JPH10285101A - Train radio system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an over-reach incoming call between base stations of other routes or other line sectors of the same route by avoiding a voice signal from returning to other command console through another base station. SOLUTION: A calling voice from a command console 1a to a train 5 is sent from a base station 43 to the train 5 and a tone signal is added to a head of a voice modulation signal to be sent in the case of the transmission. When the transmission signal over-reaches a base station 45, the base station 45 detects the tone signal from the received signal and disconnects a signal line 7 connecting to a command control 1b, then the received voice signal is not sent to the command console 1b through a central equipment 3 and a line exchange 2 thereby preventing an over-reach incoming call substantially.

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 for preventing overreach termination between base stations on other routes or other routes on the same route when the same channel is used on a plurality of routes and routes. .

[0002]

2. Description of the Related Art Conventional train radio systems for conventional lines are:
The same channel is used for a plurality of routes and sections, and the routes and sections are separated using a tone squelch method or the like to prevent interference. However, in a system in which routes and line divisions are not performed, overreach termination occurs between base stations on other routes or the same route and other line sections. The conventional train radio systems for conventional lines are roughly classified into two types: a system in which channels are assigned to each line, and a system using a nationwide common channel. Among them, in the former system, since the channel is different for each route or the channel is different for transmission and reception, there is no interference due to overreach termination between base stations on other routes or the same route and other routes.

On the other hand, in the case of the latter system, in a region where a plurality of lines are operating at one station, a base station of a train radio is often close to the station. When a call is transmitted from a command console, a radio wave may also arrive at a base station on another route in the vicinity, and the transmitted voice may be heard from another command console. For this reason, there was a problem that the instruction work was hindered, and howling occurred when the command desk was close to the terminal.

In order to prevent such a problem, when the above tone squelch method is adopted and a tone is allocated to each route, it is possible to prevent a call failure due to an overreach incoming call between other routes. However, in the case of a system that uses the same channel press talk system for both transmission and reception,
Overreach incoming calls cannot be prevented on the same line and other lines.

FIG. 8 is a block diagram showing a conventional example of a C-type train radio system which employs the press-talk system and does not employ the tone squelch system. 1a, 1
b, 1c are command consoles for issuing operation commands, 2 is a circuit switch for connecting the central device 3 to the command consoles 1a, 1b, 1c, and 3 is base stations 41, 42, 43 in the A section and base stations in the B section. Station 4
A central device 5 that controls communication with the train (mobile station) 5 while controlling the trains 4, 45, 46, and 5 is a train (mobile station) that performs wireless communication with the base stations 41 to 46. It is a base station that performs wireless communication with the train 5.

For example, when an operation command (solid line in the figure) from the command console 1a calls the train 5 located in the A section wirelessly via the base station 43 in the A section, the transmission radio wave is transmitted to the B line. There is a case where an overreach call arrives at the base station 44 in the district.
In such a case, the calling voice of the operation command is transmitted from the base station 44 to the command console 1b along the route shown by the broken line in the figure, and the calling voice is heard from the speaker of the command console 1b, and the call voice is transmitted between other routes. The same inconvenience as in the case of overreach incoming occurs.

Further, in the case of the tone squelch system, since a tone is continuously output during transmission, a radio device not compatible with the system can hear a tone in addition to a voice at the time of reception, which hinders communication. Therefore, if a tone is assigned as an identification signal for each line section in order to prevent an overreach call on the same line / other line section, interference due to an overreach call on the same line / other line section can be prevented. Both stations (on-vehicle stations) have the problem that significant remodeling is required.

[0008]

As described above, in the conventional train radio system, a train radio C type which uses a common wave on a plurality of routes, employs a press talk system, and does not employ a tone squelch system. Since the system cannot prevent overreach incoming calls between base stations on other routes or on the same route and other routes, the voice transmitting the operation command can be heard from another command desk through another base station. In the worst case, there was a problem of howling.

Accordingly, the present invention has been made to solve the above-mentioned problem, and it is intended to prevent voice from returning to another command desk through another base station and to make another route or the same route and another line section. It is an object of the present invention to provide a train radio system capable of preventing overreach incoming calls between base stations.

