JP4875260B2 - Information transmission method between ground device and on-vehicle device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information transmission method for a railway signal device, and more particularly to an information transmission method between a ground device and an on-vehicle device.
[0002]
[Prior art]
Conventionally, in the information transmission method between railway trains and the ground, noise caused by train current is generated on the track. Therefore, on the Shinkansen etc., control of the speed limit etc. on the carrier wave synchronized with the AC train power frequency from the ground side A system that is resistant to noise by placing information as a modulation signal, transmitting this signal to the track, receiving the signal with a power receiver attached so as to be close to the rail on the upper side of the car, and performing synchronous detection with the train power supply frequency ATC (Automatic Train Control System) is used.
[0003]
The conventional line uses an ATC that transmits and receives a modulation signal that is asynchronous with the train power supply. Recently, a track circuit using a spread spectrum communication method has been studied, and its main purpose is to improve noise resistance.
[0004]
[Problems to be solved by the invention]
However, research on track circuits using the above-mentioned spread spectrum communication method was aimed at improving noise resistance performance, so the establishment of a multiple access method has not been established, and the transmission speed is slow. There was a problem that the amount was small. In addition, there is no information transmission system in practical use as an information transmission system between a railway train and the ground using a spread spectrum communication system, and there is no information transmission system that realizes multiple access.
[0005]
An object of the present invention is to increase the transmission speed of information by establishing a synchronization establishment method and a multiple access method of multiplexed data when applying a spread spectrum communication method to an information transmission method between a railway and a train. That is.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1
Control information such as the speed limit of the train is transmitted from the ground device (for example, the ground device 200 in FIG. 1) to the on-board device (for example, the on-vehicle device 300 in FIG. 1) via the track (for example, the rail L in FIG. 1). In an information transmission method between a ground device and an on-vehicle device for transmission,
At the time of transmission of control information from the ground device to the on-vehicle device, a spread spectrum communication method is applied, and synchronization is established using an M-sequence code having a high autocorrelation (for example, the M-sequence code in FIG. 1). The on- board device multiplex-transmits the control information using orthogonal codes (for example, orthogonal codes A to C in FIG. 1) of square matrices whose elements are either 1 or -1 and whose rows are orthogonal to each other . In order to establish synchronization only with one cycle of received data, the number of correlators equal to the spreading code length included in the received data is configured in parallel .
[0007]
According to the invention of claim 1,
In the information transmission method between the ground device and the on-board device for transmitting control information such as the speed limit of the train from the ground device to the on-board device via the track, the control information from the ground device to the on-board device is transmitted. At the time of transmission, a spread spectrum communication system is applied, synchronization is established using an M-sequence code with high autocorrelation , and the orthogonality is a square matrix whose elements are either 1 or -1 and whose rows are orthogonal to each other. In order to establish synchronization only with one cycle of received data in the on-board device, the number of correlators equal to the spreading code length included in the received data is used. Configured in parallel .
[0008]
Therefore, when the spread spectrum communication method is applied to the information transmission method between the railway ground device and the on-vehicle device, the synchronization establishment method and the multiple access method of multiplexed data can be established, which is more resistant than the conventional information transmission method. The noise performance can be improved, and a larger amount of train control information can be transmitted at a higher speed than before.
[0010]
Further, according to the first aspect of the invention,
In the on-board apparatus, in order to establish synchronization with only one cycle of received data, the number of correlators equal to the spreading code length included in the received data is configured in parallel, thereby decoding multiplexed Data processing speed can be increased.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an embodiment of an automatic train control system 100 to which the present invention is applied. FIG. 2 is a diagram schematically showing the correspondence between the frequency settings f1 to f3 of the synchronization channel and data transmission channel used in the automatic train control system 100, and the code form set for each channel, and the channel configuration. It is. FIG. 3 is a diagram illustrating an example of GOLD sequence data transmitted on the synchronization channel and an example of orthogonal codes transmitted on the data transmission channel.
[0012]
FIG. 1 is a block diagram showing a configuration of a control system of automatic train control system 100 in the present embodiment. In FIG. 1, an automatic train control system 100 includes a ground device 200 and an on-board device 300 mounted on a train.
The ground device 200 includes a data multiplexing conversion unit 201, QPSK (Quadrature Phase Shift Keying) modulation units 202 to 208, spread modulation units 209 to 215, adders 216 and 217, frequency conversion units 218 to 220, It includes local oscillators 221 to 223, an adder 224, and a power amplifier 225.
[0013]
In FIG. 1, train control data (transmission data) in the serial form digitized from the outside shown in the left end portion in the figure is input to the data multiplexing conversion unit 201 in the ground device 200.
