Adaptive LMS filtering with sigma delta input signals

A structure of an LMS-algorithm which operates directly with ΣΔ (Sigma-Delta) input signals is presented. Decimation of the input signal is thus not required and the proposed filter can be implemented without multiplications. To allow adaptation of the LMS algorithm a filter in the error path is necessary. It will be demonstrated that with a proper choice of this filter the proposed design can almost meet the performance of a PCM-LMS system