Research Of The Channel Measurement, Data Processing And Channel Modeling On Wideband Wireless Channel In The High-Speed Environnment

With the development of high speed railway (HSR), there are several challenges occurred in the next mobile communication system. They are related to the transmission rate, bandwidth, speed, adaptive and QoS as a result of the higher speed and larger Doppler shift. LTE-R is considered as the next generation of communication system in HSR, and it will be gradually applied in the Railway Private Network system. The measurement and modeling of channel characteristics in HSR is one of the basic work of HSR wireless communication system study. And thus it becomes the current research focus. This paper gives deep research into the broadband wireless channel measurement scheme, data processing method, and channel modeling on HSR.This thesis firstly discusses the fading properties of wireless channel and introduces some channel parameters, such as the path loss (PL) exponent, shadow fading (SF), delay spread, frequency extension, time dispersion and frequency dispersion parameters. In order to obtain channel parameters in HSR, this paper introduces the wireless channel measurement method and the measurement system, in view of limitations and difficulties of channel measurement in HSR scenarios. Combined with the coverage program in HSR, we select Harbin-Dalian dedicated railway line as our measurement scenarios including plains, hilly terrains, viaducts and open areas.The main work of this paper is extraction and optimization of the wireless channel parameters. Linear models on the basis of the empirical log-normal path loss model for different HSR scenarios are derived, meanwhile, statistical normal distribution of shadow fading are also provided. Then, the number of multipath, together with the root mean square (RMS) delay spread, are analyzed. Based on the results, we demonstrate the channel characteristics under different HSR scenarios. This paper also proposes a novel wavelet-based denoising method which aims to improve the SNR of the channel impulse response, improve the accuracy of the parameter extraction and channel modeling.