关键词: 直接序列扩频, 频域块LMS算法, 变步长, 窄带干扰

Abstract: For that the traditional frequency domain block LMS algorithm which is used for the narrowband interference suppression in Direct Sequence Spread Spectrum（DSSS） communication anti-jamming system leads to a conflict of convergence speed and steady stage error, a new variable step size FBLMS algorithm is proposed, it is the ratio of the remaining interference of the output signal and the overall noise signal to control the variable step size factor update, as interference is filtered, the step size factor is also reduced, making the DSSS communications jamming system to obtain better suppression interference effect. Firstly, DSSS communications jamming system based on the frequency domain block LMS algorithm is introduced. Then the proposed variable step size FBLMS is analyzed. Finally, simulation comparison of this algorithm and traditional algorithm are carried out. Theory analysis and simulation results show that the VSS-FBLMS algorithm can effectively filter out the narrowband interference. The anti-jamming performance of VSS-FBLMS algorithm can exceed the traditional FBLMS algorithm, convergence rate and steady-state error is also superior to the traditional FBLMS algorithm.

Key words: direct sequence spread spectrum, frequency domain block LMS algorithm, variable step size, narrowband interference