JPS5851454B2 - mobile communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mobile communication device that transmits information to a moving object moving on a road, and has a function of controlling whether or not to output information depending on the moving direction of the moving object. .

Generally, radio waves are used as a medium for mobile communication, but in order to provide information to moving objects over a fixed section of the road, there are many methods that are put into practical use, such as installing lines along the road and using induced magnetic fields or leakage electric fields. .

However, if there are a mixture of moving objects in both directions within the communication range, and the information is intended only for objects going in one direction, the transmitting side sends a signal that can be identified by direction along with the information. A method is used to determine this on the receiving side.

That is, by operating a switch on the receiving side, the selection of signals indicating the direction is changed, and information corresponding to the current direction is output.

The most commonly used method for transmitting information that can distinguish between directions is to distinguish the frequencies of the radio waves used for uplink and downlink, and when uplink and downlink information is provided in different sections, they are transmitted as the same carrier wave. A method is also used in which the modulated codes and signals are different for uplink and downlink.

However, this method requires manpower to operate the switch, and if the moving object is a car traveling on a general road where it is unclear whether it is going up or down, the switching method requires the passenger to judge the direction. could not be expected to be fully implemented.

This invention was made in order to eliminate the above-mentioned drawbacks, and even if the occupants of a moving body do not recognize their own direction, the information transmission side automatically and reliably transmits information only to objects traveling in the direction designated by the information transmitting side. The purpose is to provide a mobile communication device for transmitting information.

Embodiments of the present invention will be described below with reference to the drawings.

This device is capable of distinguishing signals (radio waves or modulated signals) emitted by terrestrial transmitting equipment between the upstream and downstream sides of the target communication area. When it is confirmed that the information is correct, automatic control is performed so that the information is completely output.

An embodiment of the invention is shown in FIG. 1 and will be described.

In FIG. 1, a transmitting device 2 is installed on the roadside of a road 1,
The upstream antenna 3 divides the communication area into two and handles its transmission output.
is branched to the downstream antenna 4, and transmits the same transmission content, such as audio information (hereinafter referred to as information signal), but the antenna 3
A tone signal for identification (hereinafter referred to as "tone") indicating that the antenna is on the upstream side, and a tone indicating that the antenna is on the downstream side are superimposed on the information signal and modulated in parallel to generate high-frequency output power. There is.

Since the moving object 5 is traveling from upstream to downstream in the figure, the receiver determines that the order of the tones detected is correct,
The information signal is output, but since the order of tones in the moving body 6 in the opposite direction is reversed, this is determined and control is performed to close the gate during the transmission of the information signal.

This device will be explained in detail below.

FIG. 2 is a block diagram showing an overview of the transmitting device.

In FIG. 2, 11 and 12 are upstream and downstream transmitters, respectively, which have the same carrier frequency and have means for modulating an information signal and a tone in parallel as modulation inputs.

13 and 14 are respective transmission output terminals, which are connected via feeder lines to separate antenna systems having communication ranges in opposite directions.

When targeting cars running on the road, as an antenna,
It is appropriate to use a cable with the required length.

15 and 16 are upstream and downstream tone oscillators having different specific frequencies, the outputs of which are applied as modulation inputs to transmitters 11 and 12, respectively.

Reference numeral 17 denotes an information signal sending circuit, the output of which can be applied as a modulation input to the transmitting sections 11 and 12 together with the tone.

That is, the outputs of the transmission output terminals 13 and 14 are the same signal unless modulated by tone, but the tones for identification that are modulated in parallel with the information signal are different.

Therefore, the demodulated tones of the radio waves that are received first are different for cars going up and down.

If the in-vehicle receiver detects a tone indicating upstream (the side where a car approaching in the specified direction), it outputs a sound, but
If the system detects a tone indicating the direction downstream (the side where cars are approaching in the opposite direction), the information signal is blocked by a gate along the way and controlled so that it cannot be heard.

A block diagram showing an overview of the receiving device on the mobile body side is shown in FIG. 3 and will be described.

In FIG. 3, an input signal input from a reception input terminal 21 passes through a reception section 22 and a demodulation section 23, and an information signal is sent to a reception output section 25, but a gate 24 is inserted in the middle.

