JP3353685B2 - Wireless receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to non-line receiver Ru use in a communication system in which frequency groups is set. In particular, it is suitable for use in a telecontrol device or a telemeter device of industrial equipment using the specified low-power radio equipment.

[0002]

2. Description of the Related Art Conventionally, one of a plurality of frequency channels has been selected.
2. Description of the Related Art A wireless communication system that performs communication by selecting one frequency channel is known. In such a wireless communication system, it is legally required to have a "carrier sense" function for checking whether a desired frequency channel is available and a function for transmitting a unique "call name" at the start of transmission. May have been. As an example, there is a one-way communication method or a simplex method of continuous communication using a 429 MHz band 10 mW specific low-power radio equipment.
RSTD-16A ". In this wireless communication system, 429.2500 MHz to 429.7
Up to 375 MHz, 40 waves at 12.5 kHz intervals are used.

FIG. 4 is a schematic block diagram showing a case where remote control is performed using the above-mentioned specified low power radio equipment. FIG. 4A is a block diagram of a wireless transmitting device, and FIG. 4B is a block diagram of a wireless receiving device. In the figure, 1 is an operation switch unit, 2 is a microcomputer, 3 is an RF unit, 4 is a transmitting antenna, 11 is a receiving antenna, 12 is an RF unit, 13 is a microcomputer, 14 is a relay, and 15 is a controlled device. .

[0004] In the example of the radio transmitting apparatus shown in FIG.
An operation switch for remote control also serves as a power switch. The operation switch unit 1 includes, for example, a plurality of toggle switches. The toggle switch is an operation switch having a structure in which both of the two output terminals are turned off at a neutral position and one of the output terminals is turned on at a closing position to one end or the other end. For example, when used for remote control of an on-board crane, the crane's left turn command,
The control operation of the main operation of the pair such as right turn command, boom extension / retraction, winch hoisting / lowering, boom raising / lowering, etc. is performed. In addition, a one-output terminal type tact switch may be provided to perform various operations such as mode switching and hook storage. It also has a control lever in the form of a pistol trigger, outputs an analog level operation amount called a linear output, and remotely controls a continuously changing control amount for one control command specified by the main operation. It may be controlled.

When one of the operation switches of the operation switch section 1 is turned on, the microcomputer 2 is activated by being supplied with a voltage from a power supply (not shown), and thereafter,
Even when the operation switch is turned off, the power is kept on, and when any of the operation switches is not operated for a predetermined time, for example, three seconds, the power is turned off. When the control lever is provided, the analog voltage is digitized by an A / D converter (not shown) and input to the microcomputer 2.

A microcomputer 2 having a control function
Are connected to an RF unit (high-frequency unit) 3 having a transmission function and a reception function. The microcomputer 2
At the time of reception, the result of carrier sense is input, and at the time of transmission, a modulated signal is output to the RF unit 3. When the transmission is started after the end of the carrier sense, the call name is transmitted first, and the microcomputer 2 multiplexes the on / off information of the plurality of operation switches of the operation switch unit 1 and the operation amount of the control lever to create a data signal. This is supplied to the RF unit 3 as a modulation signal. The RF unit 3 modulates a carrier with the data signal and transmits the modulated signal from the transmitting antenna 4.

[0007] In the radio receiving apparatus shown in FIG. 4 (b), the radio wave from the remote control transmitting apparatus received by the receiving antenna 11 is demodulated in the RF section 12,
Output to After the power is turned on, the microcomputer 13 repeatedly changes the setting of the receiving frequency at first after the power is turned on, and fixes the receiving frequency when detecting the radio wave from the paired transmitting device.

Next, when the received data signal is demultiplexed and the ON / OFF output of the operation switch is output to the controlled device 15 via the relay 14 and the operation amount of the control lever is also received, the drawing is shown in FIG. The data is converted into an analog output (for example, voltage or pulse width) by a D / A converter that is not used and output to the controlled device 15. In the controlled device 15, according to the on / off output of the operation switch,
Various control commands are executed, and at the same time, the operation speed of the control commands is controlled according to the operation amount of the control lever.

