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分析了井下无线电波传播特性 ,指出井下无线通信受阻的根本原因在于存在各种衰落 ,主要是多径衰落 .根据扩频通信、分集接收等理论 ,论述了 CDMA( code divison multiple access)通信系统抗多径衰落及其它干扰的能力 ,并将 CDMA码分多址技术应用到井下移动通信中 ,组成了一个抗衰落能力强、智能型移动通信系统—— CDMA移动通信系统 .CDMA技术的应用 ,将彻底改变井下移动通信的现状 ,实现地面、井下全球通
According to the theory of spread spectrum communication and diversity reception, the fundamental reason why the underground wireless communication is blocked is that there are various kinds of fading, mainly multipath fading. According to the theory of spread spectrum communication and diversity reception, Multi-path fading and other interference capabilities, and CDMA code division multiple access technology applied to underground mobile communications, formed a strong anti-fading ability, intelligent mobile communication system - CDMA mobile communication system. The application of CDMA technology, will Thoroughly change the status quo of underground mobile communications, to achieve the ground, underground global pass