JP5401516B2 - Wireless communication device and train control system using the same - Google Patents

Description

  The present invention relates to a radio communication device and a train control system using the same.

  As a background art in this technical field, there is JP-A-2007-124215 (Patent Document 1). Although this publication does not clearly indicate that the communication device is wireless, there is a description that the communication on the network is monitored, the frame to be monitored is analyzed, and output in association with the session information. Moreover, there exists WO2007 / 049547 (patent document 2). This publication aims at discriminating interference signals coming from different radio stations at random timing. In order to achieve this purpose, as a method for preserving the feature value of the interference signal included in the received signal, a feature value calculating step for obtaining the feature value of the received signal and the possibility that the desired signal is included in the received signal are determined. A received signal determining step for determining that the received signal is an interference signal when it is determined that the received signal is not likely to include the desired signal, and the received signal may be included in the received signal in the received signal determining step. In the case where it is determined that there is no interference signal feature quantity storage step, the feature quantity of the received signal is stored as an interference signal feature quantity.

JP 2007-124215 A WO2007 / 049547

  Patent Document 1 describes a mechanism for monitoring communication on a network. However, in Patent Document 1, there is a description that a communication on a network is monitored, a frame to be monitored is analyzed, and output in association with session information. However, there is no description that signal data is digitally sampled and recorded. Information for determining whether or not an error has occurred due to an external factor such as interference is not obtained.

  Patent Document 2 describes a mechanism for storing the feature amount of an interference signal. However, since Patent Document 2 stores only the feature amount of the interference signal and does not record the signal data itself, information for determining whether or not an error has occurred due to external factors such as noise and interference is obtained. I can't.

  Therefore, the present invention provides a mechanism for outputting information for determining whether or not a generated communication error is caused by an external factor such as noise or interference.

  In order to solve the above problems, for example, the configuration described in the claims is adopted.

  The present application includes a plurality of means for solving the above-described problems. To give an example, a data recording unit that records a received radio signal, an error determination unit that determines a radio signal reception error, and a communication time An error information recording unit that records error information, and a data output unit that outputs a radio signal and the error information, and when the error determination unit determines that the reception of the radio signal is an error, the data recording unit Is a wireless communication apparatus in which a wireless signal is recorded, an error information recording unit records error information, and a data output unit outputs a wireless signal and error information.

  According to the present invention, when a wireless communication error occurs, it is possible to obtain information for determining whether the error factor is due to an external factor such as noise or interference.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is an example of the block diagram of a radio | wireless communication apparatus. It is an example of the flowchart explaining the process of a radio | wireless communication apparatus. It is an example of the table which stores a radio signal. It is an example of the table which stores error information. It is an example of the radio signal and error information display of a data output part. It is an example of the block diagram of a radio | wireless communication apparatus. It is an example of the flowchart explaining the process of a radio | wireless communication apparatus. It is an example of the packet format of a radio signal. It is an example of an error log and an error information table. It is an example of a radio signal and error information display. It is an example of a lineblock diagram of a train control system. It is an example of the flowchart explaining the process of a train control system. It is an example of a radio signal and error information display.

  Hereinafter, a plurality of embodiments will be described with reference to the drawings.

  In the first embodiment, an example of a wireless communication apparatus that outputs a wireless signal and error information will be described.

  FIG. 1 is an example of a configuration diagram of a wireless communication apparatus according to the first embodiment. The wireless communication apparatus includes a reception processing unit 101, an error determination unit 102, a data recording unit 103, an error information recording unit 104, and a data output unit 105. The reception processing unit 101 digitally samples the received radio wave and outputs it as a radio signal 107 to the data recording unit 103. The received radio wave is demodulated and output as received data 106 to the error determination unit 102. The error determination unit 102 receives the received data 106 as an input, and performs an error determination process on the received data 106. Further, the error determination unit 102 outputs the result of the error determination process to the error information recording unit 104 as error information 108. The data recording unit 103 receives the wireless signal 107 as an input and records it on a recording medium such as a memory. The error information recording unit 104 receives the error information 108 as an input and records it on a recording medium such as a memory. The data output unit 105 receives the radio signal 107 and the error information 108 as inputs and displays them on a display device or the like.