FIG. 5 is a flowchart for explaining the operation of the microcomputer. The flowchart on the left side of the figure is for the wireless transmission device. When it is detected in S21 that any of the operation switches has been turned on, the power is turned on. In S22, the microcomputer 2 is started up and an EEPROM (not shown)
The frequency data and the call name are read from the OM. S2
In 3, the RF unit 3 is set to the receiving operation. S2
In 4, the counter for switching the receiving frequency channel is initialized, frequency data is set in the PLL oscillation circuit in the RF unit 3, the frequency is stabilized, carrier sense is performed, and the process proceeds to S25.

In step S25, the presence or absence of a radio wave is detected, and it is determined whether or not the frequency channel of the set reception frequency is free. If not, the process proceeds to S26, where the next frequency channel is set, and
Return to 24. If the set frequency channel is free in S25, the process proceeds to S27, where the RF unit 3
To the transmission operation, set the transmission frequency data,
After the frequency is stabilized, the calling name is transmitted in S28, and in S29, data obtained by multiplexing the operation information of the operation switches and the control lever (trigger) in the operation switch unit 1 is transmitted.

The flowchart on the right side of the drawing is for the radio receiver. When the power is turned on in S31, the microcomputer 13 is started in S32. Note that the power of the wireless receiving device is usually turned on before the power of the wireless transmitting device is turned on. In S33, the frequency channel is set to the first one. S3
In 4, it is determined whether or not a signal has been received from a paired wireless transmission device. If a signal has been received, the process proceeds to S36; otherwise, the process proceeds to S35.

The same frequency group is assigned to the paired radio transmitting apparatus and radio receiving apparatus. Then, as an example, an ID code is transmitted together with the operation information, and the ID code is collated with the ID code on the receiving side. Therefore, in S34, if a frequency channel belonging to the frequency group assigned to the wireless receiving device is detected and the ID code matches, it is understood that the signal is from a paired wireless transmitting device. In S35, the next frequency channel is set in the RF unit 12, and the process returns to S34 again. S3
At 5, the operation information is received. The paired wireless transmission devices may be identified by a method other than the ID code collation.

The above-mentioned plurality of frequency channels include a case where one wave is automatically selected from all the frequency channels determined by law and a case where frequency channels are grouped from the beginning and one wave is selected from the group. May be automatically selected. If frequency channels are not grouped, it takes time to automatically select carrier sense and frequency channels. As a result, the first response of the wireless receiving device may be very slow immediately after the power of the wireless transmitting device is turned on.

In particular, as described above, when the operation switch for remote control is used also as the power switch, the response is too slow, which is inconvenient for actual use. In order to speed up the response, the communication connection state may be set even when the operation switch is not operated. However, since radio waves are constantly emitted, there is a problem that the battery life is shortened.

On the other hand, when the frequency channels are divided into groups, 40 frequency channels are divided into n groups of m waves so as not to overlap. Where m, n
Have a relationship of m × n = 40. For example, there are 10 groups of 4 waves, 8 groups of 5 waves, and the like. A wireless transmitter and a wireless receiver to be paired are set to a specific frequency group, and one of m waves in the group is automatically selected and used for communication. In this case, since the carrier sensing does not take much time, the response immediately after power-on of the wireless transmission device can be quickened.

However, if all the m-waves belonging to the frequency group assigned to the paired radio transmitter and radio receiver happen to be used by another pair near the place of use, it is assumed that the m-waves other than this frequency group are used. Even if a frequency channel is free, there is a problem that this free frequency channel cannot be used. In addition, when the same user has a plurality of pairs of wireless transmission devices and wireless reception devices, the number of frequency groups is as small as n, so that strictly, different pairs of frequency groups are supplied so as not to cause interference. Management.

[0017]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has been made to solve the above-mentioned problem by providing more frequency channels and / or more frequency channels within the range of all frequency channels allowed. with a group can be used, it is an object to provide a radio receiver that does not average response becomes extremely long due to the automatic selection of the frequency channel.

