“…Previous solutions are based on amplitude-only filtering (Dai & Yao, 2008), amplitude and phase filtering (Petropoulos et al, 2001;Weiner, 1995;Azaña et al, 2003), or phase-only filtering (Azaña et al, 2005;Wang & Wada, 2007;Weiner et al, 1993). In term of power efficiency phase filtering is preferred since the energy is totally preserved with respect to amplitude only or amplitude and phase filtering where some spectral components are attenuated or canceled.…”