智能天线对SCDMA无线接入系统性能的影响

【作者】 陈新艳；

【导师】 张麟兮；

【作者基本信息】 西北工业大学 ， 电磁场与微波技术， 2004， 硕士

【摘要】 近年来，无线接入系统得到了迅速的发展，用户数目极快的增长起来，同时用户对无线服务的质量、业务种类以及数据传输速率的要求也越来越高，如何更加有效的使用有限的频谱资源成为一个亟待解决的难题。SCDMA无线接入系统是一种全新的无线接入系统，它采用智能天线等新技术作为解决上述难题的有效手段。由于国际电信联盟(ITU)采用TD-SCDMA标准作为第三代移动通信的国际三大标准之一，因此以TDD模式工作的SCDMA无线接入系统代表着未来通信技术发展的方向。 本文基于SCDMA无线接入系统，对智能天线技术做了详细的介绍，并且着重讨论了智能天线系统对SCDMA无线接入系统容量的影响。 在对两大类智能天线系统的介绍中，本文首先讨论了一种以改进的Butler网络实现波束赋形的多波束切换系统，推导了该天线阵的馈电模型并给出了仿真结果；然后，本文对智能天线波束形成算法进行了比较，总结了不同算法的优缺点，并给出具有代表性的算法描述与仿真。 为了具体计算智能天线对系统容量的提高，本文建立了一个系统分析模型分别对无线传播模型、干扰模型等进行了假设，并详细推导和计算了在该模型下SCDMA无线接入系统的容量。分析结果符合SCDMA无线接入系统的实际工作情况。同时为了表述智能天线系统的优越性，本文还给出了当基站使用其它天线系统时，系统容量的变化，并给出了比较结果。 鉴于目前有关SCDMA无线接入系统性能分析的文献资料并不多，因此本文所做的工作十分有意义。更多还原

【Abstract】 During the past years, Wireless Access Network has made a great progress. The number of the subscribers has been increasing rapidly, at the same time, there is a great demand for higher quality service, more kinds of wireless services and much higher data rate service. Therefore, how to use the precious wireless resources efficiently has become an urgent problem. SCDMA Wireless Access Network, the newborn wireless communication system, uses many up-to-date techniques, such as Smart Antennas, to solve the problem. Since TD-SCDMA proposal is one of third-generation telecommunication standard in the world, so the SCDMA access system which working at TDD mode represents the future communication business development.In this thesis, we introduce the Smart Antennas and mainly examine the performance enhancements that can be achieved by employing SA in SCDMA wireless access system.In the part of introduction of Smart Antennas, we discuss the Switched-Beam Arrays realizing by mending Butler Network at first. Then we compare the different beam forming algorithms in SA. Simulations of the beam forming are given in each discuss.In order to examine the enhancements of capacity by employing Smart Antennas, we set up a system-analyzing model, which includes the propagation waste model and interference model. According to the models, we study the capacity of SCDMA system. The simulations and analytical results are reasonable. In the paper, we also discuss the performances by employing different antenna systems. The conclusion shows that the Smart Antennas at the base station can dramatically improve the system performance.Since there is a lack of the researches on performance in SCDMA wireless access network, so the study of the paper is very necessary.更多还原