[0018]

[0019]

According to the first aspect of the present invention, there is provided a communication system in which a free channel is selected between a radio transmitting apparatus and a radio receiving apparatus which belong to the same frequency group and form a communication channel. In the radio receiving apparatus used, a product of the number of the frequency groups and the number of channels constituting the frequency group is set to be larger than the number of usable channels, and the carrier sense on the side of the radio transmitting apparatus is used. In j, the channels up to the j-th (j is an integer) in which the scanning order is higher are the highest priority channels, the selection is started from the highest priority channel, and the selection of the highest priority channel is repeated. Before the next iteration of the highest priority channel selection,
A plurality of channels are selected in order of k waves (k is an integer of 1 or more) sequentially from the (j + 1) -th channel, and signals from the paired wireless transmission devices belonging to the same frequency group are detected during the channel selection. Sometimes, the operation of selecting the channel is stopped and the channel is set as a communication channel. Therefore, more channels and / or more frequency groups can be used within the range of all allowed channels, and the average response due to automatic channel selection does not become extremely long.

[0020]

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 to 3, the procedure for setting the frequency group used in one embodiment of no line transmitting apparatus and radio receiving apparatus of the present invention. The schematic configuration of the wireless transmission device and the wireless reception device is the same as that of the conventional one shown in FIG. The operation of the microcomputer is not different from the conventional one shown in FIG. 5 as a whole, but the specific operation of selecting the carrier sense and the reception frequency is different.

[0021] Radio transmitting apparatuses belong to the same frequency group.
Select an empty channel with the corresponding wireless receiver.
Is used for communication systems that use
The number of frequency groups and the frequency groups.
The product of the number of channels to be formed is the number of available channels.
Is set to be large, and
Up to j-th (j is an integer) in which the scanning order is higher
Of the above channels are such that the channel spacing is not even
And in the carrier sense,
Scanning of said channel when a free channel is detected
And set the empty channel as the communication channel
Things. Therefore, the range of all channels allowed
More channels and / or more
Wavenumber groups can be used and intermodulation interference is reduced.
Can be done. In this wireless transmission apparatus, in the carrier sense of S23 to S25 in FIG. 5 described above, all frequency channels (hereinafter simply referred to as channels) of the frequency group assigned to this wireless transmission apparatus are determined in a predetermined scanning order. Receive in sequence. This scanning order is referred to as No. 1 to No. Expressed as 40. If an empty channel is found during the scanning, the scanning is stopped, this is determined as the transmission channel, and after S27, the transmission radio wave is fixed and fixed to this channel. Therefore, all the allowed channels can be used. In addition, No. 40
If there is a case where no empty channel is found even when scanning is performed, the transmission operation is stopped. Scanning may be started again from 1.

FIG. 1 is a diagram for explaining a selection order in a channel selection operation in one embodiment of the radio receiving apparatus of the present invention. In S33 to S35 in FIG. 5, a channel selection operation is performed. In FIG. The number attached with is a scanning number indicating the scanning order of the channel in which the above-described wireless transmission device performs carrier sensing. on the other hand,
For the channel selection operation on the wireless receiving device side, the highest priority channel is provided.

In the period (1), first, the five highest priority channels (No. 1 to No. 5) are sequentially selected. In the meantime, if the signal of the wireless transmission device to be paired can be detected,
At that point, the channel selection operation ends. If it cannot be detected, then the No. Select channel 6.
Then, when the signal from the paired wireless transmission device still cannot be detected, the next No. Instead of selecting the channel number of No. 7, the process shifts to the period of (2) and again selects the five highest priority channels (No. 1 to No. 5) sequentially.

In the meantime, if no signal from the pair of wireless transmission devices is detected, the first time the No. 7 channel is set. Similarly, the channels in the highest priority channel are sequentially and repeatedly set, and before shifting to the next cycle, the other lower channels are interposed one by one, and five priority channels (No. 1 to No. 5) are inserted. Repeat to select again. Then, the cycle of (35) is completed. The operation of selecting all channels up to 40 channels ends. During this time, upon receiving a signal from the paired wireless transmission device, the wireless reception device stops the selection operation and fixes the reception frequency. If a signal from the paired wireless transmission device cannot be received due to a temporary radio wave situation or the like, the operation is restarted from the period (1). However, if the selection operation is repeated indefinitely, the response becomes long. Therefore, the selection operation is stopped only once from the first cycle (1), and the selection operation is stopped.

