Analysis of interperiod processing upon on-stationary influence of passive Gaussian clutter

Introduction. Adaptive processing of signals in interference is an actual task for different radio systems. Adaptation is based on optimization of the processing algorithm depending on interference parameters, at that a priori independent interference parameters are replaced with their evaluations according to the adaptive Gaussian approach methodology. The interference parameters evaluation is carried out by classified sampling, at that interference stationarity within the training window is supposed. Aim. To analyze effect of interference instability on adaptive interperiod processing decision statistics, to determine dependence of interference correlation matrix evaluation and decision statistics on location and interference intensity in the training window, to research evaluation of false alarm level at interference jump for postdetection interperiod processing, to analyze effect of interference instability on false alarm level at interperiod processing with adaptation to the interference correlation matrix. Materials and methods. The Rayleigh ratio is applied as an interference instability research method. Applying of the Rayleigh ratio allows to determine character of interperiod processing decision statistics change. A model of interference power stepwise change in the educational window is used as reference data. By means of the Rayleigh ratio, change of sample interference matrix at random location of interference jump and its effect on decision statistics is researched. Results. A common expression is received for relative change of decision statistics, and calculations for the interference extreme positions in the window are carried out. Limits of decision statistics are determined, and it is demonstrated that its maximum increase relative to stationary level does not exceed the value of two, and minimum decrease is inversely proportional to half value of interference intensity jump. For postdetection interperiod processing case, numeric evaluation of false alarm probability values is given. Conclusion. Received results show that relative change of decision statistics proportional to interference intensity jump and to corresponding change of false alarm probability necessitates taking measures on its stabilization.