星上无源互调的分数域稀疏检测与抑制方法研究

As the satellite systems tend to be featuring high power, wide spectrum, and multiple carriers, passive intermodulation has already become an important constraint factor of the development of satellites. Besides, suppression methods of passive intermodulation based on hardware design still have many defect and restrictions. Therefore a further probe about digital signal processing technology achieving real-time passive intermodulation suppression for online satellites is in urgent need. Utilizing the aggregation and sparsity of passive intermodulation signal in fractional domain, we study on sparse detection and suppression techniques of passive intermodulation on satellites in fractional domain which adopts linear frequency modulation signal as a pilot frequency excitation signal and applies digital signal processing technology. This project proposes three algorithms concerning the detection and parameter estimation of multi-component linear frequency modulation signal, passive intermodulation detection based on pilot frequency and adaptive interference cancellation of passive intermodulation in fractional domain, and explores a new theory which contain a set of full and universal methods about the estimation, detection and cancellation of passive intermodulation interference as a consequence.

随着卫星系统向着大功率、多载波和宽频带的方向发展，无源互调干扰已经成为制约卫星发展的重要因素，目前基于硬件设计的无源互调干扰抑制方法仍存在一定缺陷与限制，因此迫切需要探索基于软件算法的无源互调干扰抑制技术，使卫星在轨运行期间能够自主完成无源互调干扰的实时抑制。本课题采用线性调频信号作为导频激励信号，利用其无源互调信号在分数域的聚集性和稀疏性，通过数字信号处理手段研究星上无源互调的分数域稀疏检测与抑制技术。通过研究分数域多分量线性调频信号的稀疏检测与参数估计算法、基于导频信号的无源互调干扰分数域检测算法和无源互调干扰分数域自适应对消算法，探索出一套完整、通用的包括无源互调干扰估计、检测、对消全过程的无源互调干扰抑制新理论与新方法。

随着卫星通信系统向大功率、多载波和宽频带的方向发展，无源互调问题愈发严重，无源互调产物落入接收频带可形成干扰，影响系统性能。无源互调已成为制约卫星发展的重要因素。目前基于硬件设计的无源互调干扰抑制方法仍存在一定缺陷与限制，因此迫切需要探索基于数字信号处理的无源互调干扰抑制技术，使卫星在轨运行期间能够自主完成无源互调干扰的实时抑制。本课题采用线性调频信号作为导频激励信号，利用其无源互调信号在分数域的聚集性和稀疏性，通过数字信号处理手段研究星上无源互调的分数域稀疏检测与抑制技术。通过研究分数域多分量线性调频信号的稀疏检测与参数估计算法、基于导频信号的无源互调干扰分数域检测算法和无源互调干扰分数域自适应对消算法，探索出一套完整、通用的包括无源互调干扰估计、检测、对消全过程的无源互调干扰抑制新理论与新方法。