Patent ID: 9728178
Date: 2017-08-08
CPC Classifications: G10K,H03H,H04B,H04M,H04R

Claim:
1. An adaptive filter coefficient update method of receiving a mixture containing a target signal, a particular signal that should be canceled, a stationary noise, and a non-stationary noise, subtracting an adaptive filter output from the above mixture, and obtaining an error signal, comprising: (a) a process of estimating a stationary noise, by a stationary noise estimation unit, from said error signal and obtaining a stationary noise estimated value; (b) a process of estimating a non-stationary noise, by a non-stationary noise estimation unit, from said error signal and obtaining a non-stationary noise estimated value; (c) a process of mixing said stationary noise estimated value and said non-stationary noise estimated value, by a mixing unit, and obtaining a mixed noise estimated value; (d) a process of calculating a coefficient update step size, by a step size calculation unit, such that the coefficient update step size takes a value between 0 and 1 based on said mixed noise estimated value; and (e) a process of updating a coefficient of the adaptive filter, by an update amount calculation unit, by employing the above step size.