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SCDMA无线用户环路系统工作于1785-1805MHz频段,它将此段频率分为40条射频信道,每条射频信道的带宽为0.5MHz,供一个子系统使用。它包含32条CDMA码道,这些码道采用直接扩频CDMA技术共用同一条射频信道。每条射频信道中的0码道定义为接入码道,其作用为完成用户终端的初始接入、无线基站呼叫用户终端、无线基站广播系统信息、以及提供系统同步标志等,其它码道用于话音或数据通信等业务,称为业务码道。 此系统之所以具有目前国际上最高的无线频谱利用率,主要是因为采用了以下3种关键技术。
SCDMA wireless subscriber loop system works in 1785-1805MHz frequency band, it divides this section of frequency into 40 radio frequency channels, the bandwidth of each radio frequency channel is 0.5MHz, for a subsystem to use. It contains 32 CDMA code channels, which use direct spread spectrum CDMA technology to share the same RF channel. The 0 code channel in each radio frequency channel is defined as an access code channel, which is used to complete the initial access of the user terminal, the radio base station calls the user terminal, the radio base station broadcasts system information, and provides a system synchronization flag, etc. The other code channels In voice or data communications and other business, known as the business code Road. The reason why this system has the highest international wireless spectrum utilization, mainly because of the following three kinds of key technologies.