JPH0661905A - Train radio system - Google Patents

Abstract

PURPOSE:To evade an unreceivable state of an on-vehicle station even at the boundary part of a base station zone by transmitting a transmission control signal through a central equipment on its adjacent base station surface so as to secure the complementary transmitting actions between the center equipment and its adjacent base station and by making each base station turn on and off its transmitting action based on the transmission of the transmission control signal. CONSTITUTION:A central equipment 21 outputs the different transmission signals to the base stations 22a-22n via a transmission signal wire circuit 3 and also outputs a transmission control signal via a transmission control signal wire circuit 23 to turn on and off the transmitting actions of the stations 22a-22n. At the same time, the equipment 21 secures the synchronization between the outputs of the transmission signal and the transmission control signal and a fixed period T in order to output alternately these control signals between the base stations adjacent to each other. Under such conditions, no radio wave interference section is produced for the receiving field of the radio wave received by an on-vehicle station 4 from a radio wave transmission/reception part 5 via the stations 22a-22n. This is due to a fact that the field intensity is alternately increased between the adjacent base stations in the period T as shown by the receiving fields t1 and t2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a train radio system in which an on-board station traveling on a track communicates with a base station via a radio wave transmitting / receiving section arranged along the track.

[0002]

2. Description of the Related Art FIG. 9 is an explanatory view showing a conventional train radio system, in which FIG. 9A shows its configuration and FIG. 9B shows a received electric field of an on-board station. In the figure, 1 is a central unit of the train radio system, 2 is a plurality of base stations installed at predetermined intervals along a train track, and 3 is a signal transmitted from the central unit 1 to each of these base stations 2. Is a wired line for transmitting a transmission signal. Reference numeral 4 denotes an on-board station that travels on a track mounted on a train, and 5 radiates radio waves to the on-board station 1 and receives radio waves radiated by the on-board station 1. For example, wireless relay devices are connected in cascade. 6 is a base station zone to which radio waves from each base station 2 reach. Reference numeral 7 denotes a radio wave interference section in which radio waves from both base stations 2 adjacent to each other near the boundary of the base station zone 6 interfere with each other.

FIG. 10 is a block diagram showing an example of the radio wave transmission / reception unit 5. In the figure, 2 and 4 are the base station and the on-board station shown in FIG. 9, and 8 is arranged along the track of the train. A plurality (several tens) of LCXs 9 that radiate radio waves to the on-board station 4 and receive the radio waves radiated by the on-board station 4 are connected in cascade to connect the signals to the on-board station 4 and A wireless relay device that amplifies a signal from the on-board station 4. Further, FIG. 11 is a block diagram showing an example of the wireless relay device 9.
1 is a semi-fixed attenuator connected to terminal A, 12, 15, 1
8 is a filter for blocking the passage of signals from the terminal A to the terminal B, 13 and 17 are filters for blocking passage of signals from the terminal B to the terminal A, and 14 is inserted between the filters 12 and 15. The semi-fixed attenuator 16 is an amplifier for amplifying the signal from the terminal A to the terminal B and the signal from the terminal B to the terminal A.

Next, the operation will be described. The central unit 1 outputs a different signal for each base station 2 via the transmission signal wire line 3, and each base station 2 modulates the signal received from the central unit 1 into a radio signal and sends it to the radio wave transmitting / receiving unit 5. To do. The radio wave transmitter / receiver 5 radiates the signal from the LCX 8 as a radio wave,
While the radio relay device 9 compensates for the loss due to the radio wave emission, the LCXs 8 are transmitted one after another and the radio wave due to the signal is emitted into the base station zone 6. That is, the signal input from the terminal A to the wireless relay device 9 is sent to the amplifier 16 via the semi-fixed attenuator 11 and the filter 13, is amplified, and passes through the filter 17 to the adjacent LCX 8 from the terminal B. Sent.
At this time, in the vicinity of the boundary of each base station zone 6, the radio waves emitted from the radio wave transmitting / receiving sections 5 on both sides overlap and interfere with each other, resulting in a radio wave interference section 7 as shown in FIG. 9B. The output level of the amplifier 16 is LCX.
The radio waves radiated into the space from 8 are at a sufficient level to reach the on-board station 4 moving in the corresponding relay section in the base station zone 6.

