Filter coefficient estimation apparatus

摘要

An estimation apparatus predicts filter coefficients for an adaptive filter, the response of which emulates the signal transmission characteristics of a known signal. The response thereto is sent to a signal transmission system of unknown characteristics, enabling execution of calculations without invalidating coefficient updating, even when there is a limit on the word length for processings. To achieve this, a sum of products calculation unit calculates the sum of products of the residual difference in response and the signal which is sent to the signal transmission system. A sum of squares calculating unit calculates the sum of the squares of the signal sent to the signal transmission system over a prescribed period of time. An updating amount calculation unit calculates the filter coefficient updating amounts from the ratio of the results from the sum of the products calculating unit to the results of the sum of the squares calculating unit. Filter coefficients are updated using the coefficient updating amounts calculated by the updating amount calculation unit.