Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequen...Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequency (IF) estimation will be affected by some factors such as basis functions. Focusing on this problem, the optimal basis function of TVAR model for the IF estimation of the LFM signal is obtained in this paper. Besides the depth and width of notching, the phase properties of notch filter affect the Signal-to-Interference plus-Noise Ratio (SINR) of correlation output to the narrowband jammer suppression in DSSS, in response to the problem the closed solution of correlation output SINR improvement has been derived when a single frequency jammer passes through direct IIR notch filter, and its performance has been compared with those of five coefficient FIR filters. Later, a novel method for LFM jammer suppression based on Fourier basis TVAR model and direct IIR notch filter is proposed. The simulation results show the effectiveness of the proposed method.展开更多
针对网络化控制系统(NCS)中的随机时变时延,采用自行开发的基于应用层的测试软件,按照IETF(The Internet Engi-neering Task Force)的RFC2544规范,进行了6个多月实际测量,获得了170余万个网络时延数据;通过对实验数据进行相关分析,建立...针对网络化控制系统(NCS)中的随机时变时延,采用自行开发的基于应用层的测试软件,按照IETF(The Internet Engi-neering Task Force)的RFC2544规范,进行了6个多月实际测量,获得了170余万个网络时延数据;通过对实验数据进行相关分析,建立了网络时延的自适应自回归(AR)模型;并用自适应最小均方差(LMS)算法对实测的网络时延进行了估计和预测,实验结果表明了算法的有效性。展开更多
基金Supported by the Natural Science Foundation of Hebei Province (F2010000442)
文摘Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequency (IF) estimation will be affected by some factors such as basis functions. Focusing on this problem, the optimal basis function of TVAR model for the IF estimation of the LFM signal is obtained in this paper. Besides the depth and width of notching, the phase properties of notch filter affect the Signal-to-Interference plus-Noise Ratio (SINR) of correlation output to the narrowband jammer suppression in DSSS, in response to the problem the closed solution of correlation output SINR improvement has been derived when a single frequency jammer passes through direct IIR notch filter, and its performance has been compared with those of five coefficient FIR filters. Later, a novel method for LFM jammer suppression based on Fourier basis TVAR model and direct IIR notch filter is proposed. The simulation results show the effectiveness of the proposed method.
基金国家自然科学基金(the National Natural Science Foundation of China under Grant No.60674057)
文摘针对网络化控制系统(NCS)中的随机时变时延,采用自行开发的基于应用层的测试软件,按照IETF(The Internet Engi-neering Task Force)的RFC2544规范,进行了6个多月实际测量,获得了170余万个网络时延数据;通过对实验数据进行相关分析,建立了网络时延的自适应自回归(AR)模型;并用自适应最小均方差(LMS)算法对实测的网络时延进行了估计和预测,实验结果表明了算法的有效性。
