Research And Implementation On Synchronization Technology For Troposcatter Communication System

Troposcatter communication is a way of communication technology via using the microwave's scattering phenomenon.Today,this kind of communication mode is mainly used in point to point communication,where the transmission distance is between 70 km to 600 km.Scatter communication technology was proposed in the 1930's.But,during decades of development and research,most of the results is about scattering channel characteristic,and a littler in terms of application of scatter communication.Because of the high concealment and strong anti-jamming,Scatter communication technology is mainly used in the military communication system,but now it will also have civilian applications.The synchronization of received signal is very important in scatter communication systems.Scatter communication system's performance depends on the performance of the synchronization technology.Because only ensuring the correctly of the received signals,the study of other technologies will become meaningful.Based on the development and communication characteristics of scatter communication system,the synchronization technology in troposcatter communication system was studied in this paper.Firstly,a lot mature technology and literature about troposcatter communication was introduced in this paper.Also,this paper analysised and researched the current popular BWA technology,including OFDM and SC-FDE.Through studing the the synchronous technology at home and abroad,this article do some theoretical analysis and technical arguments about Synchronization algorithm from four fields,including Scattering channel's channel characteristic,SC-FDE's basic technology,MIMO space-time processing technology and Golay complementary sequence.Secondly,in this paper,combining the research purpose and on the basis of many of theoretical analysis,used a wireless communication technology based on MIMO SC-FDE finally.Based on this technique,the processing and mathematical model of the synchronization algorithm is researched.And improving the synchronization algorithm according to the analysis results.Finally,in order to ensuring the feasibility and reliability of the improving synchronization algorithm,not only a large number of simulation analysis was done on the simulation platform,but also applied the improving synchronization algorithm in the FPGA platform.In this paper,three mainly aspects was completed about the synchronous troposcatter communication system technology as follows.Firstly,introducting the adaptive threshold technology to replaced the traditional absolute threshold technology.Secondly,against sliding correlation capture feature,frequency domain correlation algorithms was used in this paper,meanwhile improving the computing speed and reduceing the space resources.Finally,in view of the shortcoming of the traditional non-coherent demodulation timing acquisition algorithm,a better timing acquisition algorithm of coherent demodulation was put forward and realized in this article.