The data multiplexing conversion unit 201 is a serial type input from the outside in accordance with the QPSK modulation unit 202 for establishing synchronization connected to the output stage and the six QPSK modulation units 203 to 208 for multiplexing. The train control data is output to the QPSK modulation unit 202 as multiplexed train control data D0 for establishing synchronization, and QPSK modulation units 203 to 203 are used as multiplexed train control data D1 to D6 subjected to multiple conversion processing for multiplexing. It outputs to 208.
[0014]
The QPSK modulation unit 202 generates a four-phase phase modulation signal P0 for establishing synchronization from the multiplexed train control data D0 input from the data multiplexing conversion unit 201 and outputs it to the spread modulation unit 209. QPSK modulation sections 203-208 generate four-phase phase modulation signals P1-P6 from multiplexed train control data D1-D6 input from data multiplexing conversion section 201, respectively, and output them to spreading modulation sections 210-215 To do.
[0015]
The spread modulation unit 209 generates a spread modulation synchronization signal T0 that is a synchronization signal T from the phase modulation signal P0 input from the QPSK modulation unit 202 using an M-sequence code with good autocorrelation, and sends it to the frequency conversion unit 218. Output. The spread modulation unit 210 generates a spread modulation signal A1 from the phase modulation signal P1 input from the QPSK modulation unit 203 using the orthogonal code A having a good cross-correlation and a characteristic that is easy to be multiplexed, and outputs the spread modulation signal A1 to the adder 216 To do.
[0016]
Further, the spread modulation unit 211 and the spread modulation unit 212 use the orthogonal code B and the orthogonal code C having similar characteristics, respectively, from the phase modulation signals P2 and P3 input from the QPSK modulation unit 204 and the QPSK modulation unit 205. The spread modulation signals B2 and C3 are generated and output to the adder 216, respectively.
[0017]
The spread modulation units 213 to 215 have the same functions as the spread modulation units 210 to 212, and the phases input from the QPSK modulation units 206 to 208 using orthogonal codes A to C having the same characteristics, respectively. Spread modulation signals A4, B5, and C6 are generated from modulation signals P4 to P6 and output to adder 217. The orthogonal codes A to C are different orthogonal codes.
[0018]
The adder 216 adds (multiplexes) the spread modulation signals A1, B2, and C3 input from the spread modulation units 210 to 212, and outputs the addition signal (multiplex signal) M1 to the frequency conversion unit 219. The adder 217 adds (multiplexes) the spread modulation signals A4, B5, and C6 input from the spread modulation units 213 to 215, and outputs the addition signal (multiplex signal) M2 to the frequency conversion unit 220.
[0019]
The frequency conversion unit 218 modulates the frequency of the spread modulation synchronization signal T0 input from the spread modulation unit 209 with the local oscillation frequency f1 input from the local oscillator 221 and outputs the frequency modulation signal F1 to the adder 224.
[0020]
The frequency conversion unit 219 frequency-modulates the addition signal M1 input from the adder 216 with the local oscillation frequency f2 input from the local oscillator 222, and outputs the frequency modulation signal F2 to the adder 224.
[0021]
The frequency conversion unit 220 frequency-modulates the addition signal M 2 input from the adder 217 with the local oscillation frequency f 3 input from the local oscillator 223, and outputs the frequency modulation signal F 3 to the adder 224. Note that the local oscillation frequencies of the local oscillators 221 to 223 are different from each other, and the spread modulation synchronization signal T0, the addition signal M1 including the spread modulation signals A to C, and the spread modulation signal over a predetermined frequency band. The addition signal M2 including A to C is diffused.
[0022]
The adder 224 adds the frequency modulation signal F1 input from the frequency conversion unit 218, the frequency modulation signal F2 input from the frequency conversion unit 219, and the frequency modulation signal F3 input from the frequency conversion unit 220. The added signal M3 is output to the power amplifier 225. The power amplifier 225 is connected to the rail L, amplifies the addition signal M3 input from the adder 224 with a desired transmission power, and transmits the amplified signal to the rail L.
[0023]
Therefore, the addition signal M3 transmitted from the ground device 200 to the rail L includes a spread modulation synchronization signal T0 frequency-modulated at the frequency f1, and an addition signal M1 including the spread modulation signals A to C frequency-modulated at the frequency f2. The added signal M2 including the spread modulation signals A to C frequency-modulated at the frequency f3 is multiplexed.
That is, as shown in FIG. 2, a synchronization channel that is frequency-modulated at frequency f1 and includes an M-sequence code, a data transmission channel that is frequency-modulated at frequency f2 and code-multiplexed with orthogonal codes 1 to 3, and a frequency A data transmission channel that is frequency-modulated by f3 and code-multiplexed with orthogonal codes 1 to 3 is set and transmitted to the rail L by the spread spectrum communication method.
