“…Conventionally implemented oblique projectors [18,19] are constructed beforehand on the basis of a priori knowledge about a Correspondence to: Ryudo Nagase. E-mail: h27154a8@edu.teu.ac.jp *School of Computer Science, Tokyo University of Technology, Tokyo 192-0982, Japan **Department of Management Science, Tokyo University of Science, Tokyo 125-8585, Japan both the structured desired signal and interference subspaces in a dynamic environment.…”