[0010]

According to a first aspect of the present invention, there are provided a plurality of base stations connected to a plurality of command consoles by wires to transmit and receive signals. In a train radio system for wirelessly transmitting and receiving signals, when wirelessly transmitting a signal from the base station to the train, tone signal adding means for adding a tone signal to be transmitted together with the signal to the beginning of the transmission signal; Discriminating means for discriminating whether or not a tone signal is added to the signal; and transmitting the received signal to the command console when the discriminating means discriminates that the tone signal is added to the received signal. The base station is provided with control means for performing control not to perform the control.

[0011] With this configuration, since the tone signal is added to the head of the signal transmitted from the base station by the tone signal adding means, when another base station receives this signal, the other base station receives the signal. When the discriminating means of the station discriminates the addition of the tone signal, it is possible to discriminate that the received signal is a signal transmitted not from a train but from an adjacent base station, and the control means of the other base station can Since the received signal is not transmitted to the command console, voice transmitted from one command console is not output from another command console.

The control means of the invention according to claim 2, wherein when the discriminating means determines that the tone signal is added to the head of the received signal, a signal line for transmitting a signal to the command console is connected to the base station. It has a configuration to disconnect from the station.

[0013] With this configuration, the received signal to which the tone signal is added at the beginning has no signal line for transmission to the command console, and is not transmitted to the command console.

According to a third aspect of the present invention, there are provided a plurality of base stations which are connected to a plurality of command consoles by wires to transmit and receive signals, and transmit and receive signals from any one of these base stations to a train by radio. In the system, and in a train radio system having a loopback test function of receiving leaked radio waves of a signal transmitted from a base station and transmitting the received signal to the control console, a signal is transmitted from the base station to the train. A tone signal adding means for adding a tone signal to be transmitted together with the signal at the head of the transmission signal during wireless transmission; a determining means for determining whether a tone signal is added to the received signal; When it is determined by the means that the tone signal is added to the received signal, control is performed so that the received signal is not transmitted to the command console, and the received signal during the loopback test is performed. If that the tone signal is added is determined by the determination means has the structure and control means for performing control to transmit the received signal to the command console side to the base station.

According to such a configuration, since the tone signal is added to the head of the signal transmitted from the base station by the tone signal adding means, when another base station receives this signal, the other base station receives the tone signal. When the discriminating means of the station discriminates the addition of the tone signal, it is possible to discriminate that the received signal is a signal transmitted not from a train but from an adjacent base station, and the control means of the other base station can Since the received signal is not transmitted to the command console, voice transmitted from one command console is not output from another command console. Also, at the time of the loopback test, the control means transmits the received signal to the command console even if the discriminating means determines that the tone signal is added to the received signal.

According to a fourth aspect of the present invention, when the determination section determines that the tone signal is added to the head of the received signal, the control section sets a signal line for transmitting a signal to the command console to the base station. Control is performed to disconnect from the base station, but if the received signal is a signal at the time of the loopback test, control is performed to keep the signal line connected to the base station.

With such a configuration, the received signal with the tone signal added to the head is not transmitted to the console, but during the loopback test, the received signal with the tone signal added to the head is also transmitted to the base station. The signal is transmitted to the command console through a signal line connected to the station.

According to a fifth aspect of the present invention, there is provided a tone signal adding means including a setting means for setting a length of a tone signal to be added to the head of the signal within a predetermined range.

With such a configuration, the length of the tone signal is adjusted by the setting means, and the connection between the tone signal and the transmission signal is adjusted. A signal having no overlap between the tone signal and the transmission signal can be transmitted.

According to a sixth aspect of the present invention, the tone signal is fa
Hz, and a signal to be transmitted with this tone signal added to the head is transmitted through a high-pass filter with a cutoff frequency faHz.

With such a configuration, a signal to which a tone signal is added at the beginning is fa by the high-pass filter.
Since the level of the signal component below Hz is low, the discriminating means does not erroneously determine that a signal other than the tone signal is a tone signal.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the train radio system of the present invention. 1a, 1
b, 1c are command consoles for issuing operation commands, 2 is a circuit switch for connecting the central device 3 to the command consoles 1a, 1b, 1c, and 3 is base stations 41, 42, 43 in the A section and base stations in the B section. Station 4
A central device for controlling communication with a train (mobile station) 5 while controlling the trains 4, 45 and 46, a train (mobile station) 5 for performing wireless communication with a base station, and 41 to 46 with the train 5 A base station that performs wireless communication, 6 is an antenna that transmits and receives radio waves to and from the train 5, and 7 is a signal line that connects the base stations 41 to 46 and the central unit 3.