On the other hand, the on-board station 4 mounted on the train moving along the track in which the radio wave transmitting / receiving unit 5 is arranged along the railroad line is the closest LC to the radio wave transmitting / receiving unit 5 in the passing base station zone 6.
The central unit 1 receives the signal transmitted to the base station 2 by receiving the radio wave radiated from X8, and the central unit 1
The signal returned to is modulated into a radio signal and emitted as a radio wave into space. This radio wave is received by the nearest LCX8, is input to the wireless relay device 9 from the terminal B, and is transmitted to the base station 2 while compensating for the loss due to the LCX8. That is, in the wireless relay device 9, the signal input from the terminal A is filtered by the filter 1
The signal is sent to the amplifier 16 via 8 and the amplified signal is output from the terminal A to the adjacent LCX 8 via the filter 15, the semi-fixed attenuator 14, the filter 12 and the semi-fixed attenuator 11.

[0006] Documents describing the technology related to the conventional train radio system include, for example, Japanese Patent Laid-Open No. 51-
54306, JP-A-56-1635, JP-A-57-76942, and JP-A-57-76943.

[0007]

Since the conventional train radio system is constructed as described above, the base station zone 6
In the radio wave interference section 7 near the boundary of, the signal received by the on-board station 4 cannot be discriminated due to the so-called overreach phenomenon, and the signal cannot be received, and the output level of each wireless relay device 9 is always constant. Even for an LCX8 that does not have an on-board station 4 running inside and only needs to relay a signal to an adjacent wireless relay device 9, a level sufficient for the radio waves emitted from the LCX8 to reach the on-board station 4. Since the signal is amplified up to this point, there is a problem that power is wasted.

The inventions set forth in claims 1 and 2 have been made in order to solve the above-mentioned problems, and it becomes impossible for the on-board station to receive a signal even at the boundary of the base station zone. The aim is to obtain a train radio system that does not exist.

The invention according to claims 3 to 5 is
It is an object of the present invention to reduce unnecessary power consumption in a wireless relay device and obtain a train wireless system with low power consumption.

[0010]

A train radio system according to a first aspect of the present invention has a central function of transmitting a transmission control signal for controlling complementary transmission operations between adjacent base stations. The base station has the function of turning on / off the transmission operation according to the transmission control signal of the device.

In the train radio system according to the invention of claim 2, the base station has a function of controlling the magnitude of the transmission power according to the transmission control signal from the central unit.

Further, in the train radio system according to the present invention, the amplifier of the radio relay device in which the LCXs are connected in cascade is the first amplifier for amplifying the signal from the on-board station to the base station. And a second amplifier that amplifies the signal from the base station to the on-board station, the amplification degree of the second amplifier is made variable, and the on-board vehicle according to the output power control signal based on the position information of the on-board station. Only the output level of the second amplifier of the wireless relay device in the relay section in which the station is present is made high.

In the train radio system according to a fourth aspect of the present invention, the radio in the relay section before and after the relay section in which the on-board station is present according to the output power control signal based on the position information of the on-board station. The output level of the second amplifier of the repeater is also high.

According to the fifth aspect of the present invention, there is provided a train radio system according to an output power control signal based on position information of an on-board station and traveling direction information of the on-board station and its relay section. Second wireless relay device in the front relay section
The output level of the amplifier is high.

[0015]

According to the transmission control signal sent from the central unit, each base station according to the invention described in claim 1 controls ON / OFF of the transmission operation between adjacent base stations so as to be complementary to each other. By doing so, it is possible to prevent the occurrence of a radio wave interference section due to overreach, and realize a train radio system in which the on-board station does not become unable to receive a signal even at the boundary of the base station zone.

Further, each base station in the invention described in claim 2 is controlled according to a transmission control signal sent from the central unit so that the transmission outputs of adjacent base stations are complementary to each other. Realizes a train radio system that shifts the transmission signal in the radio interference section due to overreach to the side of the base station that is not transmitting, so that the on-board station does not become unable to receive the signal even at the border of the base station zone. To do.

Further, in the wireless relay device according to the present invention as defined in claim 3, only the wireless relay device in the relay section in which the amplifier is provided in correspondence with the signal direction and in which the on-board station exists, from the base station to the on-board station. By increasing the output level of the second amplifier for amplifying the signal to the output power control signal based on the position information of the on-board station to a high output, unnecessary power consumption in the wireless relay device is reduced and consumed. Realizes a train wireless system with low power consumption.

Further, in the train radio system according to the invention described in claim 4, the output level of the second amplifier of the radio relay device is set to a high output even in the relay section before and after the relay section in which the on-board station exists. By doing so, the signal is not interrupted when the on-board station moves over the relay section.

