JP3141203B2 - Wireless transmission control system using optimal polarization direction discrimination method for radio signals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a wireless transmission control system using an optimal polarization direction discrimination method for a radio signal.

[0002]

[Prior art]

Recently, a wireless transmission control system that transmits a weak radio wave from a wireless transmitter to a wireless receiver to perform various controls has been developed.
In wireless security systems, etc., a wireless transmitter is additionally connected to the fire detector, and a wireless receiver is installed in the center. When a fire detector issues an alarm, the wireless transmitter receives an alarm signal and receives a radio wave An alert signal is transmitted to the wireless receiver side by a signal to issue an alert.

By the way, since such a wireless transmitter and a wireless receiver are usually installed in a building, they are transmitted from a transmission antenna of the wireless transmitter in a specific polarization direction (direction of the electric field surface with respect to the ground). Even if a radio signal is reflected by a wall surface, floor surface, or indoor furniture before being received by the wireless receiver, the polarization direction (polarization plane) is rotated, so that the reception efficiency is reduced and stable reception is performed. In many cases, the polarization direction of the transmitting antenna and the receiving antenna may be the same, but the polarization direction may be changed by reflection before the radio signal reaches the receiver side
If rotated 90 degrees, the reception level becomes the lowest and necessary control cannot be performed.

In order to prevent the reception efficiency from being reduced due to the rotation in the polarization direction (polarization plane), for example, as shown in FIG. 6, a horizontal polarization antenna 101 is provided on the wireless transmitter 100 side. And a vertically polarized antenna 102, and FIG.
As shown in (b), the same transmission data is alternately switched between the horizontal polarization antenna 101 and the vertical polarization antenna 102 and transmitted a plurality of times by operating a transmission switch (not shown). There is one that is received by the receiving antenna 201 in the polarization direction, and in such a configuration, even when the polarization direction of the transmission radio signal is rotated by reflection or the like,
Receiving antennas receive radio signals in both polarization directions and perform control processing using signals with a high reception level, thereby preventing an extreme decrease in reception efficiency and performing stable wireless control. .

However, in a wireless transmitter having such a configuration,
In general, a transmitter and a receiver are often used fixedly at an installation place, and once an optimal polarization direction is determined, a stable radio signal can be received thereafter. Since each time a radio signal is transmitted, a radio signal having a different polarization direction is transmitted alternately and repeatedly, so that the transmission time increases in accordance with the number of polarization directions, and as a result, current consumption increases and power consumption is reduced. Therefore, improvement has been desired.

[Problems to be solved by the invention]

The present invention proposed in view of the above circumstances, when the system is installed, a plurality of radio signals having different polarization directions are experimentally transmitted from the wireless transmitter side, and the radio signal transmitted at the receiver side is received. It is an object of the present invention to provide a wireless transmission control system in which the optimum polarization direction is determined by using the wireless transmission control system.

[0006]

[Means for Solving the Problems]

The present invention proposed to achieve the above object is a wireless transmission control system in which radio signals having different polarization directions transmitted from a wireless transmitter are received by a wireless receiver and required control is performed. In the wireless transmitter, a mode changeover switch for switching between a transmission mode and a test mode, a transmission antenna for transmitting at least two or more radio signals having different polarization directions,
Receiving an antenna switching signal, an antenna switching circuit that switches and connects the plurality of transmission antennas, and an antenna selection switch that fixedly selects any one of the transmission antennas;
When the mode switch is switched to the test mode, an antenna switching signal of a plurality of transmitting antennas is sequentially output to the antenna switching circuit, and a radio signal including data indicating a polarization direction of the switching antenna connected to the antenna is output. Signal processing for transmitting a radio signal including necessary transmission data via one of the transmission antennas selected by the antenna selection switch when the mode changeover switch is switched to the transmission mode. And a receiving unit that receives a radio signal transmitted from the transmitter side, and indicates a polarization direction by receiving the radio signal received by the receiving antenna. A demodulation unit that demodulates transmission data including data, and a reception level of a radio signal received by the reception antenna. And a signal processing unit that receives the polarization direction data and the reception level obtained by the wireless reception unit and determines the polarization direction with the highest reception level. And a display unit for displaying the polarization direction having the highest reception level determined by the signal processing unit.

