Active noise control

Active noise control is one of the popular method involves the use of signal processor which gives better performance compared to passive noise control. An active noise control system removes the primary noise by providing secondary noise which has equal amplitude and opposite phase of the primary noise based on principle of superposition. This system use sensors and digital signal processor to produce anti noise signal by manipulating the error using an adaptive filter. The use of adaptive filter is necessary when the environment is non stationary and it requires minimum priory information of statistical parameters. Depending on the application, lot many active noise control structures have been employed based on different adaptive algorithm. The most popular adaptive algorithm proposed in various literatures for ANC applications is the filtered-x least mean square (FxLMS) algorithm which is a modified version of the LMS. This Dissertation thesis briefly reviews various active noise control structur