  FIG. 2 is an example of a flowchart for explaining processing of the wireless communication apparatus. After the power is turned on, the wireless communication device starts waiting for reception of a wireless signal (201). The reception processing unit 101 detects the radio signal 107 by detecting an increase in received power or the like (202). If the radio signal 107 cannot be detected, the reception processing unit 101 continues to wait for reception (201). When the reception processing unit 101 detects the wireless signal 107, the data recording unit 103 starts recording the wireless signal 107 (203). The reception processing unit 101 performs demodulation processing and decoding processing of the radio signal 107 (204). After the reception process is completed, the error determination unit 102 performs an error determination process (205). If the error determination result is normal, the data recording unit 103 rejects the recorded wireless signal 107 (206). If the error determination result is not normal, the error determination unit 102 determines a reception error (207). Then, the error information recording unit 104 stores the error information 108 output by the error determination unit 102 (208). Then, the data recording unit 103 stores the wireless signal 107 (209). The data output unit 105 receives the wireless signal 107 from the data recording unit 103, receives the error information 108 from the error information recording unit 104, associates the wireless signal 107 with the error information 108, and displays them to a display device, an external interface, or the like. Output (210).

  FIG. 3 is an example of a table that stores the radio signal 107. The wireless signal data storage table 301 stores data obtained by digitally sampling wireless signals. The vertical axis represents frequency, the horizontal axis represents time, and the value stores the power value. The wireless signal data storage table 301 shows an example in which an arbitrary frequency bandwidth is discretized into m steps. Similarly, an example in which an arbitrary time width is discretized into n steps is shown. As the power value, a quantized digital value is stored. With this table, the radio signal 107 digitally sampled on the frequency axis and the time axis can be recorded.

  FIG. 4 is an example of a table that stores the error information 108. The error information storage table 401 stores at least n communication times and error information. As the communication time, for example, the time when the reception processing unit 101 performs reception processing is stored. The error information 108 stores the number of bit errors of the received data 106 as an example.

  FIG. 5 is an example of the display of the radio signal 107 and error information 108 of the data output unit 105. The wireless signal data display 501 is an example of displaying the wireless signal 107. The vertical axis represents frequency and the horizontal axis represents time, and the magnitude of the received power is expressed by the intensity of the display color. In the wireless signal data display 501, a signal having a narrow frequency bandwidth is a desired wireless signal, and a signal having a wide frequency bandwidth is an undesired interference signal. In other words, the radio signal data display 501 represents a state in which an interference signal collides with a desired radio signal. The error information display 502 is an example of displaying the error information 108. The error information 108 related to the radio signal 107 received at the communication time shown in the error information display 502 is shown.

  With the configuration described above, a radio signal at the time of reception error and output of error information can be obtained. Further, the error information and the radio signal that has caused the reception error can be associated with each other. As a result, it is possible to acquire data for determining whether the cause of the reception error is due to the interference signal or not.

  In the second embodiment, an example of a wireless communication apparatus that can not only output a radio signal and error information but also associate a radio signal and error information and output the number of times of reception of an interference signal will be described.

  FIG. 6 is an example of a configuration diagram of a wireless communication apparatus according to the second embodiment. The wireless communication apparatus includes an antenna 601, an RF unit 602, an ADC 603, a synchronization processing unit 604, a demodulation processing unit 605, a decoding processing unit 606, an error correction unit 607, a CRC check unit 608 (corresponding to the error determination unit 102 of the first embodiment), A packet detection unit 609, a data recording unit 610, a time recording unit 611, an interference number counter 612, an error information recording unit 613, an error log creation unit 614, and an external interface 615 are configured. Here, the antenna 601, the RF unit 602, the ADC 603, the synchronization processing unit 604, the demodulation processing unit 605, the decoding processing unit 606, and the error correction unit 607 correspond to the reception processing unit 101 in the first embodiment. The CRC check unit 608 corresponds to the error determination unit 102 of the first embodiment.

  The antenna 601 amplifies the power of the incoming radio signal and sends it to the RF unit 602. The RF unit 602 down-converts the frequency of a radio signal, which is an electric signal in a high frequency band, and converts it to a low frequency band signal (baseband signal). The baseband signal is digitally sampled by the ADC 603, and the radio signal 107 converted into digital data is output. The synchronization processing unit 604 corrects the frequency and phase of the radio signal 107. The demodulation processing unit 605 performs demodulation processing on the corrected radio signal 107 and outputs encoded reception data 106. The decoding processing unit 606 performs a decoding process on the encoded reception data 106 and outputs the reception data 106 including a bit string corresponding to the original information. The error correction unit 607 performs error correction processing on the reception data 106 composed of a bit string, and outputs the reception data 106 after error correction. The CRC check unit 608 performs a CRC error detection process on the error-corrected received data 106, outputs an error detection result (error information), and outputs the received data 106. The packet detection unit 609 performs processing for determining whether or not the wireless signal 107 corrected by the synchronization processing unit 604 is a desired wireless signal. The data recording unit 610 records the wireless signal 107 on a recording medium such as a memory. The time recording unit 611 records the reception time of the wireless signal 107. The interference number counter 612 records the number of times that the packet detection unit 609 has not detected the desired radio signal 107. The error information recording unit 613 records the processing results of the decoding processing unit 606, the error correction unit 607, and the CRC check unit 608. The error log creating unit 614 detects the desired radio signal 107 by the radio signal 107 recorded in the data recording unit 610, the reception time recorded in the time recording unit 611, and the packet detection unit 609 recorded in the interference counter 612. Each information of the number of times of failure and the respective processing results recorded in the error information recording unit 613 is received, and an error log in which each information is associated is created. The external interface 615 receives the error detection result of the CRC check unit 608, the received data 106, and the error log created by the error log creation unit 614, and outputs them to an external device including a data output unit such as the data analysis / display device 1003. .

