JPH08125602A - Communication equipment for train - Google Patents

Abstract

PURPOSE: To attain communication with high quality by selecting a 2nd transmission signal subject to spread processing through the use of a 1st transmission signal or a PN code resulting from modulation-processing data to be sent to a ground side and sending the selected signal to the ground so as to combine the spread spectrum(SS) communication excellent in noise resistance and the FSK communication. CONSTITUTION: An on-train transmitter-receiver (b) is provide with a 1st transmission signal generating means 15 applying modulation processing to data to sent to the ground by the FSK or the like to generate a 1st transmission signal, a 2nd transmission signal generating means 11 applying spread processing to the data to be sent to the ground by using a prescribed PN code to generate a 2nd transmission signal, and a transmission means 14 selecting the 1st transmission signal or the 2nd transmission signal and sending the selected signal to the ground. Since two kinds of the transmission equipments adopting the SS communication and the FSK communication are provided to the on-train transmitter-receiver (b) and the signal is sent to the ground, the communication with excellent quality is attained even at a location where transmission environment is insufficient through the use of a same frequency channel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a train communication device,
In particular, the present invention relates to a communication system in which high quality communication can be performed by switching the communication system according to the communication environment condition of the transmission path.

[0002]

2. Description of the Related Art Conventionally, as a train communication device for communicating between the ground side and the car side, a carrier wave is modulated with transmission data by frequency modulation (FSK) or the like to generate a transmission signal, and the transmission signal is generated on the ground. Communication is performed via a loop-shaped antenna laid on the side.

[0003]

However, in the train communication device using the conventional loop-shaped antenna, high-speed communication such as 1200 to 4800 BPS is possible, but when the antenna loop becomes long, noise is generated. May increase and stable communication may be impaired.

Therefore, the present invention has been made in order to solve the above-mentioned drawbacks, and its purpose is to combine spread spectrum (SS) communication excellent in noise resistance and FSK communication to obtain high quality. It is to provide a train communication device capable of high communication.

[0005]

In order to achieve the above object, a train communication device according to the present invention is provided between a ground transceiver provided on the ground side and an on-board transceiver mounted on the vehicle. In the train communication device for exchanging data, the on-vehicle transceiver includes first transmission signal generation means for generating a first transmission signal by modulating data to be transmitted to the ground side by FSK or the like. A second transmission signal generating means for generating a second transmission signal by spreading the data to be transmitted to the ground side by using a predetermined PN code; and the first transmission signal or the second transmission. It has a transmission means for selecting a signal and transmitting it to the ground side. Also, the first
Is selected based on a switching signal from the ground side.

[0006]

In the above structure, the transmitting means transmits the data to be transmitted to the ground side to the FS when the first transmission signal is selected.
Communication is performed by communication modulated by K or the like, and by SS communication in which data to be transmitted to the ground side is spread using a predetermined PN code when the second transmission signal is selected.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment, in which a rail R near a station platform H has a plurality of long loops (four in the illustrated example) of long loops along the rail R. The antennas P1 to P4 are laid, and short and short loop antennas p1 and p2 having a short loop length are laid at positions before and after the long loop antennas P1 to P4. The short and small loop antenna p1 is superposed on the long and large loop antenna P1 located at the left end, and the short and small loop antenna p2 is laid on the right side of the long and large loop antenna P4 located at the right end.

The long and large loop antennas P1 to P4 and the short and small loop antennas p1 and p2 are connected to the ground transceiver a. This terrestrial transceiver a is provided with a well-known FSK communication type receiver, that is, receiving equipment having a function of demodulating a signal received from the vehicle upper side and extracting data from the vehicle upper side.

Further, as described in, for example, Japanese Unexamined Patent Publication No. 5-254434 or No. 254435, the terrestrial transmitter / receiver a spreads data transmitted to the vehicle upper side using a PN code. Data is transmitted from the upper side of the vehicle by despreading the spread signal received from the upper side of the vehicle as well as the transmission equipment that has the function of generating the transmitted signal and transmitting the generated transmitted signal to the upper side of the vehicle. Receiving equipment having the function of extracting

On-board transceiver b mounted on train a
Is provided with receiving equipment for receiving spread signals transmitted from the ground side and transmitting equipment for transmitting data to be transmitted to the ground side to the ground side by selecting either the FSK communication system or the SS communication system. ing.

First, the receiving equipment will be described. When the onboard antenna A1 receives a signal from the ground side, the signal is received by the receiver 1 including a bandpass filter (hereinafter referred to as BPF) and an amplifier circuit.

The output signal of the receiver 1 is divided into two, and one of the output signals is demodulated by the demodulation circuit 2 using the same signal as the carrier wave (fc) used in the terrestrial transceiver a. Therefore, from the demodulation circuit 2, the same PN code (PNi) as the PN code (PNi) used in the terrestrial transceiver a is used.
Ni) is extracted and input to the next correlator 3.

The correlator 3 uses the same PN code (PNi) as the PN code (PNi) used in the ground transceiver a,
The degree of coincidence between both PN codes (PNi), that is, the correlation is detected,
The trigger signal when the correlation is obtained is sent to the ground transceiver a.
Same PN code (PNi) used in
i) is output to a PN code generator (hereinafter referred to as PNG) 4. Therefore, the PNG4 is connected to the correlator 3
When a trigger signal is received from the PN code (PNi), that is, the PN code (PNi) synchronized with the terrestrial transceiver a side can be output to the despreading circuit 5.

Since the other output of the receiver 1 is input to the despreading circuit 5, the despreading circuit 5 outputs a signal containing the transmission data from the terrestrial transceiver a, that is, FS.
The K signal is output. This output signal is filtered through the BPF 6 and then input to the FSK demodulator 7.

