With the large-scale construction of railroads all over the world especially of China and continuous increase of train speed, the broadband wireless vehicle to land communications under fast moving environment attract the public attention. 随着国际范围内特别是我国铁路的大规模建设和列车速度的不断提高,高速移动环境下的车地宽带无线通信引起了人们的关注。