[0024]
FIG. 3 shows an example of Gold series data transmitted through the synchronization channel and an example of orthogonal codes transmitted through the data transmission channel.
FIG. 3A is a diagram illustrating an example of Gold series data transmitted through a synchronous channel in the automatic train control system 100 of FIG. In this case, 33 Gold sequences with a period of 31 are employed as the PN code. By setting a synchronization channel using such a Gold sequence code, an M sequence with high autocorrelation can be used for synchronization establishment.
[0025]
FIG. 2B is a diagram showing an example of orthogonal codes transmitted through the data transmission channel in the automatic train control system 100 of FIG. In this case, an orthogonal code with a period of 8 is shown in the form of a determinant. In this case, eight types of spreading codes are obtained by using the numeric strings in each row as spreading codes. If such a spreading code is used to make the code length longer, more orthogonal codes such as period 16 and period 32 can be easily set as spreading codes.
[0026]
The on-board device 300 includes a power receiver 301, a preamplifier 302, frequency conversion units 303 to 305, local oscillators 306 to 308, despreading units 309 to 315, QPSK demodulation units 316 to 322, and a data multiplexing inverse conversion unit 323. Consists of.
[0027]
The power receiver 301 receives the sum signal M3 transmitted from the ground device 200 to the rail L by electromagnetic induction, and outputs the received sum signal M3 to the preamplifier 302. The preamplifier 302 amplifies the addition signal M3 input from the power receiver 301 with a predetermined amplification factor and outputs the amplified signal to the frequency converters 303 to 305.
[0028]
The frequency conversion unit 303 detects the addition signal M3 input from the preamplifier 302 using the local oscillation frequency f1 input from the local oscillator 306, and outputs the spread modulation synchronization signal T0 to the despreading unit 309.
[0029]
The frequency conversion unit 304 detects the addition signal M3 input from the preamplifier 302 using the local oscillation frequency f2 input from the local oscillator 307, and outputs the addition signal M1 to the despreading units 310 to 312.
[0030]
The frequency conversion unit 305 detects the addition signal M3 input from the preamplifier 302 using the local oscillation frequency f3 input from the local oscillator 308, and outputs the addition signal M2 to the despreading units 313 to 315.
[0031]
The despreading unit 309 despreads the spread modulation synchronization signal T0 input from the frequency conversion unit 303 using the same M-sequence code as described above to obtain the phase modulation signal P0, and the phase modulation signal P0 is converted into the QPSK demodulation unit. To 316. The QPSK demodulating unit 316 demodulates the phase modulation signal P0 and adds the synchronization signal T to the orthogonal codes A to C used by the despreading units 310 to 315, respectively.
[0032]
The despreading unit 310 performs despreading from the addition signal M1 input from the frequency conversion unit 304 by using the same orthogonal code A and synchronization signal T as described above to extract the spread modulation signal A1, and the spread modulation signal A1 The phase-modulated signal P1 is reproduced from the QPSK demodulator 317 and output to the QPSK demodulator 317.
[0033]
The despreading unit 311 performs despreading from the addition signal M1 input from the frequency conversion unit 304 using the same orthogonal code B and synchronization signal T as described above to extract the spread modulation signal B2, and the spread modulation signal B2 The phase modulated signal P2 is reproduced from the QPSK demodulator 318 and output to the QPSK demodulator 318.
[0034]
The despreading unit 312 performs despreading from the addition signal M1 input from the frequency conversion unit 304 using the same orthogonal code C and synchronization signal T as above, and extracts the spread modulation signal C3, and the spread modulation signal C3 The phase-modulated signal P3 is reproduced from the QPSK demodulator 319 and output to the QPSK demodulator 319.
[0035]
The despreading unit 313 extracts the spread modulation signal A4 from the addition signal M2 input from the frequency conversion unit 305 by performing despreading using the same orthogonal code A and synchronization signal T as described above. The phase-modulated signal P4 is reproduced from the above and output to the QPSK demodulator 320.
[0036]
The despreading unit 314 performs despreading from the addition signal M2 input from the frequency conversion unit 305 using the same orthogonal code B and synchronization signal T as described above to extract the spread modulation signal B5, and the spread modulation signal B5 The phase-modulated signal P5 is reproduced from the above and output to the QPSK demodulator 321.
[0037]
The despreading unit 315 performs despreading from the addition signal M2 input from the frequency conversion unit 305 using the same orthogonal code C and synchronization signal T as described above to extract the spread modulation signal C6, and the spread modulation signal C6 The phase-modulated signal P6 is reproduced from the above and output to the QPSK demodulator 322.
