Patent ID: 8379879
Filing Date: 2013-02-19
Classification: H04R

Abstract:
1. An active noise reduction system having a microcontroller unit (MCU) for receiving an audio input signal a(n) and a noise interference signal d(n) and calculating an audio broadcasting signal y(n) according to a Feedback Filtered-X Least-Mean-Square algorithm, the active noise reduction system comprising: a first operation unit for receiving the audio input signal a(n) and the audio broadcasting signal y(n), a firs reference signal y a first error operation unit for receiving the noise interference signal d(n) and the audio broadcasting signal y(n), a first error signal e(n) being analyzed with an analytic function of a second error operation unit for receiving the first error signal e(n) and the audio input signal a(n), a second error signal e a second operation unit for receiving the second error signal e a first adaptive operation unit for receiving the first noise prediction signal x(n), the audio broadcasting signal y(n) being analyzed with an analytic function of  wherein μ is a convergence factor; and a second adaptive operation unit for receiving the first noise prediction signal x(n), a second noise prediction signal x′(n) being analyzed with analytic function of wherein S′m and Wl are functions of a Least-Mean-Square algorithm, the definition of S′m being S′m(n+1)=S′m(n)+μa(n−m)e