| 摘要 |
A method of and an apparatus for identifying a system which allow a filter coefficient to be updated accurately even if noise is mixed. The apparatus for identifying a system includes an adaptive filter (101) for processing a reference input signal to produce an output signal, a subtractor (102) for subtracting the output signal of the adaptive filter from an observed signal, a power estimating circuit (103) for estimating the power of the reference input signal, and a step size determining circuit (104) for determining a step size based on the estimated power of the reference input signal. The step size determining circuit generates a step size according to a function of the power of the reference input signal which monotonously increases if the power of the reference input signal is smaller than a threshold and monotonously decreases if the power of the reference input signal is greater than the threshold. <IMAGE> |
