Research On Channel Equalization Algorithm Based On Oversampling

With the rapid development of wireless communication technology in recent years,the requirements for the data transmission rate in the communication system continue to increase.However,the transmission environment of wireless communication is harsh.Nowadays,in most communication scenarios,not only the transmitter and the receiver are There will be a large number of obscurations that cause multipath effects,and the transmitter and receiver may be in high-speed motion causing Doppler effect.Multipath effect will produce frequency dispersion,and Doppler effect will produce time dispersion.This is " "Double dispersion"channel transmission environment.If the communication signal is transmitted in such a channel without any anti-interference technology,the received signal will be severely distorted,which will seriously affect the transmission quality of the communication system.Therefore,it is of great value to study which technology can be used to resist the interference of dual dispersive channels to the greatest extent.In this paper,the existing anti-dual dispersion channel interference technology is researched,and the principle and development status of various anti-interference technologies are analyzed,and the frequency domain equalization technology is selected as the focus of this paper.At present,frequency domain equalization technology can be divided into linear frequency domain equalization and non-linear frequency domain equalization according to its implementation method and structure.Both of these equalization methods can bring benefits to communication systems under dual-selection channels,but The current equalization methods are all done under conventional sampling.This paper proposes a scheme that combines over-sampling technology and frequency-domain equalization technology in the receiver of the communication system.For frequency-dispersed channels,since the channel energy will extend beyond the original signal bandwidth,the over-sampling algorithm is adopted to appropriately relax the equalization.Frequency band,the signal energy that was originally neglected can be properly recovered,and the power of the useful signal can be enhanced,thereby enhancing the equalization effect.First,analyze the dual-dispersion channel model,analyze the propagation process of the signal in the channel and the fading experienced,and analyze the small-scale fading in detail,expounding the frequency dispersion and Doppler spread caused by multipath delay The specific influence of the resulting time dispersion on the signal is analyzed,and the modeling method of the double dispersion channel is analyzed.In addition,a brief summary of the equalization technology is also made,and the ZF criterion and MMSE criterion in linear equalization are studied separately,and the decision feedback equalization in nonlinear equalization is studied emphatically.Next,aiming at the existing single-user and multi-user systems under dual-selection channels,this paper analyzes its principle realization and its signal processing flow,and explains its existing problems and improvement directions.Based on the further improvement of the performance of the communication system,this paper proposes single-user and multi-user over-sampling systems,gives the principle realization of the single-user over-sampling system and the signal processing flow,and illustrates its advantages in the dual-dispersion communication environment.And made a detailed analysis of the equalization method of the oversampling signal,compared the difference between the linear equalization and the nonlinear equalization in the oversampling system,and analyzed the benefits of the oversampling system to the communication performance through both qualitative and quantitative methods.Finally,The simulation verification demonstrates the benefits of oversampling technology in the communication system by constantly changing the channel parameters.On this basis,the multi-user over-sampling system is studied,the similarities and differences between the multi-user over-sampling system and the single-user over-sampling system are discussed,and the performance of the multi-user over-sampling system is analyzed under different channels and different numbers of users.