Research On Synchronization Technology Of Satellite 5G Terminal

The development and construction of the National Satellite Internet are in an orderly way,which will enable high-speed transmission and seamless global coverage to meet China's social and economic needs.Therefore,the Ministry of Special Technology,the National Satellite Internet Test System Information Station Project,and the Sky Key Technology of the Space-based Access Network funded by the Development Fund,are both based on the 5th Generation Mobile Conmmunication technology(5G)standard low orbit satellite spaceport technology for research.National satellite Internet is a kind of LEO satellite communication system,so the Signal transmission process will be affected by the majority Doppler frequency offset.In order to reduce the impact,this paper uses the ground 5G initial timing Synchronization algorithm fir reference,and uses the Synchronization algorithm in the Primary Synchronization Signal(PSS),in the PSS detection,the algorithm adds frequency offset of different integer subcarrier spacing(SCS)to the local PSS,thus enlarging the frequency estimation range and reducing the operation time.By simulating the channel gap of the State Grid and comparing with the classical PSS cross-correlation algorithm,the algorithm improves the frequency offset estimation by 1.5dB and evaluates the frequency offset in a small number of times.In the calculation,the piece wise PSS difference cross-correlation algorithm increases the complexity of the algorithm and the operation time of the algorithm,but improve the accuracy of the algorithm.Compared with the classical PSS cross-correlation algorithm,the root mean square error is increased by 1dB.The above algorithm can be used to carry out carrier timing synchronization and frequency offset estimation by DMRS and PTRS,and the results of the two are equalized jointly to obtain more accurate time-frequency offset estimation,Finally,time offset compensation is performed for the next symbol so that the received signal can be demodulated.Finally,the simulation results show that the algorithm.It can detect the synchronization signal in the access process under high dynamic and low SNR environment,and can meet the downlink synchronization requirements of low orbit satellite communication system.The improved initial synchronization algorithm and carrier synchronization algorithm can be applied to the SC terminal,which not only improves the connection speed of the terminal to the low orbit satellite in the daily environments,but also enables the terminal to transmit information stably in some special and harsh environments.At the same time,the simultaneous usurpation of rice and rice is also a crucial step to complete the air port technology in the national satellite Internet communication system.