Effect of Nonlinearity on Receiver Signal to Disturbance Ratio in High Subclutter Visibility.

摘要

Analyses of radar performance usually proceed by assuming a linear receiver. In presence of strong signals, however, actual receivers are subject to saturation effects. This nonlinear behavior can cause a significant change in the statistics of the disturbance. The purpose of this work is to study the effects of the nonlinearity of the radar receiver on the signal-to-disturbance ratio for the case of high subclutter visibility. The signal-to-disturbance ratio (SDR) is maximized using a transversal filter with adaptive weights. Three cases are considered in our research: Case (1): The receiver is linear and the weights of the transversal filter are computed so as to maximize the SDR. This case serves as a baseline against which the others are compared. Case (2): The receive is nonlinear. The weights of Case I are used for the transversal filter. Case 3: The receiver is nonlinear and the weights of the transversal filter are computed so as to maximize the SDR taking into account the effect of the nonlinearity. For all three cases, studies are made to determine how the SDR is affected when the following parameters are varied: (1) shape of the nonlinearity, (2) Doppler frequency, (3) clutter correlation, (4) thermal noise level, (5) clutter power level, and (6) number of pulses. Sensor Fusion, Signal Processing, Algorithms.