Research On Interference Suppression Technology Based On DVB-S2 System

Digital Video Broadcasting by Satellite-Second Generation(DVB-S2)is a very flexible standard covering a variety of applications for satellite communications.This thesis research the interference suppression technology based on DVB-S2 system.The target transmitter transmits the DVB-S2 signal,which is omnidirectionally forwarded by the satellite,and the local receiver can receive the DVB-S2 signal.In order to interfere with the target receiver,the local transmitter analyzes its frame format,coding and modulation mode,and transmits the same type of strong power interference signal,while the local receiver receives the interfered target signal,and the local needs to solve the target signal,direct demodulation can not get the target signal,need to do interference suppression.Therefore,studying the interference suppression algorithm has important theoretical and practical significance for this scenario.In this article,we introduce the research status and background of the thesis,and analyzes the research status of interference suppression algorithms at domestic and foreign.Then,in the DVB-S2 scenario,interference suppression is implemented using RLS adaptive filtering,channel estimation,and Fast-Independent Component Analysis(Fast-ICA)signal separation algorithms.A large number of simulations show that the three algorithms achieve good performance under different conditions.The detailed descriptions of this thesis is divided into 6 chapters,as follows:Chapter 1 expounds mainly the introduction part.It introduces the research significance and current situation of the thesis.Firstly,it introduces the history and architecture background of DVB-S2 system.Then it explains the research status of interference suppression technology at domestic and foreign,and gives the main content and structure of the thesis.Chapter 2 presents the DVB-S2 system framework,including transmitter and receiver,and then describes the interference suppression model based on DVB-S2 system,and simulates the performance of the interference signal.Next it describes the interference frame start position detection,carrier synchronization and timing synchronization.Chapter 3 presents the interference suppression algorithm based on the interference reconstruction.This chapter introduces the least squares(LS)and minimum mean square error(MMSE)channel estimation algorithm.Then,the channel estimation algorithm is used in the interference suppression technology of DVB-S2 system.First,demodulates the interference signal,then,through the transmitter,the interference signal is reconstructed by the result of channel estimation,and the interference cancellation is implemented by subtracting the mixed signal.In this chapter,respectively,whether the known interference signal is used for simulation analysis.Chapter 4 presents the interference suppression algorithm based on adaptive filtering.This chapter introduces Recursive least squares(RLS)adaptive filtering algorithm.Take jamming signal as a priori information,continuously training filter tap coefficients.After a while,the coefficient convergence tends to be smooth.Then reconstruct the jamming signal and subtract the received signal to obtain the expected signal.Next,demodulate and obtain the information transmitted by the enemy transmitter.Chapter 5 presents the Fast-ICA algorithm based on signal separation.This chapter describes the Fast-ICA signal separation algorithm.The receiver is adjusted according to the requirements of the algorithm,the two-channel receiver is utilized for signal separation,and the useful signal is demodulated and decoded.Then,the performance of Fast-ICA algorithm is simulated by matlab.Chapter 6 summarizes the work of the thesis,comparing the performance and complexity of the three algorithms in the first three chapters.Then,explain the problems and deficiencies in the work,and give some suggestions and prospects for future work.