JPS5842980B2 - Transmitting/receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmitting/receiving device having means for transmitting an effective interference signal to a wireless communication system.

FIG. 1 is a block wiring diagram showing an example of a conventional transmitting/receiving device of this type, in which 1 is a receiving antenna that receives a target radio signal, 2 is a receiving circuit that amplifies and detects the radio waves captured by this receiving antenna 1, and 3 4 is a transmitting antenna that emits the output of this transmitting circuit 3; 5 is a clock generating circuit that generates a clock signal; and 6 is a clock signal from this clock generating circuit 5 to generate the above-mentioned receiving circuit 2. This is a control circuit that controls the standby monitoring (look-through) time of the transmission circuit 3 and the transmission time of the transmission circuit 3.

In the transmitting/receiving device configured as described above, the transmission of interfering radio waves from the transmitting circuit 3 is stopped during the standby monitoring (look-through) period so that the receiving circuit 2 can perform the receiving operation reliably.

During the standby monitoring (look-through) period, the receiving circuit 2 detects the presence or absence of a target radio signal (a signal with a predetermined frequency), and sends a target radio signal to a signal exceeding a predetermined threshold level.
An output of "Yes" is sent to the control circuit 6.

When the control circuit 6 receives the "present" signal, it sends a transmission start signal to the transmission circuit 3 at a fixed timing.

After transmitting for a certain period of time, the transmitter stops transmitting in response to a signal from the control circuit 6 and enters standby monitoring (look-through) operation.

As described above, the standby monitoring (look-through) operation and the transmission operation are performed alternately and operated in a time-division manner.

FIG. 2 is an operational button diagram of the transmitting/receiving device, and in the figure, tsl, ts2. ts3 is the transmission period, tll, t12
is the standby monitoring (look-through) period.

These periods were usually not changed under certain conditions.

That is, in the figure, ts1 = tS2 - tS3 and t11
= t12.

As described above, the standby monitoring (look-through) operation and the transmitting operation are performed in a time-division manner, so the receiving antenna 1 and the transmitting antenna 4 may be used in common.

When shared, use one antenna by switching it with a switch or the like.

Note that the characteristics of the signal output from the transmitting circuit 3 may be unmodulated, or may be operated with an appropriate modulated signal or appropriate modulation format, and the optimal method is selected each time depending on the purpose. .

The above-mentioned transmitting/receiving devices use standby monitoring (look-through).
The period and repetition period can be easily measured, and after being measured, information may be efficiently transmitted within the time of this standby monitoring (look-through).To prevent this, standby monitoring ( It was necessary to frequently change the look-through time and repetition period, which required extremely complicated operation.

This invention was made in order to eliminate the above-mentioned drawbacks, and provides a transmitting/receiving device that can effectively jam radio waves by making the standby monitoring (look-through) time difficult to predict. The purpose is to obtain.

FIG. 3 is a block diagram showing one embodiment of the present invention, and numerals 1 to 6 are exactly the same as the conventional device described above.

7 is a random signal generating circuit that generates an irregular standby monitoring (look-through) cycle.

The operation of the transmitting/receiving apparatus configured as described above will be explained with reference to FIG.

FIG. 4 is an operational button diagram of the transmitting/receiving device shown in FIG. 3.

The control device 6 makes the generation time of standby monitoring (look-through) irregular based on the signal from the random signal generation circuit 1,
Therefore, the transmission periods are different, such as ts4\ts5\ts6.

Also, the standby monitoring (look-through) period t73yts+ is set to the shortest period necessary to detect the received signal.
In many cases, t13=t14, and the purpose of this device is to set it to a limit at which the time cannot be shortened any further.

The random signal generation circuit 7 performs standby monitoring (look-through)
The device generates a signal whose timing period is so irregular that it cannot be easily detected and measured by the other party, and may be a pseudo-random signal generation circuit, a random number generation circuit, or the like.

As mentioned above, the length of the standby monitoring (look-through) period is normally constant, but since the detection probability varies depending on the type of received signal to be detected, it is also variable. There are cases where it is useful.

As described above, the present invention has the advantage that effective interference can be performed by randomly changing the generation cycle of standby monitoring using a simple structure in which a random signal generating circuit is provided.

[Brief explanation of the drawing]

Figure 1 is a block wiring diagram showing an example of a conventional transmitter/receiver, Figure 2 is an operation pattern diagram of the transmitter/receiver in Figure 1, and Figure 3 is a block diagram showing an example of a conventional transmitter/receiver.
The figure is a block diagram showing one embodiment of the present invention, and FIG. 4 is an operation pattern diagram of the transmitting/receiving device shown in FIG. 3. In the figure, 2 is a receiving circuit, 3 is a transmitting circuit, 5 is a clock generating circuit, 6 is a control circuit, and γ is a random signal generating circuit. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a transmitting/receiving device that alternately repeats a standby monitoring operation in which a target radio signal is received during standby and a transmission operation in which jamming radio waves are transmitted after the standby monitoring operation is completed, the start timing of the standby monitoring operation is set randomly or A transmitting/receiving device comprising a random signal generating circuit that performs pseudo-random control.