  FIG. 7 is a flowchart illustrating an example of processing performed by the wireless communication apparatus according to the second embodiment. After the power is turned on, the wireless communication device starts waiting for reception of a wireless signal (701). The synchronization processing unit 604 detects the radio signal 107 by detecting an increase in received power or the like (702). If the wireless signal 107 cannot be detected, the synchronization processing unit 604 continues to wait for reception (701). When the synchronization processing unit 604 detects the wireless signal 107, the data recording unit 610 starts recording the wireless signal 107 (703). Further, the time recording unit 611 stores the value of the reception time (704). The packet detection unit 609 detects a known pattern signal called a preamble for the radio signal 107 (705). If the preamble cannot be detected, it is determined as an interference signal (711). If the wireless signal 107 is determined to be an interference signal, the interference counter 612 increments the interference count by +1 (712). The data recording unit 610 stores the recorded radio signal 107 as an interference signal in a recording medium such as a memory (713). The time recording unit 611 stores the recorded reception time as a reception time of the interference signal in a recording medium such as a memory. Thereafter, the process returns to the reception standby start state (701).

  When the packet detection unit 609 can detect the preamble, the demodulation processing unit 605 performs demodulation processing (706). After the demodulation process is completed, the decoding processing unit 606 performs the decoding process (707). After the decoding process is completed, the error correction unit 607 performs an error correction process (723). After the error correction is completed, the CRC check unit 608 performs a CRC check process (708). If the CRC check result is normal, the data recording unit 610 rejects the recorded radio signal 107 (709). The CRC check unit 608 outputs normal reception data 106 to the external interface 615. Returning to the reception standby state (701), one reception process is completed.

  If the CRC check result of the CRC check unit 608 is not normal, the CRC check unit 608 determines that there is a reception error (715). The error information recording unit 613 stores the error information 108 output by the decoding processing unit 606, the error correction unit 607, and the CRC check unit 608, respectively. Then, the error log creating unit 614 associates the error information 108 with the radio signal (716), further associates the reception time with the radio signal (717), and further associates the number of interferences with the radio signal (718). Further, the error log creation unit 614 determines whether or not the difference between the reception time and the interference time is equal to or less than a preset threshold value (719). As a result of the determination, if it is equal to or less than the threshold, it is determined that the recorded interference signal is related to the determined CRC check error, and the interference signal and the interference time are associated with the radio signal (720). Further, the error log creation unit 614 creates the data associated so far as a log (721) and outputs it to the external interface 615.

  FIG. 8 is an example of a packet format of a radio signal. The packet format includes MAC header information 801, data information 802, Reed-Solomon code 803, and CRC code 804. The MAC header information 801 stores information such as destination address information and packet length. The data information 802 stores various information used by the application. An example is train control information used in a train control system. The Reed-Solomon code 803 is a bit string necessary for the error correction unit 607 to perform Reed-Solomon error correction. It is generated by performing Reed-Solomon encoding processing. Note that the Reed-Solomon error correction process is not necessarily required, and error correction using a block code may be used. The CRC code 804 is a bit string necessary for the CRC check unit 608 to perform a CRC check.

