Research Of Narrow-Band Channel Estimation Method Based On Differential Probability

Channel of land mobile wireless communication has time-dependent properties and fading characteristics, and its statistical properties can be described with Rayleigh distribution. But the wireless channel is effected by the movement speed, transmission, bandwidth, scattering environment and carrier frequency. However, channel is an essential component, and channel estimation is a key technology in the communication systems. Estimation accuracy directly affects the performance of the whole system. While the rapid development of wireless communication technology, the development of high-speed rail is also impressive. Enhance of the high-speed rail is an ordeal for wireless communication technology, especially for channel estimation method. There will be a greater Doppler shift and much worse channel environment with the increasing of the speed of mobile stations. How to ensure the quality of communication becomes an urgent problem in the current mobile wireless communication, and the key is to realize channel estimation.In spite of, the existing channel estimations are already quite mature, and classical channel estimation methods include non-blind channel estimation, blind channel estimation and semi-blind channel estimation. Furthermore, common algorithms include least squares, maximum likelihood estimation, minimum mean square error, zero forcing algorithm, linear minimum mean square error and maximum ratio combining and so on. In addition, there are many interpolation methods, such as first-order linear interpolation, second-order polynomial interpolation, the low-pass interpolation, spline interpolation, time domain interpolation. But the existed methods of channel estimation usually have expensive computations with high complexity.Therefore, aiming at these existing problems of channel estimation methods, firstly classify the existing channel estimation methods and have simulations for common algorithms in this paper. Secondly, summarize and analyze the characteristics of the wireless fading channel. And then, we also study the influence of the moving speed of the mobile terminals on fading and propose channel estimation method based on the differential probability under time-varying conditions in this paper. What's more, mainly focus on the time sequential relations of channel gain with probabilistic and statistical properties of time sequential differencing components, and find that the distribution of differencing components of channel gain and the differential probability distribution of time sequential differencing components are being, and the channel gain has timing dependence. From the simulations of combining the time sequential relations of channel gain with probabilistic and statistical properties of time sequential differencing components, we also find that the computational complexity of channel estimation can be reduced.In addition, have a summary and draw conclusions. Besides, have a prospect on the contents and directions that can be done for this method proposed in this paper.