FIG. 2 is a block diagram showing a detailed example of the base station 41 (the same applies to other base stations). 11 sends and receives signals to and from the signal line 7 connected to the central device 3,
Control to output the voice modulation signal and the press signal received from the signal line 7 to the encoder 12, and to input the incoming signal and the reception signal output from the decoder 14 and output the signal to the signal line 7 connected to the central unit 3 And 12 is an encoder that encodes an audio modulation signal or a press signal input from the control unit 11 and outputs the encoded signal to the wireless unit 16.
1 is a signal switching unit for switching between a voice modulation signal and a tone signal input from 1;
A decoder 15 decodes a reception output and an incoming signal input through the control unit 11 and outputs the signal to the control unit 11. A decoder 15 controls whether or not the signal received by the radio unit 16 is transmitted to the central unit 3 through the control unit 11. A receiving line control unit 16 for performing transmission and reception of signals with the train 5 is a wireless unit. In addition, the encoder 1
2. The signal switching unit 13, the decoder 14, and the receiving line control unit 15 constitute an overreach prevention device 50.

FIG. 3 is a circuit diagram showing a detailed example of the encoder 12 and the signal switching section 13 shown in FIG. The encoder 12 includes an amplifier 121 that amplifies the audio modulation signal input from the control unit 11, and 30 of the output signals of the amplifier 121.
High-pass filter 122 that passes 0 Hz or more, 300 Hz
Is provided. Further, the signal switching unit 13 includes the tone signal generator 12.
3, a switch 131 for turning on / off the tone signal output from the high-pass filter 122, a switch 132 for turning on / off the voice modulation signal input from the high-pass filter 122, and a timer 13 for time-controlling the on / off of the switches 131 and 132.
3, an inverter 134 for inverting the polarity of the control signal from the timer 133, and an amplifier 135 for amplifying the signal obtained from the switches 131 and 132 and outputting the amplified signal to the transmitting unit 161 of the wireless unit 16. The control unit 11 has a press signal detection unit 111 that detects a press signal from a signal sent from the central device 3 via the signal line 7.

FIG. 4 is a circuit diagram showing a detailed example of the decoder 14 and the receiving line control unit 15 shown in FIG. The decoder 14 includes an amplifier 141 that amplifies a reception output of the radio unit 16,
A low-pass filter (LPF) 142 that passes 300 Hz or less among the signals output from the amplifier 141, a tone signal detector 143 that detects a tone signal from a signal input from the low-pass filter 142, and a signal output from the amplifier 141. And a inverter 145 for inverting the polarity of the detection signal output from the tone signal detection unit 143.

The receiving line control unit 15 includes an inverter 151 for inverting the polarity of the press signal input from the radio unit 16, an inverter 152 for inverting the polarity of the incoming signal input from the radio unit 16, and an incoming call from the inverter 152. A delay circuit 15 for delaying a signal for a predetermined time and outputting the signal
4. An exclusive OR circuit 155 for taking an exclusive OR of the outputs of the inverter 151 and the delay circuit 154, and the AND circuit 15 is cleared by the output of the exclusive OR circuit 155.
Flip-flop circuit 1 clocked by the output of D7
56, an exclusive OR circuit 1 for taking an exclusive OR of outputs of the delay circuit 154 and the D flip-flop circuit 156
58, and an inverter 159 for inverting the output of the exclusive OR circuit 158. The control unit 11 is connected to the signal line 7
And a relay control unit 112 that opens and closes the contact 113.

