DS-MSK数字化接收机的自适应抗干扰滤波仿真

为在直接序列扩频-最小频移键控（DS-MSK）数字化接收机中设计和实现抗干扰模块,分析了过采样条件下DS-MSK信号的最小均方误差（MMSE）最优滤波问题,考虑到最优滤波难于直接实现,讨论了用自适应抗干扰滤波（AAJF）来逼近MMSE最优滤波性能.传统的非线性滤波往往假设干扰估计误差功率远小于码片功率,这一条件在工程实现中很难满足,相应的抗干扰性能难以达到.为此,对非线性滤波加以改进,提出了部分解扩非线性滤波（PDNF）.蒙特卡罗仿真表明：PDNF滤波性能明显优于传统非线性滤波,接近MMSE最优滤波性能.

Performance Simulation of Adaptive Anti-Jamming Filtering in DS-MSK Digitalized Receiver

In order to design anti-jamming module of the DS-MSK digitalized receiver,Minimum Mean Square Error(MMSE) optimal filtering of DS-MSK signal is discussed under the circumstance of oversampling.Using the Adaptive Anti-Jamming Filtering(AAJF) to approach the performance of MMSE optimal filtering is studied.In realizing the anti-jamming module,nonlinear filtering cannot work properly with the lack of precondition that the power of interference estimation error should be far below the power of DS-MSK chip.A novel filtering structure named Partly Despread Nonlinear Filtering(PDNF) is proposed to solve the problem aforementioned, which outperforms the classic nonlinear filtering significantly.It is found through Monte Carlo simulation that the output SINR of PDNF filtering is close to the MMSE optimal filtering.