According to a second aspect of the present invention, in the configuration of the first aspect, the wireless receiver further includes a counter unit having a reception counter corresponding to each of the polarization direction data. Each time a radio signal having a level equal to or higher than a predetermined level is determined by the level determining unit, a determination signal is transmitted to the reception counter corresponding to the polarization direction data to count the number of receptions, and the count value is calculated as described above. It is configured to display on the display unit.

According to a third aspect of the present invention, in the configuration of the first aspect, when the wireless transmitter selects and sets one of the transmission antennas with the antenna selection switch in the transmission mode, The signal processing unit switches and connects predetermined transmission antennas including the antenna in a predetermined order to transmit a radio signal.

[0009]

[Action]

The present invention employs a method for determining the optimal polarization direction of a radio signal. In this method, a wireless transmitter transmits at least two or more transmission antennas having different polarization directions. The radio signal containing the transmission data indicating the wave direction is transmitted at the same output level, and the other wireless receiver demodulates the radio wave signal transmitted from the transmitter side after receiving it at the receiving antenna and demodulating it. The direction data and the reception level are obtained, and the polarization direction having the highest reception level among the received radio signals is determined as the optimum polarization direction on the transmission side.

In such a wireless transmission control system of the present invention, when the wireless transmitter is switched to the test mode, an antenna switching signal is transmitted from the signal processing unit to the antenna switching circuit to sequentially switch a plurality of transmission antennas. , The wireless signals including the polarization direction data of the switching antennas are sequentially transmitted. Then, on the receiver side, the transmitted wireless signal is demodulated by the wireless receiver to sequentially obtain the polarization direction data and the reception level, and the signal processor determines the optimum polarization direction having the highest reception level and determines the polarization direction. The wave direction is displayed on the display unit. After obtaining the optimum polarization direction in this manner, an antenna having the corresponding polarization direction is selected by the antenna selection switch on the transmitter side, and the mode is switched to the transmission mode by the mode switch. Every time it is operated, only the radio signal in the optimal polarization direction is transmitted from the transmission antenna selected by the antenna selection switch.

According to the second aspect of the present invention, when a radio signal is transmitted from the wireless transmitter, the wireless reception unit of the wireless receiver demodulates the polarization direction data and determines the reception level. Is greater than a predetermined level, a count signal is transmitted to a reception counter corresponding to the polarization direction data via a signal processing unit to count up the number of receptions. When the reception of the radio signals having different polarization directions sequentially transmitted from the transmitter side in this way, the count data of each reception counter is transmitted to the display unit and displayed. Then, on the transmitter side, according to this display, the transmission antenna in the polarization direction with the largest number of receptions is selected and set by the antenna selection switch.

According to the third aspect of the present invention, when the wireless transmitter is set to the transmission mode, if a transmission antenna is selected and set by the antenna selection switch, a predetermined antenna including the antenna is set to a predetermined predetermined antenna. And sequentially transmits the corresponding radio wave signals in the polarization direction.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 illustrates a method of determining an optimum polarization direction. The procedure will be described with reference to the figure. A wireless transmitter transmits data sequentially through transmission antennas having different polarization directions. Radio signals including data indicating the polarization direction of the antenna are sequentially transmitted at the same output level. The wireless receiver sequentially receives and demodulates the transmitted radio signal to obtain polarization direction data and a reception level. Then, the polarization direction of the radio signal having the highest reception level among the received radio signals is determined as the optimal polarization direction.

After the optimum polarization direction on the transmitter side is determined on the receiver side, stable reception can be performed by transmitting only the radio signal in the optimum polarization direction from the transmitter side. (Refer to steps 100 to 103 in FIG. 1). That is, in the present invention, while the polarization direction of the receiving antenna is fixed, the radio signal whose polarization direction is sequentially changed is transmitted from the transmitting antenna at the same output level,
In the other wireless receiver, the receiving antenna determines the polarization direction having the highest reception level, and thereby determines the optimal polarization direction including the rotation of the polarization direction in the propagation path of the radio signal.

FIG. 2 shows a configuration of a wireless transmission control system using the above-described optimal polarization direction discriminating method. In the figure, reference numeral 1 denotes a wireless transmitter, and 2 denotes a wireless receiver.

