A method and device for identifying main lobe messages

Abstract

The application discloses a main lobe message identification method and device. When a falling edge of a level signal is detected, a preset timer is started, and when a rising edge of the level signal is detected, the timer is turned off. According to the comparison result of the first value and the second value, it is determined that the message indicated by the first value or the second value is the main lobe message. Due to the change of the level signal, it is only limited by the relative distance between the main lobe and the side lobe in the transponder signal, and the relative distance between the main lobe and the side lobe mainly depends on the radiation characteristics of the vehicle antenna, and is not affected by the vehicle antenna. The installation height of the antenna and the performance limitation of the ground transponder. It can be seen that this application does not need to rely on the absolute width of the side lobe or the main lobe, that is, it does not need to reduce the generation of side lobes, nor does it need to selectively eliminate the signal of the transponder, which can effectively reduce the possibility of BTM misjudging the side lobe as the main lobe. probability, and the probability of misjudging the main lobe as a side lobe, which significantly improves the accuracy of the main lobe message uploaded by the BTM.

Description

technical field [0001] The present application relates to the field of communication technologies, and in particular to a method and device for identifying main lobe messages. Background technique [0002] The balise transmission module (BaliseTransmissionModule, BTM) is the key equipment of the on-board equipment of the EMU. The BTM and the ground balise (used to provide reference for the train positioning) together form the balise transmission system of the train. In the transponder transmission system, information is transmitted between the ground transponder and the vehicle control system through BTM. The 27.095MHz energy signal activates the ground transponder, the BTM receives the modulated signal sent by the ground transponder through the vehicle antenna, the BTM demodulates and decodes the modulated signal, obtains a message, and sends the message to the vehicle control system). [0003] In the process of BTM demodulating and decoding the modulated signal, BTM will ...

AI Technical Summary

Problems solved by technology

[0007] In the first scheme, if the value of the preset threshold is too high, the length of the main lobe of the transponder signal will be shortened, thereby reducing the ability of the BTM to process the transponder signal when the train is running at high speed

In addition, limited by the height of the train bottom (the vehicle antenna of the BTM is installed at the bottom of the vehicle), the installation height of the ground transponder, and the wear and tear of the train wheels, the relative distance between the ground transponder and the vehicle antenna changes dynamically. When the distance approaches a certain level, the value of the preset threshold that can reduce the side lobe may no longer play the role of reducing the side lobe

In this way, the probability of the BTM misjudging the side lobe as the main lobe will increase significantly, and the main lobe message uploaded by the BTM will no longer be accurate, thus affecting the accuracy of positioning data

[0008] In the second scheme, under different application environment conditions, the lengths of the main lobe and side lobes vary widely. If the preset side lobe width is too large, the BTM may misjudge the main lobe as a side lobe. , so that the main lobe will be eliminated, resulting in the loss of the transponder signal. If the value of the preset side lobe width is too small, the BTM may misjudge the side lobe as the main lobe, and the accuracy of the main lobe message uploaded by the BTM cannot be guaranteed. guaranteed, thereby affecting the accuracy of location data

[0009] To sum up, the above two schemes cannot effectively improve the accuracy of the main lobe message uploaded by the BTM, so the accuracy of the positioning data cannot be guaranteed

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