摘要
介绍多普勒频移实际是频谱扩展,等效为衰落信道,限制了低速率数据的传送。当今的2G与3G在列车时速不超过500km时均可以对抗多普勒频移,影响通信的主因是快速瑞利衰落。
Doppler frequency shift is actually spread spectrum,equal to fading channel.It limits low-rate data transport. 2G and 3G system can resist Doppler frequency shift when the speed of the train is less than 500 km/h.The major factor which effects communication is fast Rayleigh Fading.
出处
《邮电设计技术》
2009年第12期1-4,共4页
Designing Techniques of Posts and Telecommunications
关键词
高铁通信
多普勒扩频
衰落信道
High speed railway communication
Doppler spread spectrum
Fading channel
