On the Performance of Prefiltered Pisarenko Estimator for Narrow-Band Interference Suppression

In this paper, statistical analysis of the reformed Pisarenko harmonic decomposition frequency estimator, obtained by minimizing a normalized Least square cost function, is derived. This analysis shows the insufficiency of this estimator. To overcome this pitfall, we introduce a prefilter which has the role of preamplifying the narrow-band component and to approximate the overall system to an infinite impulse response (IIR) filter. This new design permits to take advantage of the ensured convergence obtained by using a finite impulse response notch filter and the high accuracy and selectivity achieved by an IIR filter. In particular, this structure presents good performance in low interference to signal ratio environment. Computer simulations are presented to support the proposed theoretical results.