is not output to the outside when searching for an empty channel. That is, since the above-mentioned sound, which may be called noise, is not output during the search for the free channel, the user does not feel uncomfortable with the above-mentioned sound.

The communication method of the seventh aspect of the invention is to perform communication by using the free channel searched by the receiver of the first, second, third, fourth, fifth or sixth aspect of the invention. By thus performing the communication using the vacant channel, there is an effect that the communication can be performed between the own system and the other system without giving radio interference to each other.

[Brief description of drawings]

FIG. 1 is a block diagram of a wireless receiver according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of an operation of searching for a free channel in the embodiment.

FIG. 3 is a block diagram of a diversity receiver in an application example of the same embodiment.

[Explanation of symbols]

 1 receiving antenna 2 receiving unit 3 control unit 4 audio output unit 5 group setting unit 6 channel setting unit 7 frequency search switch 8 antenna input sensitivity setting unit 9 squelch sensitivity setting unit 10 display unit

Claims (7)

[Claims] 1. A receiving unit that receives radio waves of a set frequency, a control unit that sequentially sets a plurality of frequencies to the receiving unit at predetermined time intervals, and a control unit for the frequency set by the control unit. Determining means for determining whether or not the receiving level of the receiving section is lower than or equal to a predetermined level when receiving the radio wave by the receiving section; An output unit that outputs frequency information indicating the frequency set in the reception unit when it is determined that the wireless receiver. 2. The plurality of frequencies are divided into a plurality of predetermined groups, a group setting unit for setting the group is provided for the control unit, and the control unit is configured to set the group. The wireless receiver according to claim 1, wherein the wireless receiver is configured to sequentially set the frequency included in the receiving unit at the predetermined time interval. 3. A display unit for displaying the frequency information output from the output unit is provided.
Or the wireless receiver according to 2. 4. The receiving sensitivity setting means for setting the receiving sensitivity of the receiving unit is provided, and the receiving unit is configured to receive the radio wave according to the set receiving sensitivity. The wireless receiver according to 1, 2, or 3. 5. The squelch sensitivity setting means for setting the squelch sensitivity of the receiving section is provided, and the receiving section is configured to receive the radio wave in accordance with the set squelch sensitivity. The wireless receiver according to 1, 2, 3 or 4. 6. A voice output unit is provided for outputting a voice generated based on the radio wave received by the receiving unit,
The audio output control means for controlling the audio output unit in a state in which the audio output unit does not output the audio when the control unit sets the frequency for the receiving unit. Item 6. The wireless receiver according to Item 1, 2, 3, 4 or 5. 7. The communication method according to claim 1, 2, 3, 4, 5 or 6, wherein wireless communication is performed by using a frequency indicated by the frequency information output from the output unit.