The Research Of Smart Antenna For CDMA Wireless Communication

Recently, smart antenna has become a very promising technology for wireless communication, which could enhance the system capacity. This thesis begins with the introduction of the modeling of array signal and wireless channel, as well as the explanation of the fundamentals of smart antenna. Vector channel model is analyzed, and the features of the array receiver under wireless multi-path propagation are illustrated. Second, both the optimized beamforrnkig for antenna array and constant module algorithm are explored. We deeply study the performance of adaptive array under wireless multi-path environment. In addition, the beamforming techniques for CDMA systems are discussed emphatically. The algorithm based on code filtering is deduced in detail theoretically, and the performances such as convergence and bit error rate (BER) are simulated. Meanwhile, we improve a decision-projected algorithm based on Least-Mean-Square (LMS) error. The improved algorithm is combined with Normalized Least-Mean-Square (NLMS) algorithm. Computer simulations are presented detailedly to show the algorithm exhibits excellent convergence, tracking capability, as well as lower BER. Finally, the adaptive beamforming algorithm is designed and realized in TMS320VC5402 DSK board.