JPH0482420A - Wireless transmitter provided with interference preventing function and wireless transmission control system using the same - Google Patents

Abstract

PURPOSE:To prevent interference at a reception side from occurring by discriminating the presence/absence of the transmission of a wireless signal from the other, and starting the transmission after confirming the stoppage of the transmission of another wireless signal. CONSTITUTION:A control signal is transmitted to a monitor reception part 11 by operating a transmission switch 10a, and the reception part 11, in the case of discriminating the transmission of a wave signal with the same frequency band area as that of the wave signal desired to transmit, returns a transmission standby signal continuously to a signal processing part 10 for that period, and returns a transmission permission signal at a time when it is discriminated that the transmission is stopped. By sending a wave from a transmission part 12 after a time when the transmission permission signal is inputted, the interference at the reception side can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wireless transmitter having a confusion prevention function and a wireless transmission control system using the same.

[Prior Art] Recently, various wireless transmission control systems have been developed in which a wireless transmitter transmits a wireless signal such as a weak radio wave, and a wireless receiver side receives the wireless signal and performs necessary control. is being developed.

An example of such a system is a wireless service call used in a restaurant.As shown in FIG. 6, each table is equipped with a wireless transmitter 100... The waiting area is equipped with a wireless receiver 200 having a plurality of display windows 200a, and when a customer operates a wireless transmitter operation switch (not shown) when necessary, the transmitter-specific information is displayed. A radio signal with a TD code is sent out, and this radio signal is received by the wireless receiver 200 to display the table number from which the call was made on the display section 200a, allowing prompt service. It is a system that can.

However, in such a system, since the radio signals output from each wireless transmitter 100 are configured using carrier waves of the same frequency, the radio signals transmitted from the plurality of wireless transmitters 100... When the transmission timings of the two signals overlap, the radio signals interfere with each other on the receiver 200 side, making it impossible to perform normal reception processing.

In order to avoid such inconvenience, Fig. 6(a) to (c)
As shown in , each wireless transmitter (A, B, C
)100 operation switches once, transmitter 10
A predetermined unique period TI, T2 . T3...
There is also a transmitter that prevents interference on the receiver 200 side by repeatedly transmitting a radio wave signal with the same transmission data multiple times, but in such a system, the number of transmitters 100 increases. Improvements have been desired as settings such as the transmission cycle and number of transmissions become more complex.

[Solution to be Solved by the Invention'': It is an object of the present invention to provide a wireless transmitter that can completely prevent interference on the receiver side by starting transmission.

Moreover, the present invention proposed at the same time aims to provide a wireless transmission control system using this wireless transmitter.

[Means for Solving the Problems] The present invention according to claim 1 proposed to achieve the above object monitors and receives a transmission band before transmitting a wireless signal when a transmission switch is operated. do,
A monitor receiver that determines whether or not there is a wireless signal transmitted from another transmitter, and when this monitor receiver does not receive a wireless signal from another transmitter, it immediately transmits a wireless signal, while receiving a wireless signal from another transmitter. and a signal processing unit that waits for transmission of the wireless signal until the wireless signal is stopped.

Further, the present invention according to claim 2 includes a plurality of wireless transmitters according to claim 1, and a wireless receiver that receives wireless signals transmitted from these transmitters and performs necessary control. It is configured.

[Function] In the present invention as set forth in claim 1, when the transmission switch is operated, a control signal is transmitted from the signal processing section to the monitor receiving section, and the wire toss signal is monitored and received. When it is determined that a wireless signal is not being transmitted from another device, a transmission permission signal is sent back to the signal processing unit, and the signal processing unit stops reception of the monitor reception unit and then sends the transmission data to the wireless transmission unit. transmit and send out wireless signals. However, when the monitor receiving section determines that a wireless signal is being transmitted from another wireless transmitter, it returns a transmission standby signal to the signal processing section, and the signal processing section returns the transmission standby signal returned from the monitor receiving section. In the present invention according to claim 2, wherein the wireless signal is similarly characterized by replying a transmission permission signal after waiting until the signal stops, while the wireless signal is being transmitted from one wireless transmitter, the wireless signal is not transmitted from another wireless transmitter. Even if you operate the device, it will go into a transmission standby state, so the wireless receiver side will reliably receive wireless signals without interference.

[Example] The present invention will be described in detail below with reference to the drawings. still,
In the following description, a configuration will be described in which a radio signal is used as the wireless signal.

FIG. 1 shows an example of the internal configuration of a wireless transmitter 1 of the present invention. In the figure, 1o is a transmission switch 10.
11 is a monitor receiving section that monitors the radio signal received by the receiving antenna RA; 12 is a wireless transmitting section that sends out the radio signal from the transmitting antenna TA.

The signal processing section 10 transmits a control signal to the monitor receiving section 11 to start monitor reception by operating the transmission switch 10a, and immediately starts transmitting the wireless signal in response to the determination signal returned from the monitor receiving section 11. Start or wait for wireless signal transmission.