On the other hand, the demodulated output, which includes tones modulated in parallel with the information signal, is transmitted to the upstream tone detector 26 and the downstream tone detector 2.
7 allows its output to be used for control.

That is, 28 is a gate control device, 29 is a sequence determining circuit, and 30 is a timer, through which the following control operation is performed.

(1) When an upstream tone output is obtained in the standby state (no tone output and gate open), the gate is opened and the information signal is passed.

Even after the upstream tone disappears, a certain period of time is maintained by the timer.

When the downstream tone output is obtained during the period when the gate is open, it is held as it is, and after the downstream tone disappears and a certain period of time set by the timer has elapsed, the device returns to the initial standby state.

(2) When the downstream tone output is obtained in the standby state, the gate remains closed and the information signal is blocked.

When the upstream tone output is obtained following the downstream tone output or within a certain period of time determined by the timer after extinction, the information signal remains blocked; Return to standby state.

(3) Even if tone output is cut off due to interference or noise during reception, the timer maintains the current state for a certain period of time.

In the above description, it is preferable that the timer maintains the current state for a certain period of time, starts when the detector output is cut off, and that the holding time can be adjusted.

Furthermore, it is clear that instead of a timer, it can be replaced directly with something that can detect a fixed distance traveled after activation.

In this case, it may be possible to control the timing of closing the intermittent gate only by the rangefinder, without depending on the disappearance of the tone output.

Here, as an example of the present invention, wireless communication using radio waves emitted from a cable as a medium has been explained, but it goes without saying that it can be widely applied to the same purpose in transmission using other media used in a similar manner. be.

In addition, the target area is not limited to general roads, but can also be used for railways, waterways, specific passages, etc.

Transmission information is not limited to audio, but also applies to visual output.

It is clear that the signal for identifying a direction is not limited to a tone signal modulated in parallel with an audio signal, but also includes a digital signal or a control signal inserted at a specific position such as before or after a message. be.

As described above, it has a wide range of applications, but in recent years information systems for moving objects on general roads have been put into practical use. It is a relatively easy method of transmission, and being able to eliminate unnecessary information as much as possible is extremely effective in increasing the recipient's sense of trust.

As explained above, according to the mobile communication device of the present invention,
Information can be automatically selectively transmitted to a moving object moving in a specific direction.

[Brief explanation of the drawing]

1 is a system block diagram showing the entire mobile communication device according to an embodiment of the present invention, FIG. 2 is a block diagram of the transmitting device shown in FIG. 1, and FIG. 3 is a system block diagram showing the entire mobile communication device shown in FIG. FIG. 2 is a block diagram of a receiving device provided. In the figure, 1 is a road, 2 is a transmitter, 3 and 4 are first and second antennas, 5 and 6 are moving objects, 11° and 12 are first and second transmitters, and 15 and 16 are A tone oscillator that generates the first and second signals, 17 an information signal sending circuit, 23 a demodulation section that demodulates the received signal, 24 a gate, 25 a reception output section, 26° and 27 a tone detector, 28 A gate control device, 29 is an order determining circuit, and 30 is a timer. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A first device provided along a path of a moving object and defining a communication area.
and a second antenna, a first antenna modulated on this first antenna.
a transmitting device that feeds a modulated second signal to the second antenna and transmits an information signal, and a transmitting device that is installed in the mobile body and transmits the first and second signals from the transmitting device. When the first signal is received in the standby state, the information signal from the transmitter is passed through, and when the second signal is first received in the standby state, the information signal is passed from the transmitter. A mobile communication device comprising a receiving device that blocks information signals from the antenna and returns to a standby state after the mobile object passes through the communication range of the first and second antennas. 2. The first and second transmitting devices each have a modulating means.
A transmitting section, first and second signal generators connected to the first and second transmitting sections, and an information signal sending circuit connected to the first and second transmitting sections, respectively. A mobile communication device according to claim 1, characterized in that: 3. Mobile communication according to claim 1, characterized in that the identification signal modulating the first and second signals feeding the first and second antennas is a tone signal or a digital signal. Device.