重叠加窗下卫星直序扩频通信干扰非线性抑制方法OA北大核心CSTPCD

Since the discrete Fourier transform(DFT)involves frequency domain transformation of the signals in the entire window,it may lead to spectrum leakage if discontinuity occurs to the signals at both ends of the window.The overlapping windowing technology can smooth the signals by the overlapping parts of the window,achieve smooth transitions among different time windows,and reduce the impact of frequency leakage and sidelobe effects.Therefore,a nonlinear suppression method for satellite direct sequence spread spectrum communication interference under overlapping windowing is studied in order to improve communication performance.The satellite direct sequence spread spectrum communication signals are divided into two channels,and 1/2 overlapping windowing processing is performed by improving the raised cosine window function.The modulation DFT algorithm is used to transform the windowed 2-channel spread spectrum communication time-domain signals and obtain the frequency-domain signals.Adaptive threshold interference detection algorithm is adopted to interference and suppress 2-channel frequency-domain signals nonlinearly.The improved adaptive amplitude recovery asymmetric algorithm is used to restore the suppressed frequency-domain signals,which is then subjected to inverse transformation processing to obtain the time-domain signals.According to the idea of 1/2 overlapping windowing,2-channel time-domain signals are fused to achieve the nonlinear suppression of communication interference.The experimental results have shown that the proposed method can effectively fulfill overlapping windowing to process time-domain signals in satellite direct sequence spread spectrum communication,which avoids the influence of sidelobe effects and accurately suppresses the interference of satellite direct sequence spread spectrum communication.