Theory and performances of the PIRANHA filter

The designed rejection filter is of recursive prediction error (RPE) form and uses a special constrained model of infinite impulse response (IIR) with a minimal number of parameters. The so-called PIRANHA filter is made up of independent cascaded adaptive cells realising high rejection at certain frequencies. The convergent filter is characterised by highly narrow-bandwidth and uniform notches of desired shape. Results from simulations illustrate the performance of the algorithm used in the PIRANHA filter under a wide range of conditions and situations. This paper gives a description of the PIRANHA structure, the mechanism of its interference detection monitoring and the filter stability control. The PIRANHA filter is shown to be an efficient solution for detection, tracking and elimination of multiple high-power CWI and narrowband jammers.