The wireless transmitter 1 includes a transmission switch 10c for transmitting a radio signal, a mode switch 10a for switching between a transmission mode for normal transmission and a test mode for determining an optimal polarization direction, and a vertical polarization switch. A wave antenna TA1 and a horizontally polarized antenna TA2, an antenna switching circuit 12 for switching and connecting these transmission antennas TA1 and TA2,
Wireless transmission unit 11 that generates a radio signal to be transmitted from 2
An antenna selection switch 10b for fixedly selecting one of the transmission antennas TA1 or TA2, a ROM 13a storing a signal processing program and the like, and a memory unit 13 having a RAM 13b for temporarily storing data and the like, and each unit. And a signal processing unit 10 for performing the above signal processing.

When the transmission switch 10c is operated in a state where the mode changeover switch 10a is switched to the test mode, the signal processing unit 10 alternately outputs the respective antenna changeover signals to the antenna changeover circuit 12, and performs the changeover connection. While sequentially transmitting radio signals including the polarization direction data of the transmission antennas TA1 or TA2.
a is switched to the transmission mode and the transmission switch 10c
Is operated, an operation of transmitting a radio signal in a certain polarization direction via one transmission antenna TA1 or TA2 selected by the antenna selection switch 10b is performed.

The other wireless receiver 2 receives a radio signal transmitted from the transmitter 1 and receives a radio signal received by the reception antenna RA. A wireless receiving unit 21 including a demodulation unit 21a for demodulating the signal and a reception level discrimination unit 21b for discriminating a reception level of a radio signal received by the reception antenna RA;
A signal processing unit 20 that receives the polarization direction data and the reception level obtained by the wireless reception unit 21 and determines the polarization direction of the highest reception level, and a polarization of the highest reception level obtained by the signal processing unit. A display unit 22 for displaying a direction. Reference numeral 23 denotes a memory unit having a ROM 23a that stores a processing program and the like and a RAM 23b that temporarily stores processing data and the like, and 24 is a unit for transmitting a control signal to a separately installed control device by a received radio signal. I / O port.

Next, the operation of the wireless transmission control system having the configuration shown in FIG. 2 will be described with reference to the operation time charts of the transmitter 1 shown in FIGS. 3 (a) to 3 (d). I do. The mode is switched to the test mode by operating the mode changeover switch 10a, and the transmission switch 10c is operated. In accordance with a program stored in the ROM 13a, the signal processing unit 10 transmits an antenna switching signal to the antenna switching circuit 12, alternately switches and connects the transmitting antennas TA1 and TA2, and sets a polarization direction corresponding to the connected transmitting antenna. The transmission data including data (a data signal indicating vertical polarization or horizontal polarization) is generated and transmitted to the wireless transmission unit 11. The wireless transmission unit 11 receives the transmission data including the polarization direction data, and modulates a radio wave signal obtained by modulating a high-frequency carrier with the transmission antenna TA connected by the antenna switching circuit 12.
The data are alternately transmitted from TA1 and TA2 (see FIGS. 3A and 3B). On the other hand, on the wireless receiver 2 side, the radio signal sequentially transmitted from the transmitter 1 side is received by the wireless receiving unit 21 via the receiving antenna RA, and the demodulation unit 21a demodulates the polarization direction data and receives the radio wave signal. The signal level received by the level determination unit 21b is determined, and the polarization direction data and the reception level are transmitted to the signal processing unit 20 one by one. The signal processing unit 20 receives the polarization direction data of the series of radio signals and the reception level, determines the polarization direction having the highest reception level, transmits the polarization direction data to the display unit 22, and transmits the polarization direction data to the display unit 22. Show directions.

