Multi-vehicle mounted station cooperation cell switching method for train-ground communication under high-speed moving environment

Abstract

The invention discloses a multi-vehicle mounted station cooperation cell switching method for train-ground communication under a high-speed moving environment. The first scheme comprises the following steps of: arranging a vehicle mounted station at the front end and the rear end of a train, wherein the two vehicle mounted stations are mutual communication backups; applying a communication resource for the vehicle mounted station at the rear end while switching the vehicle mounted station at the front end; directly switching to the communication resource applied by the vehicle mounted station at the front end while switching the vehicle mounted station at the rear end; or switching the vehicle mounted station at the rear end by directly using available information acquired by the vehicle mounted station at the front end. The second scheme comprises the following steps of: switching with only the vehicle mounted station at the front end and performing data communication with only the vehicle mounted station at the rear end; applying the communication resource for the vehicle mounted station at the rear end and recording the switching position while switching the vehicle mounted station at the front end; and directly switching to the communication resource applied by the vehicle mounted station at the front end while the vehicle mounted station at the rear end reaches the switching position. The method has the advantages of short switching time, uninterrupted communication during the cell switching and capability of meeting the requirements of the train-ground communication under the high-speed moving environment.

Description

technical field [0001] The invention belongs to the technical field of vehicle-ground communication between a train and a ground base station in a high-speed mobile environment. Background technique [0002] With the construction and development of high-speed railways, railway communication technologies are constantly being updated, and train-ground communication systems in high-speed mobile environments have attracted more and more attention. The continuous construction of high-speed passenger dedicated lines has greatly eased the tension in railway transport capacity. Due to the safety and convenience of high-speed railways, more and more people choose high-speed railways for travel. Therefore, the communication needs of passengers on high-speed trains and train control (train operation) Control) The demand for efficient transmission of information has surged, posing severe challenges to existing communication systems. [0003] The high-speed environment will bring a seri...

AI Technical Summary

Problems solved by technology

[0004] Through the retrieval of existing patents and related technologies, it is found that the existing vehicle-to-ground communication cell handover method in the mobile environment: 1. A mobile communication system based on OFDM (orthogonal frequency division multiplexing) and a handover channel allocation method (CN 101022643A) proposed three channel allocation methods: soft time slot handover, simple macro-diversity handover and enhanced macro-diversity handover. The method proposed in this patent is mainly for improvement on the base station side, which is only applicable to OFDM systems and not to GSM , CDMA and other systems do not have universal applicability, and involve the construction and transformation of many base stations, the cost is high, and the switching delay is long, and it can only be applied to medium and low-speed mobile environments

2. A method for realizing seamless soft handover of wireless video or large data streams in a high-speed mobile environment (CN1801777A) sends encoded data to the data receiving end at one, two or more frequency points, and after receiving the data, the data receiving end Carry out hash cache processing, eliminate duplicate data during multi-channel transmission, and ensure that the data is transparently transmitted from the data encoding section to the data decoding end after the cache processing. This patent can only be used for vehicle-mounted stations (also known as vehicle-mounted mobile stations or Vehicle-mounted mobile station) passively receive, while the vehicle-mounted station cannot send signals, which cannot meet the requirements of interactive communication

[0005] In the research of traditional train-to-ground high-speed wireless communication, in order to improve the handover performance when the train crosses the overlapping area of ​​the cell, the method of expanding the radius of the cell and increasing the overlapping area is mostly adopted, so that the train can have sufficient time to complete the handover process, but due to The increase of the cell radius leads to a decrease in coverage at the edge of the cell, and the received signal quality of users at the edge of the cell will fluctuate greatly due to shadow fading, multipath effects, etc., which will lead to false triggering of the handover process or frequent ping-pong handovers. This will inevitably lead to a decrease in system performance

In some studies, the signal quality in the overlapping area of ​​the cell is improved by arranging relay stations or repeaters in the overlapping area. These improvement measures are conducive to the judgment process of handover triggering. However, in the handover process, most of the original handover mechanisms use The hard handover method (disconnect the connection with the original serving base station first, and then establish a new connection with the target base station), it does not require high complexity for the base station and mobile terminal, but it is disconnected from the original serving base station After the base station, negotiate with the target base station for handover, which will cause communication interruption and decrease in communication quality during the handover

In high-speed train-to-ground communication, on the one hand, train control information needs to be highly reliable, and communication interruption will cause great safety hazards to driving safety; on the other hand, with the increasing demand for communication, communication Interruptions cannot meet people's needs for high bandwidth, high reliability, and low latency in mobile communications

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