System for dynamically adapting the length of a filter

摘要

A novel system by which the utilization of a central processing unit (CPU) in performing filtering operations can be reduced by shortening the filter's length thus degrading the performance of the system down to a predetermined level or threshold. The present invention is applicable to such systems that incorporate filters whereby shortening their length decreases the performance of the system and to such systems where a reliable quality criteria exists that can be measured during run time. A method iteratively minimizes the filter's length so that the quality criteria does not fall below a predetemined threshold level. In addition, a signal to noise ratio (SN) criteria is suggested for estimating the quality of the reception of communication signals. An implementation is suggested for the method in the particular case of an echo cancellation adaptive filter. In addition, a method for determining an immediate approximation of the echo canceler filter's length as opposed to finding it iteratively.