Downlink synchronization method and system for vehicle-mounted 5G equipment of high-speed train

Abstract

The invention relates to the technical field of mobile communication, in particular to a downlink synchronization method and system for vehicle-mounted 5G equipment of a high-speed train. The method comprises the steps that user equipment UE sends a connection request to a train interface; after the connection is successful, the UE reads the information through the interface; if the train is in the stop state, a downlink synchronization process is directly carried out; if the train is in a running state, time domain pre-frequency offset compensation is carried out after pre-frequency offset estimation is carried out through a pre-frequency offset compensation module, and then a downlink synchronization process is carried out; according to the obtained cell ID and frame synchronization information, the UE receives and processes a physical downlink broadcast channel in a PBCH processing module to obtain main system information MIB, and cell search is completed. According to the method, apre-frequency offset compensation method is adopted before downlink synchronization, the cell search success rate in a high-speed mobile environment is greatly improved, and simulation results show that the downlink synchronization success rate in a high-speed mobile scene can be improved by 30%-60%.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, in particular to a downlink synchronization method and system for a vehicle-mounted 5G device of a high-speed train. Background technique [0002] In recent years, high-speed railways have been widely developed around the world. In some areas, the speed may exceed 300km / h, such as the Japanese Shinkansen (320km / h), the German Intercity Express (330km / h) and the Shanghai Maglev Train (430km / h), which puts higher requirements on the performance of 5G equipment in high-speed scenarios. [0003] The downlink transmission signal of 5G NR selects Orthogonal Frequency Division Multiplexing (OFDM) signal. OFDM is a multi-carrier modulation technology. Compared with the traditional frequency division multiplexing (Frequency Division Multiplexing, FDM), all subcarriers of OFDM are mutually orthogonal, and spectrum overlap can be performed to a certain extent. Save spectrum resources....

AI Technical Summary

Problems solved by technology

[0004] In order to solve the above-mentioned problems, the present invention aims at the problem of low downlink synchronization success rate of user equipment (UE) in a high-speed train moving environment, and integrates the inherent mechanical speed detection of the train with Beidou satellite / Global Positioning System (Global Positioning System, GPS ) positioning function combined with 5G new air interface NR (New Radio, NR) synchronization process to provide a downlink synchronization method and system for vehicle-mounted 5G equipment of high-speed trains

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