Abstract: Based on the shortage of the variable step size LMS adaptive algorithm applied in the speed measuring system of blood by laser Doppler technology，an improved LMS adaptive algorithm combined variable step size algorithm and transform-domain algorithm is designed.The simulation results indicate that the algorithm is effective in eliminating disturb that introduced by electro-optic modulator or complicated of body and gaussian noise of yawp，and have simple calculating，better misadjust properly and convergence than others.Precondition of precision，the algorithm has favorable sphere of application.

摘要： 针对变步长LMS自适应算法在激光多普勒血流量检测系统中应用的不足，提出一种基于变换域的变步长LMS自适应算法，通过仿真实验结果表明，本算法可以有效地消除在检测过程中由于光电调制、人体组织组成复杂等引入的多频干扰以及背景高斯噪声信号，并具有算法简单，收敛性强，稳态误差较小的特点，在保证精度的前提下，具有良好的适用范围。