  FIG. 9 is an example of an error log and error information table. The error log table 901 includes a number, communication time, error information, radio signal, number of interferences, and interference signal as information. The number represents the number of log data. The communication time represents the time at which communication targeted for logging has occurred. The error information has information shown in the error information table 902. The radio signal is data obtained by digitally sampling the received radio wave. The number of times of interference represents the number of packet detection failures. The interference signal is data obtained by digitally sampling the radio signal when packet detection fails. The error information table 902 includes a number, a reception processing result, the number of Viterbi correction bits, a Reed-Solomon syndrome, a CRC check result, a corrected bit string, and represents information regarding the content of the communication error. The number represents the number of error information. The reception processing result indicates to which step the processing has progressed in each of the reception processing steps 702 to 708. The number of Viterbi correction bits represents the number of bits corrected when the decoding processing unit 606 performs Viterbi error correction as decoding processing. The Reed-Solomon syndrome represents a syndrome value output when the error correction unit 607 performs a Reed-Solomon error correction process. The CRC check result represents the result of the CRC check performed by the CRC check unit 608. The corrected bit number sequence represents information of the bit sequence obtained as a result of the processing of the error correction unit 607.

  FIG. 10 is an example of a radio signal and error information display. The wireless communication device 1001 and the data analysis / display device 1003 are connected by a data line 1002. The wireless signal output from the wireless communication device 1001 and the error information are transmitted to the data analysis / display device 1003 via the data line 1002. The data analysis / display device 1003 displays the received radio signal and error information.

  With the configuration described above, a radio signal at the time of reception error and output of error information can be obtained. Further, the error information and the radio signal that has caused the reception error can be associated with each other. Further, detailed information such as the number of interferences, the number of error bits counted by Viterbi error correction processing or Reed-Solomon error correction processing, and the presence or absence of correction processing can be obtained. As a result, it is possible to acquire more detailed data for determining whether the cause of the reception error is due to an external interference signal or not.

  In the third embodiment, an example of a train control system capable of displaying a radio signal and error information by using the radio communication device shown in the second embodiment and acquiring information on a communication error causing the system stop will be described. .

  FIG. 11 is an example of a configuration diagram of a train control system. The train control system includes a logic unit 1101, a wired network 1102, a gateway 1103, a repeater 1104, an AP (access point) 1105, a train 1106, an STA (station) 1107, and a track 1108. The logic unit 1101 is a digital processing device realized by, for example, a computer or a control board. The logic unit 1101 transmits control information to the train 1106 and receives position information from the vehicle. The wired network 1102 is realized by a metal communication cable such as an optical communication cable or Ethernet (registered trademark). The logic unit 1101 and the repeater 1104 are connected. In addition, the repeater 1104 and the AP 1105 are connected. The gateway 1103 performs processing for connecting a plurality of wired networks 1102. Train control information transmitted by the logic unit 1101 reaches the AP 1105 via the wired network 1102 and the relay 1104. AP 1105 transmits train control information as a radio signal. The AP 1105 is realized by the ground side wireless communication apparatus shown in the first or second embodiment. The train 1106 performs wireless communication with the AP 1105 while traveling on the track 1108. The train 1106 carries the STA 1107. The STA 1107 is realized by the wireless communication device on the vehicle upper side shown in the first or second embodiment. The train control information transmitted by the AP 1105 is received by the STA 1107. The STA 1107 controls the train 1106 based on the received train control information. The STA 1107 transmits the position information of the train 1106 to the AP 1105. The location information received by the AP 1105 is received by the logic unit 1101 via the wired network 1102 and the relay device 1104. The logic unit 1101 creates and transmits the next train control information based on the received position information. Train control is performed by repeating this processing cycle.

  FIG. 12 is an example of a flowchart for explaining processing of the train control system. The train control system starts operation as a system after power-on (1201). When the system starts operation, the logic unit 1101 transmits a downlink message that is train control information at regular intervals (1202). Thereafter, the logic unit 1101 enters a reception standby state for an uplink signal transmitted from the STA 1107 (1203). The downlink message is transmitted from the AP 1105 as a radio signal. The STA 1107 that has received the downlink message transmits the uplink message. The logic unit 1101 determines whether or not the uplink message has been normally received (1204). If the logical unit 1101 normally receives the upstream message, the logical unit 1101 proceeds to the transmission processing of the next downstream message as it is (1202). If the logic unit 1101 cannot receive the upstream message normally, it receives the error log transmitted by the AP 1105 (1205). The logic unit 1101 determines whether the error log has been received five times in succession (1206). If it is not five times consecutively, the log before the five logs received in the past (the log six times before) is discarded (1211). Then, the process proceeds to the next message transmission process (1202). If the logic unit 1101 determines that the error log has been received five times in succession, it is considered that communication with the train 1106 has been interrupted, and emergency stop measures are taken. Here, as an example, five consecutive times are used, but the number of times may be set as appropriate. The logic unit 1101 stores error logs for the past five times (1207), and transmits an emergency stop signal to the train 1106 (1208). Then, an emergency stop alarm is displayed (1209), and the stored error log is displayed on the display device 1301 (1210).

