高速铁路信道小尺度衰落与非平稳特性研究

Research on Small-scale Fading and Non-stationary Properties for High-speed Railway Channels

高速铁路的快速发展使得高速铁路无线信道特性的研究成为热点,但高速铁路信道测量的不易性也使目前的研究工作仍存在不足之处。以北京—天津(京津)城际高速铁路无线信道的具体环境为基础,在平原、车站、城郊3个典型的高速铁路环境中,从两方面深入剖析高速铁路信道的传播特性。一方面,通过莱斯K因子、时延扩展、到达角以及功率角度谱等信道参数,研究高速铁路信道的小尺度衰落特性;另一方面,把以功率相关性为基础的稳态间隔作为特征参数来刻画高速铁路信道的非平稳特性,并基于有限状态的马尔科夫链模型,分析高铁信道多径传播的时变特性。

The research on the characteristics of high-speed railway(HSR) wireless channel has become a hot topic as a result of the rapid development of HSR. However, inadequacies exist in the research due to the difficulties of HSR channel measurement. In this paper, the propagation characteristics of HSR channels in three typical environments including plain, station and suburb were analyzed from two aspects based on the practical measurement data of the wireless channel of Beijing-Tianjin Intercity High-speed Railway. On the one hand, the small-scale fading characteristics of the HSR channels were studied through the channel parameters including the Ricean K-factor, delay spread, angle of arrival and power angular spectrum. On the other hand, the steady-state interval on the basis of the correlation of power was used in this paper to describe the non-stationary characteristics of the HSR channel. The time-varying characteristics of multi-path propagation of the HSR channel were analyzed based on the Markov chain model of finite state.