Active noise canceling: Structures and adaption algorithms

Some of the main problems present in active noise cancellations are the feedback distortion due to the acoustic feedback between the cancellation speaker and the input microphone; the high computational complexity when recursive least square algorithms are used; and the secondary path estimation. This chapter presents a review of some successful solutions to these problems, such as a hybrid structure to reduce the feedback distortion; active noise cancellation (ANC) FxRLS algorithms in which the filter input signal is decomposed into a finite number; and mutually near orthogonal signal components, as well as successful secondary path estimation algorithms. Computer simulation results confirm the desirable properties of presented ANC structures.