LMS自适应滤波器干扰方法

摘要

自适应滤波器能有效地提高雷达在复杂电磁环境下的适应能力，在雷达信号处理机中得到广泛的运用，其核心是使用自适应算法，将滤波器设计成根据目标对照射信号的响应，及外界的电磁环境的变化等因素，调节滤波器的自身结构参数，最终趋于稳态的维纳滤波器，实现对目标的最优检测。文中主要分析LMS自适应算法中存在的步长固定等缺点，设计干扰信号，并用计算机仿真验证其对LMS滤波器的干扰效果，该干扰信号可使自适应滤波器无法实现结构上的自动优化，降低其雷达的工作效能。%The adaptive filter, which can effectively increase the ability of the radar to adapt to the complicated electromagnetic environment, is widely used in radar signal processing. Its core technology is to design the filter on the basis of the response of the target to the illumination signal as well as the change of the electromagnetic environment so that it can adjust its structure parameter and finally present itself in a stable state. In this paper, the basic principles of the adaptive filter and the LMS algorithm are introduced. Then the defects of the LMS algorithm are presented. On the basis of this a jamming waveform is designed and analyzed. Finally, the jamming effect of the wave on the LMS algorithm is simulated with Matlab. The jamming waveform prevents the adaptive filter from auto- mation and therefore degrade the performance of the radar.