Implementation of Block Diagonalization Type Precoding Algorithms for IEEE 802.11ac Systems

Among the linear precoding techniques block diagonalization (BD) based schemes are well-known transmit strategies employed in the downlink of multiuser MIMO (MUMIMO) systems. Employing BD type precoding algorithms at the transmit side suppresses multi-user interference (MUI) by converting a MU-MIMO broadcast channel into multiple single-user MIMO (SU-MIMO) channels and then decomposing the SU-MIMO channels into multiple independent parallel sub-channels. Substantial work has been done in designing linear precoding algorithms. However, the use of these techniques in the implementation of WLAN standards is an open question. In this paper both the traditional as well as the recent techniques for precoding are investigated and schemes proposed for their implementation in the framework of 802.11ac WLAN standard.