In the demodulator 7, demodulation processing is performed using the same signal as the carrier wave fc used in the ground transceiver a, and the data transmitted from the ground side to the vehicle upper side is extracted.

With respect to the extracted data, it is determined based on the data stored in the data analyzer 8 in advance which kind of data the extracted data is. That is,
This extracted data includes various train control data such as speed information and stop information, as in the conventional case, and in the present embodiment device, it also includes switching control data of the switching device described later. ing.

As described above, since the on-vehicle transceiver b in the apparatus of this embodiment is adapted to receive the data from the ground side by SS communication, even if the transmission environment is bad, the reception is excellent in noise resistance. It can be performed.

Next, the transmission equipment of the on-vehicle transceiver b will be described. This transmission equipment is composed of equipment for transmitting data to be transmitted to the ground side by SS communication and equipment for transmitting data by FSK communication similar to the conventional one.

First, the SS communication equipment will be described. The data from the transmission data generation circuit 10 for generating data to be transmitted to the ground such as train number or train type is output to the first FSK modulator 11.

In the first FSK modulator 11, the carrier wave fc '
Is FSK-modulated by the data to be transmitted to the ground side and output to the next spreading circuit 12. The spreading circuit 12 has a PNG
Since the PN code (PNi ′) generated from 13 is input, the FSK-modulated signal is a PN code (PN
The diffusion process is performed in i '). The PNG 13 is a trigger signal when the above correlator 3 detects a correlation, and is a PN code (PN
i ') is output, the terrestrial transmitter / receiver a can easily generate PN code (PNi') synchronization when receiving a spread signal from the vehicle upper side and performing despread processing. You can

The spread signal from the spread circuit 12 is switched by the output of the above-mentioned received data analyzer 8 for switching operation.
It is transmitted to the ground side via a transmitter 14 including a BPF and an amplifier circuit and an onboard antenna A2.

Like the FSK modulator 11, the second FSK modulator 15 uses the carrier wave fc as data such as a train number.
The signal subjected to the SK modulation processing and the FSK modulation processing is switched 1
It is configured to output to 3. The first FSK
The modulator 11 and the second FSK modulator 15 may be integrated into one unit, one of the outputs of which may be connected to the spreading circuit 12 and the other of the outputs of which may be connected to the switch 13.

The switch 13 is the reception data analyzer 8 described above.
When the data of the format to be transmitted to the ground side is SS communication, it is switched as shown by the solid line in FIG. 1, and when the data of the communication format is FSK communication, it is shown by the chain line in FIG. Can be switched to.

More specifically, in a place where there is a lot of noise and the transmission environment is bad, it is required to send data from the ground side to the top of the vehicle by SS communication having excellent noise resistance, and In a place where there is little noise and the transmission environment is good, it is required to send data by FSK communication which has an excellent transmission speed.

In the example of FIG. 1, the train a is moving in the direction of the arrow, and the short and small antenna p2 is used for high-speed data from the vehicle
It is transmitted to the ground by SK modulation. After that, long loop P4
, P3, P2, transmission from the vehicle to the ground is carried out by SS communication according to instructions from the ground. Therefore, even in a place where noise is likely to occur due to the long loop antennas P1 to P4, the ground side can receive accurate data from the vehicle.

The short and small loop antenna p1 is used when sending a large amount of data such as train number data of the train a stopped at the station platform H to the ground side by high-speed FSK transmission. Also in this case, SS to FS is instructed from the ground.
A switching signal to K is sent.

As described above, the apparatus of this embodiment is provided with the two types of transmission equipment of the SS communication system and the FSK system in the on-vehicle transceiver b so as to enable transmission to the ground side. High quality communication can be performed even in a poor transmission environment.

In the above embodiment, the data to be transmitted to the ground side is FSK modulated, but it may be amplitude (AM) modulated or phase (PM) modulated.

[0029]

The train communication device according to the present invention generates the first transmission signal by generating the first transmission signal by modulating the data to be transmitted to the ground side by the FSK or the like to the on-board transceiver. And a second means for spreading the data to be transmitted to the ground side using a predetermined PN code to generate a second transmission signal.
The transmission signal generating means and the transmission means for selecting the first transmission signal or the second transmission signal and transmitting the selected transmission signal to the ground side. It can be transmitted to the other side, and high quality communication can be performed. Moreover, when the first transmission signal or the second transmission signal is selected based on the switching signal from the ground side, the communication format can be selected in accordance with the transmission environment on the ground side. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 a terrestrial transceiver b on-vehicle transceiver 1 receiver 2 modulation circuit 3 correlator 4 PN code generator (PNG) 5 despreading circuit 6 BPF 7 FSK demodulator 8 reception data analyzer 10 transmission data generation circuit 11 1st FSK modulation Device 12 Spreading circuit 13 Switching device 14 Transmitter 15 Second FSK modulator A1, A2 Onboard antenna P1 ~ P4 Long loop antenna p1 ~ p2 Short loop antenna R Railey train

Claims (2)

[Claims] 1. A train communication device for exchanging data between a ground transceiver provided on the ground side and a on-board transceiver mounted on a vehicle, wherein: First transmission signal generation means for generating a first transmission signal by modulating the data to be transmitted to the ground by frequency modulation or the like, and spreading processing of the data to be transmitted to the ground side using a predetermined PN code. A second transmission signal generating means for generating a second transmission signal, and a transmitting means for selecting the first transmission signal or the second transmission signal and transmitting the selected transmission signal to the ground side. Train communication device. 2. The train communication device according to claim 1, wherein the selection of the first transmission signal or the second transmission signal is performed based on a switching signal from the ground side.