【摘要】 本文主要研究智能天线波束形成算法,智能天线是移动通信系统中的关键技术,自适应波束形成算法是智能天线的核心技术,算法的收敛性能和稳态误差及对期望信号的跟踪能力是衡量算法性能的重要因素。经研究最小均方(LMS)算法,本文提出基于双曲余弦函数的变步长LMS算法,通过建立误差ε和步长μ的函数关系,实时调整步长,解决了稳态失调系数和收敛速度的矛盾。matlab仿真结果表示本文算法收敛速度更快,稳态误差更小,对期望信号的跟踪能力更好。仿真结果表明本文算法具有更好的实用性。更多还原

【Abstract】 This paper mainly research the adaptive beamforming algorithm of smart antenna.smart antenna becomes one of the key technologies of mobile communication systems,and Adaptive beamforming algorithm is a crucial technology of the smart antennas. The convergence speed and maladjustment error and the capability of acquisition and tracking of desired signal are main factors to determine algorithm performance. After the least mean square(LMS)algorithm is researched,A variable step least mean square(LMS)algorithm which based on hyperbolic tangent function is proposed in this paper. A function relationship is established between signal error and step size, and the contradiction between convergence speed and maladjustment error is solved. The simulation with MATLAB indicates that the proposed algorithm has faster convergence and smaller maladjustment error and better performance of acquisition and tracking of desired signal . The simulation results prove that the new method has better practicability.更多还原