As described above, when the optimum polarization direction (vertical or horizontal) on the transmitter 1 side is determined on the receiver 2 side, the antenna selection switch 10 b of the wireless transmitter 1 is operated to operate the optimum polarization direction. Is selected, and thereafter, wireless transmission control is performed as follows. The transmission mode is set by operating the mode switch 10a of the wireless transmitter, and the transmission switch 10c is operated. The signal processing unit 10 transmits the antenna switching signal selected by the antenna selection switch 10b to the antenna switching circuit 12, fixes and connects the transmitting antenna TA1 (or TA2), and performs a series of operations in accordance with a program stored in the ROM 13a. The necessary transmission data is generated and transmitted to the wireless transmission unit 11. The wireless transmission unit 11 receives a series of transmission data, and modulates a radio wave signal obtained by modulating a high-frequency carrier with a transmission antenna TA1 (or TA2) connected by an antenna switching circuit 12.
(See FIGS. 3 (c) and 3 (d)). On the other hand, on the wireless receiver 2 side, the radio signal transmitted from the transmitter 1 side is received by the wireless receiving unit 21 via the receiving antenna RA, and the demodulation unit 21a demodulates the transmission data and sends it to the signal processing unit 20. Transmit. The signal processing unit 20 processes transmission data according to a program stored in the ROM 23a, and sends a control signal to a control device (not shown) via the I / O port 24 to perform necessary control.

As described above, in the wireless transmission control system of the present invention, when the system is installed, the optimum polarization direction of the transmission side is determined on the reception side by test transmission, and thereafter, only the radio signal in the optimum polarization direction is determined. Since it is transmitted from the transmitter side,
It is not necessary to alternately transmit radio signals in different polarization directions each time a radio signal is transmitted, so that it is possible to perform stable wireless transmission control with reduced transmission time and reduced power consumption.

In the above description, the receiver 2 has a configuration in which the mode set on the transmitter 1 is not particularly determined.
For example, the transmitter 1 transmits a radio signal including data indicating the test mode or the transmission mode, and transmits the radio signal to the receiver 2.
The mode is determined on the side, and the wireless receiving unit 21 and the display unit 22
May be controlled as necessary. Also, a configuration of a counter unit, which will be described later, may be configured to perform mode discrimination on the receiver 2 side and control as necessary.

FIG. 4 shows the internal configuration of a wireless receiver 2 ′ used in the system according to the second aspect of the present invention. Therefore, the same portions are denoted by the same reference numerals and description thereof will be omitted.

The counter unit 25 has reception counters 25 a and 25 b corresponding to the transmission antennas TA 1 and TA 2 provided on the transmitter 1 side, and the reception level discrimination unit 21 b of the wireless reception unit 21 in the test mode. When a radio signal of a predetermined level or more is determined, a count signal is transmitted to the reception counters 25a and 25b corresponding to the polarization direction data via the signal processing unit 20 to count up the counter. After receiving a series of radio signals, the signal processing unit 20 causes the display unit 22 to display the count data of each of the reception counters 25a and 25b together with the polarization direction data. Therefore, the reception intensity of each transmission antenna can be known by looking at the display on the display unit 22, so that it is possible to immediately determine the optimum polarization direction on the transmission side. Department
It is not necessary to perform the comparison of the reception level at 20, and the burden of signal processing is reduced.

In the above description, when the antenna selection switch 10b of the transmitter 1 is switched and set in the transmission mode, a radio signal in the same polarization direction is transmitted from one selected transmission antenna. Not limited to such a configuration,
For example, even when the vertically polarized transmitting antenna TA1 is selected by the antenna selection switch 10b, the radio wave signal is mainly transmitted in the vertical direction, but the horizontally polarized wave signal is also auxiliaryly performed a smaller number of times than the vertical direction. It is also possible to adopt a configuration in which transmission is performed (corresponding to claim 4). Such a wireless transmitter 1 can be realized with the same configuration as the wireless transmitter 1 shown in the system diagram of FIG. 2, and when the antenna selection switch 10b is switched and set, it is stored in the ROM 13a in advance. The antenna switching signal is transmitted from the signal processing unit 10 to the antenna switching circuit 12 according to the switching pattern. That is, as shown in FIGS. 5 (a) to 5 (c), when a vertically polarized antenna is selected, the same transmission data is transmitted twice by the vertically polarized antenna TA1 and the horizontally polarized antenna is transmitted. Even TA2 is made to transmit once.

According to the transmitter having such a configuration, for example, transmission of vertical polarization was optimal when the system was installed, but the optimal polarization direction changed to horizontal polarization due to room remodeling and the like. Even in such a case, stable reception can be performed on the receiver side, and the reliability of the system can be further improved.