The monitor receiving section 11 receives the control signal transmitted from the signal processing section 10, monitors and receives a radio wave signal in the same frequency band as the radio wave signal transmitted from the wireless transmitting section 12 via the receiving antenna RA, and When it is determined that a radio signal is being transmitted from one transmitter, a transmission standby signal is sent back to the signal processing unit 10, but when it is determined that no radio signal is being transmitted from another transmitter, a transmission permission signal is sent. Perform the action of replying.

Furthermore, the wireless transmitting unit 12 receives the transmission data transmitted from the signal processing unit 10, generates a wireless signal by modulating the carrier wave, and transmits it from the transmitting antenna TA.

The operation of the wireless transmitter 1 having such a configuration will be explained by referring to the time chart I in FIG.

1. Operation when no radio signal is transmitted from other transmitters.

(2) When the transmission switch 10a is operated, a control signal is transmitted from the signal processing section 10 to the monitor receiving section 11.

■The monitor receiving unit 11 receives a radio signal via the receiving antenna RA, and when it determines that a radio signal in the same frequency band as the radio signal to be transmitted is not being transmitted, it issues a transmission permission to the signal processing unit 10. send back a signal.

(2) Immediately upon receiving the transmission permission signal, the signal processing section 10 transmits the transmission data to the wireless transmission section 12 and sends out a radio wave signal via the transmission antenna TA.

2. Operation when radio signals are being transmitted from other transmitters.

(2) When the transmission switch 10a is operated, a control signal is transmitted from the signal processing section 10 to the monitor receiving section 11.

■The monitor receiving unit 11 receives the radio wave signal via the receiving antenna RA, and during the period when it determines that the radio wave signal is being transmitted in the same frequency band as the radio signal to be transmitted, the signal processing is performed. A transmission standby signal is continuously sent back to the unit 10, and a transmission permission signal is sent back when it is determined that the transmission of radio wave signals has stopped.

■The signal processing unit 10 waits for a transmission operation during the period when the transmission standby signal is returned from the monitor reception unit 11.
When the transmission permission signal is input, the transmission data is transmitted to the wireless transmission section 12, and a radio wave signal is transmitted from the transmission antenna TA.

In this way, in the wireless transmitter 1 of the present invention, before transmitting a radio signal, it is always checked whether the radio signal is being transmitted from another transmitter, so radio signals are not transmitted at the same time, and the reception This makes it possible to completely prevent side interference.

In particular, in the case of a wireless transmitter that takes some time to transmit a series of radio signals, there is a very high probability that the wireless transmitter will compete with radio signals transmitted from other wireless transmitters. By using a receiver, it is possible to completely prevent such competition between radio wave signals.

FIG. 3 shows an example of a wireless transmission control system configured using the wireless transmitter 1 described above, and is based on the operation time chart of the wireless transmitter shown in FIGS. As can be seen, when a wireless signal is being transmitted from one of the transmitters 1, transmission is put on standby even if the transmit switch of the other transmitter 1 is operated, so the time shown in Fig. 4 (g) As shown in the chart, interference is completely prevented on the receiver 2 side.

In the above explanation, the case where radio signals are used as wireless signals is given as an example, but interference can be prevented in the same way even when optical signals, ultrasonic signals, etc. are used in addition to radio signals. Possible 9 [Effects of the Invention] According to the present invention, before transmitting a wireless signal, the transmission band is monitored and received, and when the wireless signal is being transmitted, the transmission is put on standby, so that there is no possibility that the wireless signals will compete. Therefore, it is possible to provide a wireless transmitter that can effectively prevent interference.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the wireless transmitter of the present invention;
Figure 2 is a time chart explaining its operation, Figure 3 is a side view of the configuration of a wireless transmission control system using the wireless transmitter, and Figure 4 is a wireless signal transmitted from the wireless transmitter and its reception. A time chart explaining the wireless signals received on the machine side. Figure 5 is a schematic configuration diagram of a conventional wireless service call system. Figure 6 is a schematic diagram of a conventional wireless service call system.
The figure is a time chart explaining the operation of the wireless transmitter used in the system. [Description of symbols...Wireless transmitter 0...Signal processing section Oa...Transmission switch...Monitor reception section...Wire toss receiver

Claims (2)

[Claims] (1) In a wireless transmitter that transmits a wireless signal containing necessary transmission data in response to the operation of a transmission switch, when the transmission switch is operated, the transmission band is monitored and received before transmitting the wireless signal. a monitor receiver that determines whether or not there is a wireless signal transmitted from another transmitter; and a monitor receiver that immediately transmits a wireless signal when the monitor receiver does not receive a wireless signal from another transmitter; When the signal is received,
What is claimed is: 1. A wireless transmitter having an interference prevention function, comprising: a signal processing unit that waits to transmit a wireless signal until the wireless signal stops. (2) A wireless device comprising a plurality of wireless transmitters according to claim 1 and a wireless receiver that receives wireless signals transmitted from these transmitters and performs necessary control. Transmission control system.