By the above-described channel selection operation, many channels can be used within one frequency group, and many frequency groups can be used. In addition, the average response due to automatic channel selection does not become extremely long.

Conventionally, one frequency group is operated with, for example, five waves. However, there is little probability that any frequency can be used. Therefore, even if the above-described channel selection operation is performed, there is a high probability that a usable frequency can be found among the five highest priority channels. Even if no usable channel is found in the five highest priority channels, the initial response until the reception frequency is determined is deteriorated because all of the 40 waves are finally selected. There is no real situation where none of the channels can be used. For example, 429 MHz
Even in a place where a large number of wireless transmitting / receiving devices having a specific low power of 10 mW in a band are collected, if a channel is available in 40 waves, it can be used. Even if the automatic tuning of 40 waves is possible, the substantial response is the same as that of the conventional automatic tuning of 5 waves.

[0027] In the carrier sense of the transmitting apparatus, the reason why only the highest priority channel is not preferentially repeated as in the frequency selection operation of the receiving apparatus is that the main purpose is to start transmission early. It is not possible to predict when a channel that has once detected radio waves will be vacant. Unless it is transmitted, it cannot be received on the receiving side.
Therefore, it is possible to start transmission faster by searching for available channels one after another, rather than monitoring the highest priority channel many times over a short period and waiting for available channels. On the other hand, the receiving apparatus side does not know when the transmitting apparatus side starts transmission using an empty channel, and also sometimes cannot temporarily receive a signal from a paired transmitter, so as described above. As for the priority channel, the reception channel is preferentially selected in a short cycle.

In the above description, the channel sandwiched between the repetition of the highest priority channel is one channel at a time, but it is also possible to sandwich two or more channels continuously. For example, when two waves are interposed, (No. 1 to No. 5) are sequentially selected in the cycle of (1), and 6, N
o. 7 are sequentially selected, and N is selected in the next cycle (2).
o. 8, No. Nine channels are sequentially selected. In this way, by selecting a plurality of channels at once,
Response of a lower channel that is not the highest priority channel can be hastened.

FIG. 2 is an explanatory view of a channel used in one embodiment of no line transmitting apparatus and radio receiving apparatus of the present invention. In FIG. Are the scan numbers (No. 1 to No. 5) of the five highest priority channels described above. The channel number indicates the number of a channel used in each of the plurality of frequency groups. It should be noted that the number is shown by subtracting 6 from the channel number described in the above-mentioned standard document “RCR STD-16A”. a is the scanning number. 1
, And the scanning number N
o. Channel number corresponding to 2 is a + 3, scan number N
o. The channel number corresponding to scan number No. 3 is a + 3 + 5. The channel number corresponding to scanning number No. 4 is a + 3 + 5 + 7. The channel number corresponding to 5 is a + 3 + 5 +
7 + 9.

The above-mentioned highest priority channels in the same frequency group do not have equal channel intervals, thereby preventing intermodulation interference between the highest priority channels in the same frequency group. As a specific example, in the first frequency group, scan numbers No.
Assuming that the channel number a corresponding to 1 is 1, 429.2
5 MHz. Channel spacing is 0.0125 MHz
It is. Scan No. The channel number corresponding to 2 is 4.
429.2875 MHz, scanning number No. The channel number corresponding to 3 becomes 9 and 429.35 MH
z, scan number No. The channel number corresponding to 4 becomes 169.4432 MHz, and the scanning number No. The channel number corresponding to 5 becomes 25 and 429.55 MHz.
Becomes

Therefore, in one frequency group, not only can more channels be used within the range of all allowed channels, but also intermodulation interference is set when setting the highest priority channel in which the scanning order is prioritized. Consideration does not occur.