Next, the operation of this embodiment will be described. The system shown in FIG. 1 is a train radio C type, which uses a nationwide common wave, but does not employ a tone squelch system in a press talk system. This figure shows a situation where the base station 43 in the A-line section is designated as a station from the command console 1a, and when transmitting to the train, the transmitted voice reaches the base station 44 in the B-line section. By the way, the base station 43 in the area A
When the station is designated, the other base stations 41, 42, etc. in the same line section are busy, and the communication lines other than the base station designated by the station are not connected. In the case of one line and one line section, the tone squelch method may be adopted for all lines. However, since it is generally composed of one line and a plurality of lines as shown in FIG.
3 may be received by the base station 44 in the adjacent B line section.

In such a case, the base station 44 cannot receive the signal because the voice cannot be distinguished from the one transmitted from the other base station 43 or the one transmitted from the train 5 as it is conventionally. Then, the reception line is connected to the central device 3, so that a so-called overreach incoming call is performed. Therefore, the signal transmitted from the base station 43 or the signal transmitted from the train 5 is identified by the base station 44 so that the reception line is not connected even if the signal transmitted from the base station 43 is received. This embodiment employs a configuration for substantially preventing overreach reception between base stations on the same route and other lines.

Next, the operation when the base station 43 transmits the voice transmitted from the command console 1a to the train 5 will be described with reference to FIGS.
This will be described with reference to FIG. When receiving the signal (voice modulation signal) transmitted from the command console 1a through the signal line 7, the control unit 11 outputs the received signal to the encoder 12 of the overreach prevention device 50. At the same time, when the press signal detecting section 111 of the control section 11 detects the press signal from the received signal, the press signal detecting section 111 transmits the detected press signal to the tone signal generator 1.
23 and the timer 133. Initially, switch 13
1 is on and switch 132 is off.

Here, the received signal received by the control unit 11 of the base station 43 is a low active press signal as shown in FIG. 5 (A) and a microphone of the command console 1a as shown in FIG. 5 (B). It consists of the picked up voice modulated signal. Therefore, when the control unit 11 receives the signal, first, the press signal detected by the press signal detection unit 111 is output to the tone signal generator 123 and the timer 133. Thus, the tone signal generator 123 is activated to generate a tone signal. At the same time, the timer 133 is activated and starts timing. The tone signal generated from the tone signal generator 123 passes through the switch 131 to the amplifier 1.
35 to the transmitting section 161 of the radio section 16. Therefore, transmitting section 161 transmits the input tone signal to antenna 6
To train 5.

Thereafter, the timer 133 times out, turning off the switch 131 and simultaneously turning off the switch 13.
Turn 2 on. Thereby, the tone signal generator 123
The input of the tone signal output from the amplifier 135 to the amplifier 135 is stopped, and the tone signal is transmitted from the transmission unit 161 for a short time as shown in FIG. At the same time as stopping the input of the tone signal to the amplifier 135,
Since a voice modulated signal as shown in FIG. 2B is input, the voice modulated signal is amplified and transmitted to the transmitting unit 16 of the radio unit 16.
1 is output. As a result, an audio modulation signal as shown in FIG. 5C is transmitted from the transmitting unit 161 to the train 5.

That is, the base station 43 transmits to the train 5 a voice modulated signal preceded by a tone signal. However, the transmission time of the tone signal is 500 msec to 1
It is assumed that the time measured by the timer 133 can be set so that the adjustment can be made up to the second. The input line of the modulation signal from the control unit 11 has a cutoff of 300H.
The reason why the high-pass filter 122 of z is inserted is that the voice signal transmitted from the base station is set to 300 Hz or more so that this voice signal is not erroneously detected as an identification signal of 300 Hz or less, This is to prevent the decoder from malfunctioning due to voice from another base station.

Next, the receiving operation of the base station 44 will be described with reference to FIG.
This will be described with reference to FIG. When the radio section 16 receives a signal from the base station 43, the press signal is at a high level and the incoming signal is at a low level as shown in FIG. Therefore, the output of the inverter 151 goes low, and the output of the inverter 152 goes high. As a result, the output of the delay circuit 154 also goes high, and the output of the exclusive OR circuit 155 goes high. As a result, the D flip-flop circuit 156 is in a state where it is not cleared. At this time, a high-level signal is input to the data terminal D of the D flip-flop circuit 156, and a high-level signal is input to one terminal of the AND circuit 157. Normally, since the output of the inverter 145 is at a low level, the output of the AND circuit 157 is at a low level.