  FIG. 13 is an example of a radio signal and error information display. A display device 1301, a logic unit 1302, and a data line 1303 are included. The display device 1301 displays the error log saved by the logic unit 1302. The logic unit 1302 is connected to the data line 1303. In the third embodiment, the data line 1303 corresponds to the wired network 1102.

  With the configuration described above, a radio signal at the time of reception error and output of error information can be obtained. Further, the error information and the radio signal that has caused the reception error can be associated with each other. Furthermore, when communication between the logic unit and the vehicle is interrupted in train control, the cause of the disconnection can be analyzed by storing and displaying a communication error log. This makes it possible to acquire data for determining whether the cause of the reception error that causes the system stop is due to the interference signal or not.

  In the third embodiment, the ground-side wireless communication device AP1105 and the vehicle-side wireless communication device STA1107 may be the wireless communication device shown in the first or second embodiment, and either one of the wireless communication devices is the embodiment. The wireless communication device shown in 1 or 2 may be used.

DESCRIPTION OF SYMBOLS 101 Reception processing part 102 Error determination part 103,610 Data recording part 104,613 Error information recording part 105 Data output part 106 Reception data 107 Radio signal 108 Error information 201-210,701-722,1201-1212 Each process 301 in a flowchart Wireless signal data storage table 401 Error information storage table 501 Wireless signal data display 502 Error information display 601 Antenna 602 RF unit 603 ADC (analog / digital converter)
604 Synchronization processing unit 605 Demodulation processing unit 606 Decoding processing unit 607 Error correction unit 608 CRC check unit 609 Packet detection unit 611 Time recording unit 612 Interference counter 614 Error log creation unit 615 External interface 801 MAC header information 802 Data information 803 Reed Solomon Code 804 CRC code 901 Error log table 902 Error information table 1001 Wireless communication device 1002, 1303 Data line 1003 Data analysis / display device 1101 and 1302 Logic unit 1102 Wired network 1103 Gateway 1104 Relay device 1105 AP (access point, ground station)
1106 Train 1107 STA (station, on-board station)
1108 Line 1301 Display device

Claims (8)

A modulator that modulates the received radio signal to a low frequency band;
A converter for converting the modulated wireless signal into digital data;
A data recording unit that records the converted radio signal and the radio signal before demodulation ;
An error determination unit for determining a reception error of the wireless signal;
An error information recording unit for recording error information including communication time;
A data output unit for outputting the radio signal and the error information;
When the error determination unit determines that the reception of the wireless signal is an error,
The data recording unit records the radio signal before demodulation ,
The error information recording unit records the error information,
The wireless communication apparatus, wherein the data output unit outputs the wireless signal and the error information.   The wireless communication device according to claim 1,
A processing unit for correcting the frequency and phase of the converted radio signal;
A detection unit for detecting a known pattern signal of the corrected wireless signal;
Have
The detection unit determines that the radio signal is an interference signal when a known pattern signal of the radio signal is not detected.
A wireless communication device. The wireless communication apparatus according to claim 1 or 2 ,
The wireless communication apparatus, wherein the error information and the wireless signal are output to the data output unit in association with each other. The wireless communication apparatus as claimed in claims 1 to 3,
A time recording unit for recording the time when the wireless signal is received;
An interference counter that counts the number of times an interference signal is received;
An error log creation unit that associates the radio signal, the error information, and the number of interferences,
When the error determination unit determines that the reception of the wireless signal is an error,
The wireless communication apparatus, wherein the error log creating unit creates an error log in which the wireless signal, the error information, and the number of interferences are associated with each other. The wireless communication apparatus according to any one of claims 1 to 4 ,
When the error determination unit determines that reception of the wireless signal is normal,
The wireless communication apparatus, wherein the data recording unit rejects the recorded wireless signal. A ground side communication device configured by the wireless communication device according to any one of claims 1 to 5 ;
A vehicle upper side communication device for transmitting train position information to the ground side communication device;
A logic unit that is connected to the ground side communication device through a network and generates train control information based on the position information;
The train control system, wherein the ground side communication device controls the train by transmitting the train control information to the vehicle upper side communication device. In the train control system according to claim 6 ,
A train control system that transmits an emergency stop signal to a train when the logic unit receives the error information a predetermined number of times. An in-vehicle communication device comprising the wireless communication device according to any one of claims 1 to 5 ;
A ground side communication device for receiving train position information from the vehicle side communication device;
A logic unit that is connected to the ground side communication device through a network and generates train control information based on the position information;
The train control system, wherein the ground side communication device controls the train by transmitting the train control information to the vehicle upper side communication device.