Estimation Of Time-varying Channel Based On High-order Differential Probability

In the wireless communication system,the interference of inter-symbol and inter-channel is inevitable during the wireless signal transmission through the channel because influenced by the factors such as the mobile speed,transmission rate,scattering environment,and carrier frequency of the terminal,which will seriously affect the quality of communication.As the essential part of communication system,the wireless transmission channel and its estimation technology is the key in the wireless mobile communication system,so the accuracy and efficiency of the estimation will directly affect the performance of the entire communication system.With the upcoming era of fifth generation communication,the wireless signal transmission rate and the channel bandwidth are increasing,and the decline of wireless signals in the time domain and frequency domain becomes more obvious.The complexity of the system,the amount and delay of the calculation increases as well.And the energy consumption is more prominent.Therefore it has become one of the research hotspots to study a channel estimation method with low computational complexity and low algorithm complexity.This paper first analyzed the challenges brought about by the increase of carrier frequency in 5G wireless communication technology for wireless channel estimation,and summarized three classical channel estimation methods such as blind channel estimation,semi-blind channel estimation and channel estimation based on pilot signals,and then the propagation mode and propagation characteristics of the signal in the wireless fading channel are analyzed and the statistical characteristics of channel fading are summarized through simulation,and deduced the commonly used zero-forcing equalization techniques and minimum mean-square error equalization techniques.In order to overcome the shortcoming of high-computational in existing estimation techniques,we analyzed the gain of spatial fading and its statistical characteristics of difference and proposed a channel estimation method based on prior differential probability after in-depth study of the characteristics of mobile radio channels.And two improvement strategies are proposed after analyzing the reasons of the parallel points occurrence and excessive tracking in deep fading regions,which reduced the parallel points in the simulation and improve the situation of excessive tracking in deep fading regions.The simulation experiments proved that the improved method is effective.And then we studied the interference caused by guess error on channel estimation,and specified the structure of the transmission signal of each time slot and designed the frame structure of data transmission based on channel estimation in conjunction with the signal transmission rate,and simulated the optimal length of the transmission frame structure under different movement and transmission speed.