FIG. 3 is an explanatory diagram of channel numbers constituting a frequency group used in an embodiment of the radio receiving apparatus according to the present invention. In FIG. Is the scan number as in FIG. The first to fortieth frequency groups are arranged in the horizontal direction, and the channel numbers forming each frequency group are shown in the vertical direction in descending order of the scan numbers. The first to eighth, thirty-ninth, and fortieth groups are illustrated as frequency groups, and the other groups are omitted.

In the example shown, the total number of frequency groups is 4
0 and one frequency group is the highest priority channel 5
Waves and 35 other channels, and the combination and order of the channels are different for each frequency group. Since the channels are used repeatedly between the groups, the number of frequency groups shown in the figure is much larger than that of the conventional frequency group. However, as described with reference to FIG. 2, it is not merely used repeatedly that not only the assignment of the highest priority channel in one frequency group is devised, but also the following The decision is made in consideration of the following points. (1) Scan number No. selected first One channel is made different for each group, specifically, 1 to 40. (2) Within the highest priority group, there is no group in which three or more channels overlap between frequency groups. In addition, although broken lines are written in FIG. 3, in each frequency group, a channel having a high possibility of intermod interference in the same frequency group is arranged on a lower side of the scanning order below the broken line, The frequency of these uses is reduced.

The channel numbers constituting the frequency groups as shown in FIG.
The channel number of the assigned frequency group or the parameter designating the frequency is stored in a nonvolatile memory such as an EEPROM together with the scan number. Alternatively, a channel number or a parameter designating a frequency and a scan number for all frequency groups are stored in a non-volatile memory, and the frequency group is externally stored in E
By writing to non-volatile memory such as EPROM,
The channel number of the assigned frequency group and the scanning number thereof may be specified.

In the above description, frequency groups equal to the number of usable channels are provided. However, more frequency groups may be provided, and conversely, fewer frequency groups may be provided. You may. Also,
Although all the frequency groups can use all the channels, the number of usable channels may be smaller than this.

[0036]

[Effect of the Invention] As apparent from the above description, according to the present invention, more channels, it is possible to use more frequency groups, referred to the average response by automatic selection of Chi Yaneru it is not extremely long effective. Therefore, the present invention is suitable for use as a wireless telecontrol device for a vehicle-mounted crane, a wireless telecontrol device for industrial equipment, or a telemeter device using specific low-power wireless equipment for scanning or selecting a communication channel.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a selection order in a channel selection operation in an embodiment of a wireless reception device of the present invention.

FIG. 2 is an explanatory view of a channel used in one embodiment of no line transmitting apparatus and radio receiving apparatus of the present invention.

FIG. 3 is an explanatory diagram of channel numbers constituting a frequency group used in an embodiment of the wireless reception device of the present invention.

FIG. 4 is a schematic block diagram of a case where remote control is performed using specific low-power wireless equipment.

FIG. 5 is a flowchart for explaining the operation of the microcomputer.

[Explanation of symbols]

1 operation switch section, 2 microcomputer, 3
RF section, 4 transmitting antennas, 11 receiving antennas, 12
RF unit, 13 microcomputer, 14 relay,
15 controlled equipment

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-204242 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28 300

Claims (1)

(57) [Claims] 1. A radio receiving apparatus used in a communication system which selects an empty channel between a radio transmitting apparatus and a radio receiving apparatus which belong to the same frequency group and form a communication channel, and wherein the number of the frequency groups is The product of the frequency group and the number of channels forming the frequency group is set to be larger than the number of usable channels, and the j-th (j is an integer) in which the scanning order is higher in the carrier sense on the radio transmitting apparatus side ) Are the highest priority channels, the selection is started from the highest priority channel, and the selection of the highest priority channel is repeated, and before the next repetition of the selection of the highest priority channel, (J +
1) When a plurality of channels are selected in order of k waves (k is an integer of 1 or more) sequentially from the first channel, and signals from the paired wireless transmission devices belonging to the same frequency group are detected during the channel selection. A radio receiving apparatus, wherein the channel selection operation is stopped and the channel is set as a communication channel.