By the way, after the above-mentioned incoming signal, a voice modulated signal having a tone signal at the head thereof is inputted from the radio section 16 to the high-pass filter 144 and the low-pass filter 142 through the amplifier 141. Low-pass filter 142
In order to pass a signal of 300 Hz or lower, only the first tone signal is passed and output to the tone signal detector 143. For this reason, the tone signal detection unit 143
As shown in (B), the tone signal is detected and its output is set to a low level. Therefore, both terminal inputs of the AND circuit 157 become high level, and the output thereof becomes high level only during the tone signal detection period.

Thus, the D flip-flop circuit 1
One pulse is input to the 56 clock terminals CLK, and the above-described high-level signal is latched from the data terminal D,
The terminal goes high. As a result, the exclusive OR circuit 158 sets its output to low level because both inputs are at high level. As a result, the output of the inverter 159 becomes high level, current does not flow to the relay control unit 112, and the contact 114 is turned off. For this reason,
The sound modulation signal output from the high-pass filter 144 does not return to the command console 1b on the upstream side of the signal line 7 because the contact 113 is turned off, and the voice due to overreach arrival is output from the command console 1b. Disappears.

However, when a call arrives at the base station 45 from the train 5, since the tone signal is not added to the head of the voice modulation signal, the tone signal detection unit 143 does not detect the tone signal, and the output is low level. Will remain. Therefore, the output of the inverter 145 remains at the high level, the AND circuit 157 remains at the low level, and does not output one pulse to the D flip-flop circuit 156. As a result, the D flip-flop circuit 156 does not latch the data, and the output of the Q terminal remains at the low level. Therefore, the exclusive OR circuit 158 is at the high level while the incoming signal shown in FIG. 7A is at the low level, the current is still supplied to the relay control unit 112, and the relay contact 113 is closed. It remains. Therefore, after that, the voice modulation signal input from the high-pass filter 144 is transmitted to the upstream side of the signal line 7, and the voice transmitted from the train 5 is output from the command console 1b on the upstream side.

Base station 41 for train radio C type system
46 has a loopback test mode. In this case, the transmitting unit and the receiving unit of the radio unit 16 of the base station are simultaneously started, and the transmission output of the own station is switched from the antenna 6 to the dummy. Thus, when the leaked radio wave of the own station is received, the transmission sound of the operation command is heard as the reception sound, so that it can be confirmed whether the base station is operating. If no countermeasures are taken, in the loopback mode, the tone of the own station is detected by the tone signal detector 14.
3, the relay contact 113 is opened, so that the transmission line of the own station is disconnected, and the loopback test cannot be performed.

Therefore, in this example, in the loopback mode, the press signal output from the radio unit 16 to the receiving line control unit 15 becomes low level, so that the output of the exclusive OR circuit 155 becomes low level. . As a result, the D flip-flop circuit 156 is cleared. Therefore, at this time, even if the tone signal detector 143 detects a tone,
The Q terminal of the flip-flop circuit 156 does not go high, and the relay contact 113 of the control unit 11 remains closed. At this time, the audio modulation signal output from the high-pass filter 144 is output from the control console upstream from the signal line 7. It is sent to one side, and a loopback test can be performed. The above configuration and operation are the same in other base stations.

According to the present embodiment, when a voice modulated signal from the command console is transmitted from the base station to the train 5, a tone signal is added to the head of the voice modulated signal. The receiving base station detects the tone signal, identifies that the signal is from the nearest base station, disconnects its own receiving line (signal line 7), and receives the received voice modulation signal. Since the signal is not returned to the command console side, it is possible to substantially prevent an overreach incoming call between base stations on the same line and other lines. In the loopback mode, the D flip-flop circuit 156 is cleared so that the receiving line is not disconnected by the tone of the own station, so that the loopback test for the base station can be performed without any trouble. Moreover, in this example, the above effect can be obtained only by inserting the overreach prevention device between the radio unit 16 of the base station and the control unit 11 thereof, thereby minimizing the modification of the communication system and reducing the modification period. It can be shortened and the remodeling cost can be reduced.

It should be noted that overreach termination between other routes without using the tone squelch method can be prevented by providing a base station between the other routes in the same configuration as described above, and the same effect can be obtained.