Further, in the train radio system according to the invention of claim 5, the output level of the second amplifier of the radio relay device in the relay section where the on-board station is present and the relay section in front of it is set to a high output. By doing so, it is possible to reduce power consumption while preventing interruption of signals when the on-board station moves beyond the relay section.

[0020]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment of the invention described in claim 1, and FIG.
The received electric field of the on-board station is shown in. In the figure, 3 is a transmission signal wire line, 4 is an on-board station, 5 is a radio wave transmission / reception section, and 6 is a base station zone, which are the same as those of the conventional ones given the same reference numerals in FIG. Is omitted. Further, 21 has a function of transmitting a transmission control signal for controlling the transmission operations to be complementary between the adjacent base stations, which is different from the one denoted by reference numeral 1 in FIG. The devices 22a to 22n are base stations different from those denoted by reference numeral 2 in FIG. 9 in that they have a function of turning on and off the transmission operation according to the transmission control signal from the central device 21. 23 is a central device 21 from each base station 22a ...
22n is a transmission control signal wired line for transmitting a transmission control signal sent to 22n.

Next, the operation will be described. Here, FIG.
3 is a time chart showing the signal output timing of the central device 21. The central unit 21 outputs to each of the base stations 22a to 22n a transmission signal different for each base station via the transmission signal wire line 3, and a transmission control signal wire line 23.
Each of the base stations 22a to 22n by outputting a transmission control signal via
ON / OFF control of the transmission operation of. At this time, the central unit 21 synchronizes the output of the transmission signal and the output of the transmission control signal with the constant period T as shown in FIG. 2, and between the adjacent base stations as shown in the example of the base stations 22a and 22b. Control to output them alternately. In this way, the electric field received by the on-board station 4 of the radio wave transmitted from the radio wave transmission / reception unit 5 via the base stations 22a to 22n is the reception electric field (t1) and the reception electric field (t2) shown in FIG. ), The electric field strength of the adjacent base stations alternately increases in the cycle T, so that no radio wave interference section occurs.

Example 2. In the first embodiment described above, the transmission operation of the adjacent base stations is alternately turned on / off, but the magnitudes of the transmission outputs of the adjacent base stations are alternately complemented. It may be controlled. FIG. 3 is an explanatory view showing an embodiment of such an invention described in claim 2, in which FIG. 3 (a) shows its configuration and FIG. 3 (b) shows the reception electric field of the on-board station. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In the figure, 2
4a to 24n are base stations different from those denoted by reference numerals 22a to 22n in FIG. 1 in that they have a function of controlling transmission power according to a transmission control signal from the central unit 21. In this case, as shown in FIG. 3 (b), the reception electric field of the on-board station 4 alternately increases for each adjacent base station zone 6, so that a signal is transmitted in the radio wave interference section at the base station zone boundary. The radio wave interference does not occur in the base station zone 6 in which the signal is being transmitted to the base station side where there is no signal.

Example 3. Further, in the above embodiment, the case where the transmission control signal wire line 23 between the central unit 1 and each of the base stations 22a to 22n has one line for each of the base stations 22a to 22n has been described. , Two transmission control signal wire lines 23a and 23b
May be configured to be commonly connected to every other base station, and the same effect as that of the above-described embodiment is obtained.

Example 4. Next, a fourth embodiment of the present invention will be described with reference to the drawings. 5 is a block diagram showing an embodiment of the invention described in claim 2, and FIG. 6 is a block diagram showing an example of the wireless relay device thereof. The same parts as those in FIGS. 10 and 11 are designated by the same reference numerals. And avoid duplication of explanation. In FIG. 5, 25a to 25d are signals from the terminal A to the terminal B,
That is, the signal from the base station 26 to the on-board station 4 and the signal from the terminal B to the terminal A, that is, the signal from the on-board station 4 to the base station 26 are respectively amplified by individual amplifiers, and the signals from the terminal A to 1 in that the output level of the amplifier for amplifying the signal to the terminal B is controllable according to the output power control signal.
The wireless relay device is different from the device having the reference numeral 9 attached to 0. Reference numeral 26 is a base station different from that indicated by reference numeral 2 in FIG. 10 in that it has a function of generating this output power control signal based on the position information of the on-board station 4, and 27 is its output. A power control signal is transmitted from the base station 26 to each wireless relay device 25.
It is a wired line for the output power control signal transmitted to a to 25d. Further, in FIG. 6, reference numeral 16a denotes a first amplifier for amplifying a signal from the terminal B to the terminal A at a low output level that only needs to be relayed to the adjacent wireless relay devices 25a to 25d, and 16b denotes a terminal A from the terminal A. Amplifies the signal to terminal B,
Output power control signal In accordance with the output power control signal from the wired line 27, the high power level at which the radio wave radiated into the space from the LCX8 reaches the on-board station 4 moving in the relay section, Is a second amplifier that can be switched to a low output level of.

