Highly non-stationary interference suppression in direct sequence spread-spectrum systems

Non-stationary interference suppression in direct sequence spread-spectrum (DS-SS) systems is addressed. A recently proposed method for the instantaneous frequency (IF) estimation, known as the quasi-maximum likelihood (QML) method, has been used to estimate the interference IF. The obtained IF estimation is in turn used for interference suppression. A significant advantage of the proposed method is that it can handle highly non-stationary interferences. On the other hand, it provides more accurate results than time-frequency-based methods, known for its robustness. The simulations, carried out for interferences characterized by high non-stationarity and high power, prove the effectiveness of the proposed method.