中文摘要：

智能天线的一项核心技术是来波方向（DOA）估计。设计物理模型清晰、数学运算复杂度低的DOA估计算法，对于智能天线的工程实现具有重要的意义。本文给出了一种利用TD—SCDMA标准中置序列在基带上实现DOA检测的简单实用的谱搜索方法-MIDOA谱搜索算法。文章首先给出了TD—SCDMA系统8阵元圆阵智能天线系统中置接收机的物理模型，在此基础上导出了与之相对应的数学处理模型，并根据这些数学模型导出了MIDOA谱搜索算法流程图和相应的基带检测MIDOA谱搜索算法。从仿真结果和性能分析可以看出该方法是一种针对TD—SCDMA标准的、简单有效的DOA估计方法；与基于子空间的Music等算法相比，它具有物理模型清晰、算法的稳健度高和可检测的DOA数不受智能天线阵元数的限制等特点。

英文摘要：

The design of direction of arrival （DOA） estimation algorithm is the key technology of smart antennas system. It is very important to design an algorithm of DOA estimation with clear physical model and lower complexity of mathematics process. In this article, a novel spectrum search algorithm, MIDOA spectrum search algorithm, is presented, which is based the feasible use of midam- ble sequence defined in TD-SCDMA standard （TD）, and is one simple practical baseband DOA estimate method. Firstly, we propose the physical model of midamble sequence receiver of TD-SCDMA smart antennas with 8 array element circle formation. Based on the physical model, the mathematics formulations for the receiving process are also presented. Then according to the physical model and the mathematics formulations, we give MIDOA spectrum search algorithm as well as the corresponding flow chart. The simulation results and performance analysis show this method is one simple feasible estimate method of DOA in view of the TD standard. Compared with MUSIC algorithm, the MIDOA spectrum search algorithm is characterized with clear physical model and high robustness. And the number of DOA that can be estimated will not be restricted by the array element number of smart antennas array.