  Block diagonalization (BD) based precoding schemes are well-known linear
transmit strategies employed in the downlink of multi-user multiple-input
multipleoutput (MU-MIMO) systems. BD type precoding algorithms employed at the
transmit side effect the suppression of multi-user interference (MUI) by the
decomposition of MU-MIMO broadcast channel into multiple single-user MIMO
(SU-MIMO) channels followed by parallelization of the SU-MIMO channels to
obtain independent streams of each user. Given that the design of linear
precoding algorithms has made significant progress, the implementation of these
techniques in standards for wireless local area networks (WLAN) remains an open
question. In this work, schemes for implementation of BD based precoding
techniques in the framework of IEEE 802.11ac standard are proposed followed by
performance evaluation of these techniques in the proposed framework. I analyze
the sum-rate and the bit-error-rate (BER) performance of the techniques in my
framework and obtain computational complexity-wise as well as performance-wise
optimal algorithm for my system.
