Abstract
Objective of the methodology presented in this paper is to perform design space exploration on a high level of abstraction by applying high-level transformations. To realize a design loop which is close and settled on upper design levels, a high-level estimation step is integrated. In this paper, several estimation methodologies fixed on different states of the high-level synthesis process are examined with respect to their aptitude on controlling the transformational design space exploration process. Estimation heuristics for several design characteristics are derived and experimentally validated.