[0038]
The QPSK demodulation unit 317 demodulates the phase modulation signal P1 input from the despreading unit 310 and outputs multiplexed train control data D1 to the data multiplexing inverse conversion unit 323. The QPSK demodulating unit 318 demodulates the phase modulation signal P2 input from the despreading unit 311 and outputs the multiplexed train control data D2 to the data multiplexing inverse conversion unit 323. The QPSK demodulation unit 319 demodulates the phase modulation signal P3 input from the despreading unit 312 and outputs the multiplexed train control data D3 to the data multiplexing inverse conversion unit 323.
[0039]
The QPSK demodulation unit 320 demodulates the phase modulation signal P4 input from the despreading unit 313 and outputs multiplexed train control data D4 to the data multiplexing inverse conversion unit 323. The QPSK demodulation unit 321 demodulates the phase modulation signal P5 input from the despreading unit 314 and outputs multiplexed train control data D5 to the data multiplexing inverse conversion unit 323. The QPSK demodulation unit 322 demodulates the phase modulation signal P6 input from the despreading unit 315 and outputs multiplexed train control data D6 to the data multiplexing inverse conversion unit 323.
[0040]
The data multiplexing inverse conversion unit 323 performs multiplexed inverse conversion processing on the multiplexed train control data D1 to D6 input from the QPSK demodulation units 317 to 322, respectively, and converts the train control data (received data) in the original serial form. Output.
[0041]
As described above, in the automatic train control system 100 of this embodiment, the spread spectrum communication method is applied to the information transmission method between the ground device 200 and the on-board device 300 to multiplex digitized train control data. In order to make multiple connections, a synchronization signal is generated using an M-sequence code having high autocorrelation, and a spread modulation signal is generated using an orthogonal code that has good cross-correlation characteristics and can take many data types with the same chip length. Generated.
[0042]
For this reason, when applying the spread spectrum communication method to the information transmission method between the railway ground device and the on-vehicle device, it is possible to establish the multiplexed data synchronization establishment method and the multiple access method, which is more than the conventional information transmission method. Noise resistance can be improved, and a larger amount of train control information can be transmitted at a higher speed than before.
[0043]
In addition, in the on-board apparatus, in order to establish synchronization only with one cycle of received data, the number of correlators equal to the spreading code length included in the received data is configured in parallel, so that the decoded multiplex The processing speed of the digitized data can be increased.
[0044]
It should be noted that the number of multiplexing stages in the automatic train control system 100 shown in the above embodiment is merely an example, and it is needless to say that it can be appropriately changed according to the required information transmission capacity specification.
[0045]
【Effect of the invention】
According to the present invention, when applying a spread spectrum communication method to an information transmission method between a railway ground device and an on-vehicle device, a synchronization establishment method and a multiple access method for multiplexed data can be established. The noise resistance performance is improved as compared with the method, and a larger amount of train control information can be transmitted at a higher speed than the conventional method.
[0046]
In addition, in the on-board apparatus, in order to establish synchronization only with one cycle of received data, the number of correlators equal to the spreading code length included in the received data is configured in parallel, so that the decoded multiplex The processing speed of the digitized data can be increased.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a control system of an automatic train control system 100 according to an embodiment to which the present invention is applied.
2 schematically shows the correspondence between the frequency settings f1 to f3 of the synchronization channel and data transmission channel used in the automatic train control system 100 of FIG. 1 and the code form set for each channel, and the channel configuration. FIG.
3 shows an example of GOLD sequence data transmitted through a synchronous channel in the automatic train control system 100 of FIG. 1 (FIG. 3A) and an example of orthogonal codes transmitted through a data transmission channel (FIG. 3A). b)).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Automatic train control system 200 Ground apparatus 201 Data multiplexing conversion part 202-208 QPSK modulation part 209-215 Spreading modulation part 216, 217, 224 Adder 218-220 Frequency conversion part 221-223 Local oscillator 225 Power amplifier 300 On-vehicle Device 301 Power receiver 302 Preamplifier 303 to 305 Frequency converter 306 to 308 Local oscillator 309 to 315 Despreading unit 316 to 322 QPSK demodulator 323 Data multiplexing inverse converter

Claims (1)

In the information transmission method between the ground device and the on-board device for transmitting control information such as the speed limit of the train from the ground device to the on-board device via the track,
When transmitting control information from the ground device to the on-vehicle device, a spread spectrum communication method is applied to establish synchronization using an M-sequence code with high autocorrelation, and the element is either 1 or -1. Multiplex transmission of the control information using an orthogonal code with a square matrix in which each row is orthogonal to each other ,
In the on-vehicle device,
In order to establish synchronization only with one cycle of received data, the number of correlators equal to the spreading code length included in the received data is configured in parallel. Transmission method.

Images