A novel structure for cascade form adaptive notch filters

The current cascade form adaptive notch filters have two different ways to adjust its parameters. First, each section is adapted individually (AI). Second, all sections are adapted simultaneously (AS). As to the complexity of tracking p sinusoids, the AI structure is linear with p but the AS structure is proportional to p2. However, the AS structure has smaller bias in frequency estimates than that of the AI structure. In this paper, we will make a detailed comparison between the AI and AS structures by using a new prefilter technique. Then, we propose a novel structure which has the same complexity order as AIs and almost has the same lower frequency bias as ASs. Extensive computer simulations have been done to compare the performance of three structures under a wide range of tests. © 1993.