Next, the operation will be described. Each of the wireless relay devices 25a to 25d controls the output level of the second amplifier 16b in response to the output power control signal sent from the base station 26 via the output power control signal wired line 27. In the example shown in FIG. 5, the on-board station 4 uses the wireless relay device 25.
Since the mobile station is moving in the relay section of the LCX8 of b, the base station 26 uses the second amplifier 1 of the wireless relay device 25b only.
An output power control signal for setting the output level of 6b to a high output level and the output level of the second amplifier 16b of the other wireless relay devices 25a, 25c, ... It is sent to the line 27. Therefore,
The output level of the second amplifier 16b is increased only to the wireless relay device 25b to a level at which the radio waves radiated into space from the LCX8 can sufficiently reach the on-board station 4 moving in the relay section, In the other wireless relay device, the output level of the second amplifier 16b is lowered to a level required to relay the received signal to the adjacent wireless relay device. As a result, in the wireless relay devices 25a to 25d in which the on-board station 4 is not passing through the relay section, the output level of the second amplifier 16b is also low and wasteful power consumption is suppressed.

Example 5. In the fourth embodiment described above, the case where the on-vehicle station sets the output level of the second amplifier to a high output only for the wireless relay device existing in the relay section has been described. Also in the relay device, the output level of the second amplifier may be set to a high output. FIG. 7 is a block diagram showing an embodiment of such an invention as set forth in claim 4, in which 28 is a relay section in which the on-board station 4 exists based on the position information of the on-board station 4. Wireless relay devices 25a to 25 in adjacent relay sections
Also for d, reference numeral 2 in FIG. 5 is that an output power control signal that makes the output level of the second amplifier high is generated.
It is a base station different from the one marked with 6. In this case, as shown in FIG. 7, if the on-board station 4 is within the relay section of the wireless relay device 25b, the second power is also output to the wireless relay devices 25a and 25c by the output power control signal from the base station 28.
The output level of the amplifier is also high. Therefore,
As shown by the broken line in FIG.
When moving to the relay section of a or 25c, even if there is some delay in the transition of the output level of the second amplifier in the wireless relay devices 25a to 25d from low output to high output, the base station 28 will be onboard. The signal to the station 4 is not interrupted.

Example 6. Further, in the fifth embodiment, the second amplifier of the wireless relay device is set to a high output level also in the relay section before and after the relay section in which the on-board station exists. Regarding the wireless relay devices in the relay sections adjacent to each other in the direction, the second amplifier may be left at the low output level. FIG. 8 is a block diagram showing an embodiment of such an invention described in claim 5,
In the figure, reference numeral 29 indicates, based on the position information of the on-board station 4 and its traveling direction information, the second of the wireless relay devices 25a to 25d in the relay sections adjacent to the traveling direction of the on-board station 4 as well.
The base station is different from the one with reference numeral 26 in FIG. 5 or the one with reference numeral 28 in FIG. 7 in that an output power control signal for making the output level of the amplifier of FIG. In this case, as shown in FIG. 8, if the on-board station 4 is within the relay section of the wireless relay device 25b, the wireless relay device 25a
In this case, the output level of the second amplifier is high, and the signal from the base station 29 to the on-board station 4 is interrupted when the on-board station 4 moves as shown by the broken line in FIG. In addition, since the second amplifier of the wireless relay device 25c has a low output level, wasteful power consumption can be suppressed as compared with the case of the fifth embodiment.

[0028]

As described above, according to the invention described in claim 1, according to the transmission control signal transmitted from the central unit, the ON / OFF of the transmission operation is mutually complemented between the adjacent base stations. Since it was configured to control so that
It is possible to prevent the occurrence of a radio wave interference section due to overreach, and it is possible to obtain a train radio system in which the on-board station does not become unable to receive a signal at the boundary of the base station zone.

According to the second aspect of the invention, according to the transmission control signal transmitted from the central unit, the transmission outputs of adjacent base stations are controlled so that their magnitudes are complementary to each other. With this configuration, the radio wave interference section due to overreach can be shifted to the base station side that is not outputting the transmission signal. There is an effect that a train radio system can be obtained in which the on-board station does not become unable to receive signals even at the boundary of the base station zone.

