A split-band IIR adaptive line enhancer

A new split-band infinite impulse response (IIR) adaptive line enhancer structure is proposed. This structure is particularly attractive because it overcomes a number of the characteristic problems of IIR adaptive filters, such as instability and the additional complexity needed for the generation of the necessary gradient terms to be used in the adaptive algorithm. It is composed of computationally efficient complementary half-band filters, and adaptive notch filters based on numerically robust all-pass filters. Simulation results have verified the improved performance of this new adaptive line enhancer structure when compared with both full-band and conventional FIR filter based sub-band adaptive line enhancers