3G标准选择研究

3G的主导业务应该是移动因特网业务,它的下行容量应该数倍于上行容量.但早期的3G标准都是上下行信道容量基本对称的系统,存在严重技术缺陷.cdma2000标准已做出重大改进,抛弃了cdma2000 3x标准和CDMA方式,转向时分多址的EV-DO方式.然而WCDMA和TD-SCDMA标准并未做出相应改动.TD-SCDMA标准的多项参数说明它适用于步行移动通信系统,依靠智能天线技术很难改变该标准的基本特征.

Study & Selection of the 3G Standards

Wireless internet service, which should be designed to be the dominant service of 3G, requires down-link capacity several times higher than that of up-link. Initial 3G standards are the systems of symmetric up/ down-link capacity, existing serious technical limitations. Up to now, cdma2000 has already made some significant improvements by discarding cdma2000 3x standard and CDMA mode, then turns its steps to the method of EV-DO, which has TDMA mode; while WCDMA and TD-SCDMA standards have not made any corresponding changes. Needing to be pointed out, several system parameters of TD-SCDMA standard indicate that it is a mobile communication system applying to pedestrian environment. By using smart antenna technology could hardly change the basic features of the standard.