中文摘要：

时变信道估计是高速铁路无线通信系统的关键技术,通常利用基扩展模型来逼近时变信道并简化估计参数.经实践表明,现有基扩展模型并不能够满足高速铁路场景中信道估计精度的要求.因此,本文研究了高速铁路场景下快时变信道的信道估计方法,提出一种新型基扩展模型.与现有基扩展模型对比,新型基扩展模型通过挖掘历史测量数据,有效地利用了高速铁路在不同时刻经过同一地点的信道之间具有相关性的特点.基于Jakes模型和高架桥场景中的实测数据,对新型基扩展模型的信道估计性能进行仿真,验证了新型基扩展模型对时变信道的估计更为准确,能够较好应用到高速铁路场景中.

英文摘要：

Time-selective channel estimation is one key technology for wireless communication system of high-speed railways（HSRs）.Basis expansion models （BEMs）are usually used to approximate and simplify the time-varying channel parameters to be estimated.However,the existing BEMs such as complex exponential basis expansion model （CE-BEM）and polynomial basis expansion model （P-BEM）cannot obtain satisfactory channel estimation accuracy for wireless communication systems on HSRs.To solve this problem,the channel estima-tion method for fast time-varying channel under the scenario of high-speed railway was studied and a novel BEM was proposed.Compared with the existing BEMs,the new model,based on the historical measurement data,can effectively utilize the characteristics of the correlation between the wireless channels at different time intervals in the same position on the railway.Based on the Jakes model and practical measurement data from vi-aduct situation,the simulationg was conducted on the channel estimation performance of the new BEM,which verified the new BEM outperformed existing BEMs in time-varying channel estimation.The new BEM can be applied to future wireless communication systems on HSRs.