The Research On The Location Of Interferences In TD-SCDMA System

In recent years, the rapid expansion of mobile communications market has effectively promoted the development of mobile communications, while communications technology has been rapidly developed. Now, in China, the development of the third generation mobile communication has made remarkable achievements and the third generation mobile communication system has also been put into use. TD-SCDMA is presented by our country and has become an international third-generation mobile communications standard. China Mobile has established a nationwide network of TD-SCDMA. At the same time, with the continuous decline in mobile tariff and the users'rising dependence on the mobile phone, China Mobile is focusing on providing high quality services for users. But, now there are a lot of interference devices on the network who are severely reducing the network quality, such as repeater, signal isolator. These devices seriously affected the quality of the mobile communication network in some areas and greatly influenced the talk around the user's perception. Strong interference signals can even cause a number of base station out of service within the region. Therefore, China Mobile has been serious attention to the problem of interference.To make the base station to work properly, these interference sources must be found, and close them. So the exact location of the source of interference has been to ensure the base station to work as a prerequisite. While the TD-SCDMA system uses smart antenna technology, it provides the technical foundation for the realization of intelligent, real-time and quickly interference location. This paper is to solve the interference location problem just using DOA, which is a key technique of the smart antenna. To find the interference sources'accurate position, three main problems need to be addressed. Firstly, the problem is to estimate the number of interference sources. Accurately estimating the number of interference sources is the basis of achieving accurate position of the interference sources. Then, the second problem is studying the DOA technology for a related smart antenna. Finally, make use of several smart antennas and least distance to achieve accurate location of interference sources.This paper studies all these three aspects:1. Propose estimation algorithm for the num of interference sources based on MUSIC algorithm and hypothesis testing;2. Propose the basic model of DOA, moreover propose enhanced algorithm of CBF and Capon on the basis of the model;3. Propose solutions to the virtual intersection issue in multi-target location systems;4. Build a DOA based location system to test all these algorithms. The real field test results show these algorithms are effective.