在采用自适应技术抑制直接序列扩频通信窄带干扰过程中,针对频域快速(FastLMS,FLMS)算法收敛速度较慢的缺点,将频域快速算法与变步长技术相结合,提出了一种基于改进的Sigmoid函数的变步长频域自适应BLMS(Variablestep-sizeFLMS,VFLMS)算法.理论分析和计算机仿真结果表明:VFLMS算法除具有FLMS算法的优点外,还具有较快的收敛速度和良好的收敛精度,可以有效地抑制直扩系统中的窄带干扰. In the process of using adaptive technology to suppress the narrowband interference of direct sequence spread spectrum communication, aiming at the shortcoming of convergence speed of FastLMS (FLMS) algorithm, the fast frequency domain algorithm is combined with variable step size technology Based on the improved Sigmoid function, a variable-step frequency-domain adaptive BLMS (VFLMS) algorithm is proposed.The theoretical analysis and computer simulation results show that the proposed algorithm has faster convergence speed and better performance than the FLMS algorithm The convergence accuracy can effectively suppress the narrowband interference in DSSS system.