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机构地区:[1]南京邮电学院通信工程系,江苏省南京市210003
出 处:《电信快报》2005年第3期11-13,共3页Telecommunications Information
摘 要:文章从步行环境移动通信系统的特征、3G标准的比较和扩频增益、无线链路预算及智能天线的作用等方面分析了TD-SCDMA标准可能存在的技术缺陷。TD-SCDMA标准使用2GHz频段,传播衰落较大,穿透能力差,不易做大范围覆盖。标准选用的扩频系数和FDD-WCDMA系统相比,约为1/16,使要求的发功率增大12dB。智能天线的波束方向图覆盖的面较宽,很难满足使用要求,而且性价比较低。无线链路预算结果说明,它只能适用于步行移动环境。Technical drawbacks of TD-SCDMA system are analysed in this paper from many aspects including the characteristics of personal telecommunication system in walking environment, spectrum spread gain and comparison of different 3G standards, radio link budget, and smart antenna, etc. Due to the fact that 2GHz frequency band is used in this standard, it is difficult to have a large coverage area because of large propagation fading and poor penetrability The spectrum spread coefficient selected by the standard when compared with FDD-WCDMA system is about 1/16, making the required transmitting power about 12 dB higher. The coverage of the wave beam direction diagram of the smart antenna is broader than required, and the performance to cost ratio is lower. The result of radio link budget also proves that it is useful for walking environment only.
关 键 词:TD-SCDMA标准 智能天线 扩频 无线链路 WCDMA系统 移动通信系统 频段 2GHz 移动环境 技术缺陷
分 类 号:TN929.533-6[电子电信—通信与信息系统]
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