Research On ISI Cancellation Technology Based On FTN

With the accelerated usage of wireless mobile communication accelerates and its wide applications in our lives,the shortage of spectrum resources becomes more and more serious.Therefore,the technique of Faster-Than-Nyquist(FTN)transmission came into being.FTN transmission with a higher data rate than Nyquist orthogonal transmission can significantly improve the system capacity and spectrum efficiency,but the inescapable Inter-symbol Interference(ISI)is introduced artificially,thus affects the system error performance.The traditional equalization algorithm used to eliminate ISI in FTN transmission is very complex,and its performance worse than that of orthogonal transmission.Therefore,the interference elimination technology of single-carrier FTN signal is studied in this thesis.Firstly,this thesis introduces the research status of FTN technology in detail and summarizes the similarities and differences between FTN and traditional orthogonal Nyquist transmission technology.Further,theoretical derivation of the Mazo Limit in FTN is carried out.The frequency band utilization ratio and capacity of FTN system are analyzed through simulation.The advantages of FTN transmission technology are illustrated and the forming method of FTN signal waveform is introduced.Secondly,aiming at the problems existing in traditional equalization algorithm,an algorithm based on partial matrix eigendecomposition is proposed.The simulation results show that the proposed scheme can improve the error performance of the system.At the same time,FTN signal receiving technology in multipath channel is studied,and the scheme based on matrix eigendecomposition is optimized in multipath channel.The simulation results show that the error performance of the proposed scheme on the receiver is very close to that of traditional orthogonal transmission.Furthermore,ISI block in matrix calculation scheme is inconsistent with the actual interference length and involves multiplication calculation and correlation inverse calculation of a large number of matrices,resulting in the uncertainty of code element information and high complexity.To solve the above problem,a scheme based on continuous serial interference elimination is proposed.FTN transmission is realized by using the relevant information of the filter and the temporary demodulation value before and after the current code element to gradually eliminate interference.The simulation results show that this scheme can effectively eliminate the ISI introduced by FTN,and is superior to other algorithms in performance,inferior to the matrix eigendecomposition algorithm,but with the lowest complexity.Therefore,the two methods described in this thesis provide a theoretical basis and verification for meeting the requirements of different communication systems in practical application.Finally,the research work of this thesis is summarized and the future research work is prospected.