[0041]

As described above, according to the first aspect of the present invention, voice is prevented from returning to another command console through another base station, so that it can be transmitted between base stations on another route or on the same route and another line section. Overreach incoming calls can be prevented.

According to the second aspect of the present invention, it is possible to prevent an overreach incoming call between base stations on another route or another route section on the same route, and to perform a return test without any trouble.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a train radio system according to the present invention.

FIG. 2 is a block diagram showing a detailed example of the base station shown in FIG.

FIG. 3 is a circuit diagram showing a detailed example of an encoder and a signal switching unit shown in FIG. 1;

FIG. 4 is a circuit diagram showing a detailed example of a decoder and a receiving circuit control unit shown in FIG. 2;

FIG. 5 is a time chart showing a transmission operation of the base station shown in FIG. 1;

FIG. 6 is a time chart showing a receiving operation of the base station shown in FIG. 1;

FIG. 7 is a time chart showing a reception operation at the time of a loopback test of the base station shown in FIG. 1;

FIG. 8 is a block diagram showing a configuration example of a conventional train radio system.

[Explanation of symbols]

 1a to 1c Command console 2 Circuit exchange 3 Central unit 5 Train 6 Antenna 7 Signal line 11 Control unit 12 Encoder 13 Signal switching unit 14 Decoder 15 Receiving line control unit 16 Radio unit 41-46 Base station 50 Overreach prevention device 111 Press signal Detector 112 Relay controller 113 Contact point 121, 135, 141 Amplifier 122, 144 High pass filter 123 Tone signal generator 131, 132 Switch 133 Timer 134, 145, 151, 152, 159 Inverter 142 Low pass filter 143 Tone signal detector 157 AND Circuit 154 Delay circuit 155 Exclusive OR circuit 156 D flip-flop circuit 158 Exclusive OR circuit 161 Transmitter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04Q 7/24 7/26 7/30 (72) Inventor Kiyoyuki Hatakeyama 3-1-1 Asahigaoka, Hino City, Tokyo 1 TOSHIBA Shimbun System Engineering Co., Ltd.

Claims (6)

[Claims] 1. A train radio system having a plurality of base stations connected to a plurality of command consoles by wires and transmitting and receiving signals, and transmitting and receiving signals to and from any one of these base stations by radio. When wirelessly transmitting a signal from the base station to the train, tone signal adding means for adding a tone signal to be transmitted together with the signal to the head of the transmission signal; and whether a tone signal is added to the received signal. Determining means for determining whether the tone signal has been added to the received signal by the determining means, and control means for performing control not to transmit the received signal to the command console side. A train radio system characterized by comprising: 2. The control unit disconnects a signal line for transmitting a signal to the command console from the base station when the determination unit determines that the tone signal is added to the head of the received signal. The train radio system according to claim 1, wherein: 3. A system which has a plurality of base stations connected to a plurality of command consoles by wires to transmit and receive signals, and which wirelessly transmits and receives signals to and from any one of these base stations, and In a train radio system having a loopback test function of receiving leaked radio waves of a signal transmitted from a base station and transmitting the received signal to the control console, when wirelessly transmitting a signal from the base station to the train, Tone signal adding means for adding a tone signal to be transmitted together with the signal to the head of the transmission signal; determining means for determining whether a tone signal is added to the received signal; If it is determined that the tone signal is added to the command console, control is performed so that the received signal is not transmitted to the command console, and the tone signal is added to the received signal during the loopback test. Wherein the base station is provided with control means for controlling the transmission of the received signal to the command console when it is determined by the determining means that the base station has been added. 4. The control means performs control to disconnect a signal line for transmitting a signal to the command console from the base station when the determination means determines that the tone signal is added to the head of the received signal. 4. The train radio system according to claim 3, wherein if the received signal is a signal at the time of the loopback test, control is performed to keep the signal line connected to the base station. 5. The tone signal adding means according to claim 1, further comprising a setting means for setting a length of the tone signal to be added to the head of the signal within a predetermined range. Train radio system. 6. The method according to claim 1, wherein the tone signal is faHz, and a signal to be transmitted with the tone signal added to the head is transmitted through a high-pass filter having a cutoff frequency faHz. Train radio system.