Third-generation Mobile Communication Systems Hollow Multi-user Detection Research

In the 3G mobile communication system, Multiple Access Interference is the main source of interference; so, Multi-user detection as a way to eliminate MAI is focused .Based on the thorough analysis of the smart antenna theory and multi-user detection, this paper introduces a space time detection scheme of embedding the smart antenna array into multi-user detection in CDMA mobile communication system. The main works of the dissertion are as follows.On single path condition, the multi-user detection algorithm is derived on the basis of the minimal square rule and the ML rule. A space-time multi-user detection structure and an adaptive method on CDMA system are proposed. The performance of the algorithms proposed is much better than that of traditional single-user detection. Also using the MMSE rule and the ML rule, we derives an algorithm on condition of asynchronous multi-path, and a space time multi-user detection is proposed. In the meantime, an improvement about the SAGE algorithm is proceeded on the basis of finite alphabet characteristic and pilot information of the 3G communications system.