A railway wireless communication terminal based on lte-r

Abstract

The invention discloses a railway wireless communication terminal based on LTE-R. The communication terminal includes an LTE-R signal transceiver module, an uplink transmit signal amplification module, a bidirectional signal isolation module, a main antenna, a secondary antenna, an interference signal suppression module, a first downlink received signal amplification module and a second downlink received signal amplification module. The communication terminal selects a linear power amplifier with a corresponding gain according to its maximum actual transmission power to complete the amplification of the transmission power of the uplink transmission signal, thereby solving the problem of the limited uplink power of the existing railway communication terminal at the edge of the LTE-R network cell , to meet the information transmission conditions of long distance base station spacing in railway. On the other hand, the communication terminal ensures the isolation and leakage ratio of the uplink and downlink signals while improving the transmission power of the uplink transmission signal.

Description

technical field [0001] The invention relates to an LTE-R-based railway wireless communication terminal, belonging to the technical field of railway special communication. Background technique [0002] The railway communication system is the nerve center of the high-speed railway, and it also plays an important role in the operation and maintenance of the railway system, fault warning, danger notification, and emergency rescue. At present, my country's railway mobile communication mainly adopts the GSM-R system (a comprehensive and dedicated digital mobile communication system specially designed for railway communication), which mainly carries train control information, wireless train scheduling, locomotive synchronous control, wireless transmission of dispatching commands, wireless train number Calibration information, vehicle equipment monitoring information transmission and other services. [0003] In order to further ensure the safety of high-speed railway operation, impr...

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Problems solved by technology

[0004] Since the LTE-R network is distributed linearly along the railway, and the construction conditions are limited, the base stations are relatively sparse. The minimum base station distance is 3km, and the maximum base station distance exceeds 6km, resulting in a large distance between railway wireless communication terminals and base stations. The downlink signal received by the railway wireless communication terminal at the edge of the cell is very weak

In addition, the maximum output power of existing railway wireless communication terminals is fixed, and the maximum uplink transmission power is only 200mw (ie 23dBm). When the target receiving power of the base station cell is -67dBm, the railway wireless communication terminal will reach the maximum when the distance from the base station is 1.68km. Transmitting power, therefore, the existing railway wireless communication terminal is difficult to meet the information transmission under the condition of large railway distance between base stations, resulting in the serious limitation of the uplink power of the communication terminal at the edge of the LTE-R network cell, the base station received The uplink signal of the communication terminal is very weak, the signal-to-noise ratio is very low, and it is difficult to demodulate. The uplink rate of the communication terminal is very low, and even dropped, so it is difficult to guarantee the reliability of the railway business

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