The Research Of DOA Estimation Algorithm In CDMA Mobile Communication Systems

The Smart antenna is one of the key technology in the third generation(3G) system And it has been the present focuses in signal processing field. The Smart antenna ,which is adapted in the wireless mobile communication system, in fact, forms an antenna with a high gain. Thus communication in all directions can be proceeded, then base station antenna coverage, system capacity and service quality are improved, also inter-symbol interferes and multi-access interfere are reduced. The space division multiple access(SDMA) is introduced, and users can be distinct from each other through their special location. So the DOA of users plays a very important role in smart antenna systems. The main work of this dissertation is summarized as:1. A new improved ESPRIT-MUSIC algorithm is put forward on the base of the traditional ESPRIT and MUSIC algorithm. This new algorithm utilizes eigenvalue decomposition of ESPRIT algorithm and the space spectrum estimation of MUSIC algorithm, which improves the performance of DOA estimation compared to MUSIC algorithm, and brings flexibility in comparison with ESPRIT algorithm. The simulation results show the validity of this algorithm.2. A novel 2-D ESPRIT method based on three orthogonal linear arrays is proposed to estimate 2-D DOA of different users. This method utilize one of the three linear arrays to pair the 1-D DOA which is estimated by the other two liner arrays respectively. The simulation results show the effectiveness of the method.