In the above description, a configuration in which a vertical polarization antenna and a horizontal polarization antenna are provided as transmission antennas has been described. However, the present invention is not limited to such a configuration, and three or more transmissions having other polarization directions are provided. A configuration in which an antenna is provided is also possible.

[0029]

【The invention's effect】

According to the wireless transmission control system of the present invention, the optimum polarization direction of the radio signal transmitted from the transmitter is determined, and the radio signal is transmitted from the transmitter in that direction. Even if the number of signal transmissions is reduced, stable reception can be performed on the receiver side, and a wireless transmission control system in which the transmission time of a radio signal is reduced and power consumption is reduced can be provided.

According to the second aspect of the present invention, in addition to the effect of the system of the first aspect, a system in which the load of signal processing on the receiver side is reduced by a simple configuration in which a counting unit is added. Can be provided.

According to the third aspect of the present invention, in addition to the radio wave signal in the optimum polarization direction, the radio wave signal in the other polarization direction is transmitted as an auxiliary signal, so that the optimum radio wave signal is transmitted depending on the change in the surrounding environment. Even if the polarization direction fluctuates, it is possible to provide a system capable of transmitting a stable radio signal.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of a method for determining the optimal polarization direction of a radio signal.

FIG. 2 is a configuration example of a wireless transmission control system according to the present invention;

FIG. 3 is a time chart for explaining the operation of the wireless transmitter.

FIG. 4 is a block diagram showing an example of the configuration of a wireless receiver used in the system according to claim 2;

FIG. 5 is a time chart for explaining the operation of the wireless transmitter according to claim 3;

FIG. 6 is a configuration example of a conventional wireless transmission control system.

FIG. 7 is a time chart illustrating the operation of the wireless transmitter used in the system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wireless transmitter 10 ... Signal processing part 10a ... Mode changeover switch 10b ... Antenna selection switch 10c ... Transmission switch 12 ... Antenna changeover circuit 2 ... Wireless receiver 20 ... Signal processing part 21 ... Wireless receiving unit 21a: demodulation unit 21b: reception level discrimination unit 22: display unit 25: counter unit RA: reception antenna

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/38-1/58 H04B 7/00 H04B 7/02-7/12 H04L 1/02-1 / 06

Claims (3)

(57) [Claims] 1. A wireless transmission control system in which radio signals having different polarization directions transmitted from a wireless transmitter are received by a wireless receiver and required control is performed. A mode changeover switch for switching between a mode and a test mode, a transmitting antenna for transmitting at least two radio signals having different polarization directions, and an antenna switch for receiving and connecting the antenna switching signal and switching and connecting the plurality of transmitting antennas. A circuit, an antenna selection switch for fixedly selecting one of the transmission antennas, and sequentially outputting antenna switching signals of a plurality of transmission antennas to the antenna switching circuit when the mode switching switch is switched to a test mode. And contains data indicating the polarization direction of the switched-connected transmitting antenna. When the mode changeover switch is switched to the transmission mode, the radio wave signal including necessary transmission data is transmitted through one of the transmission antennas selected by the antenna selection switch. A signal processing unit, wherein the wireless receiver includes: a receiving antenna that receives a radio signal transmitted from the transmitter; and a polarization receiving unit that receives the radio signal received by the receiving antenna. A demodulation unit that demodulates transmission data including data indicating a direction; and a wireless reception unit that includes a reception level determination unit that determines a reception level of a radio signal received by the reception antenna. A signal processing unit that receives the obtained polarization direction data and the reception level, and determines a polarization direction having the highest reception level; A display unit for displaying the polarization direction having the highest reception level determined by the processing unit. 2. The wireless receiver according to claim 1, further comprising a counter unit having a reception counter corresponding to each of the polarization direction data, wherein a radio signal of a predetermined level or more predetermined by the reception level discrimination unit is provided. 2. The wireless communication system according to claim 1, wherein each time the discrimination is made, a discrimination signal is transmitted to the reception counter corresponding to the polarization direction data to count the number of receptions, and the count value is displayed on the display unit. Transmission control system. 3. When the wireless transmitter selects and sets one of the transmission antennas with the antenna selection switch in the transmission mode, the signal processing unit performs a predetermined transmission including the antenna. 3. The wireless transmission control system according to claim 2, wherein the antenna is switched and connected in a predetermined order to transmit a radio signal.