[0030] According to the invention as defined in claim 3, the wireless relay device can amplify the signal from the on-board station to the base station.
Second amplifier for amplifying the signal from the base station to the on-board station
So that the output level of the second amplifier of only the wireless relay device in the relay section in which the on-board station is present is set to a high output by the output power control signal based on the position information of the on-board station. Since it is configured, it is possible to reduce unnecessary power consumption in the wireless relay device, and to obtain a train wireless system with low power consumption.

According to the invention described in claim 4, the output level of the second amplifier is set to a high output also in the wireless relay device in the relay section before and after the relay section in which the on-board station is present. With this configuration, there is an effect that a train radio system in which signals are not interrupted when the on-board station moves over the relay section can be obtained.

According to the fifth aspect of the invention, the output level of the second amplifier of the wireless relay device in the relay section in which the on-board station is present and the relay section in front of it is set to a high output. Since it is configured as described above, there is an effect that a train radio system capable of reducing power consumption can be obtained while preventing interruption of signals when the on-board station moves beyond the relay section.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is a time chart showing the timing of signals transmitted by the central unit in the above-mentioned embodiment.

FIG. 3 is an explanatory diagram showing Embodiment 2 of the present invention.

FIG. 4 is an explanatory diagram showing Embodiment 3 of the present invention.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a wireless relay device in the above embodiment.

FIG. 7 is a block diagram showing a fifth embodiment of the present invention.

FIG. 8 is a block diagram showing a sixth embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a conventional train radio system.

FIG. 10 is a block diagram showing the radio wave transmitting / receiving unit.

FIG. 11 is a block diagram showing the wireless relay device.

[Explanation of symbols]

 4 On-board station 5 Radio wave transmitting / receiving unit 8 LCX 16a First amplifier 16b Second amplifier 21 Central apparatus 22a-22n Base station 24a-24n Base station 25a-25d Wireless relay apparatus 26 Base station 28 Base station 29 Base station

Claims (5)

[Claims] 1. A plurality of base stations, each of which is connected to a central device, are installed along a track along which an on-board station moves, and each of the base stations is arranged along the track to provide the on-board station. In a train radio system that radiates radio waves to and transmits radio waves from the on-board station, in a train radio system, the central device is controlled so that its transmission operation is complementary between adjacent base stations. A function of transmitting a transmission control signal to each of the base stations, and turning on the transmission operation of each of the base stations in accordance with the transmission control signal from the central device.
A train radio system characterized by having a function to turn it off. 2. A plurality of base stations, each of which is connected to a central unit, are installed along a track along which an on-board station moves, and each of the base stations is arranged along the track to provide the on-board station. In a train radio system that radiates radio waves to, and connects a radio wave transmission / reception unit that receives radio waves from the on-board station, so that the transmission operation between the adjacent base stations is complementary to the central device. A train radio having a function of transmitting a transmission / reception control signal to be controlled to each of the base stations, and having a function of controlling the transmission power of each of the base stations according to a transmission control signal from the central device. system. 3. A plurality of leaky coaxial cables that radiate radio waves to an on-board station and receive radio waves from the on-board station, are arranged along a track along which the on-board station moves, and each of the leaky coaxial cables. In a train radio system in which signals are transmitted and received via the leaky coaxial cable between the base station and the on-board station, which are connected in cascade by a radio relay device.
The wireless relay device includes a first amplifier that amplifies a signal from the on-board station to the base station, and a second amplifier that can control output power to amplify a signal from the on-board station to the on-board station. According to the output power control signal based on the position information of the on-board station, the output level of the second amplifier of the wireless relay device in the relay section in which the on-board station is present is set to high output, and A train radio system in which the output level of the second amplifier of the radio relay device is low. 4. A second amplifier of the wireless relay device in a relay section in which the on-board station exists and a relay section adjacent to the relay section in accordance with the output power control signal based on the position information of the on-board station. The train radio system according to claim 3, wherein the output level is set to a high output and the output level of the second amplifier of the other wireless relay device is set to a low output. 5. A relay section in which the on-board station is present, a relay section in which the on-board station is present, and a traveling direction of the on-board station according to an output power control signal based on position information of the on-board station and its traveling direction information. The output level of the second amplifier of the wireless relay device in the adjacent relay section is set to high output, and the output level of the second amplifier of the other wireless relay device is set to low output. Train radio system described.