Research On Low Complexity FTN Signal Reception Technology

The continuous expansion of wireless mobile communication applications and the ever-increasing user requirements have led to a sharp increase in the demand for increased wireless transmission rates.However,the available spectrum resources are becoming scarcer,so 5G networks need to rely on new technologies to upgrade the spectral efficiency.As early as 1975,scholar Mazo at Bell Labs had theoretically proved that in the time domain,as long as the reasonable signal is selected,when the symbol transmission rate does not exceed the Nyquist rate by 25%,the minimum Euclidean distance of the signal will not change,that is,the error performance will not be affected.This research theory describes the possibility of non-orthogonal transmission,resulting in a signal transmission technique of Faster-Than-Nyquist(FTN).FTN technology allows symbols to be transmitted at FTN rate.Compared with traditional orthogonal transmission technology,FTN transmission system has greater system capacity and frequency band utilization,but artificially introduces infinitely long inter symbol interference(ISI).The relevant interference cancellation and other receiving techniques are required in the receiver in order to effectively combat ISI,which makes the implementation of the receiver more difficult.The complexity of the receiver of the FTN transmission system is studied in this paper.First of all,the research background and significance of FTN technology,and the current research status of domestic and foreign countries.Then,the basic theory of FTN transmission technology is studied,and the Nyquist criterion under orthogonal transmission system is described.According to the criterion,the basic concept of FTN transmission is introduced.Then,the derivation of the Mazo boundary in the FTN system,the system capacity of the FTN system,and the frequency band utilization of the FTN system are studied.Then,three FTN systems based on interference cancellation-serial interference cancellation algorithm,Viterbi sequence demodulation algorithm and BCJR demodulation algorithm are studied.The analysis shows that the serial interference cancellation algorithm is less complex,but the BER performance is not as good as the Viterbi sequence demodulation algorithm and the BCJR demodulation algorithm.Then,the FTN systems based on equalization technology,including time domain equalization algorithm and frequency domain equalization algorithm,are studied.The analysis shows that the algorithm complexity of time domain equalization is lower than that of frequency domain equalization,but the error performance is not as good as the frequency domain equalization algorithm.Finally,the channel coding and decoding techniques of FTN system,including LDPC code,Turbo code and TPC code,are studied.The error performance of FTN systems with different error correction codes is analyzed in detail.