Beamforming Algorithms In Smart Antenna Technology

The smart antenna technology is one of the key technologies in future wireless mobile communications, but also domestic and international hot research topic. Wireless mobile communication system, how to eliminate the multiple access interference, co-channel interference, multipath fading and delay spread caused by crosstalk between symbols factors become the major factors considered by the people to improve system performance. Smart antenna adaptive array processing techniques to produce a directional beam, the incident signals on the desired direction to achieve enhanced interference suppression signal in space, resulting in improved signal to noise ratio of the desired signal and system capacity.In this paper, the focus of analysis and research on smart antenna adaptive beamforming algorithms, in the typical adaptive algorithms to select better performance, to achieve a simple, convenient application of the LMS algorithm as a breakthrough, affect the performance of the algorithm with fixed step length analysis to identify the step of the algorithm convergence rate, steady state error as well as disorders of the relationship between, and introduce two kinds of variable step size adaptive beamforming algorithms:that is, normalized least mean square algorithm (NLMS) and the variable step size least mean square algorithm (CLMS). Derived through analysis and MATLAB simulation:the same signal transmission environment, the NLMS algorithm and CLMS algorithm in convergence speed, steady-state error and offset amount is better than the LMS algorithm, thereby demonstrating the superiority of the new algorithm.