A new technique for adaptive processing applications, which is superior to the conventional Applebaum-Howells adaptive loop, is presented. The new technique is based on open-loop digital processing and does not have the limitations of the conventional closed-loop analog processor. In contrast with the conventional adaptive loop, the open-loop processor has effectively infinite gain, is unconditionally stable, and does not depend on the power level of the auxiliary signal. Copyright © 1978 by The Institute of Electrical and Electronics Engineers, Inc.