IEEE 802.11ac/ax: Lessons Learned on OFDM MU-MIMO Transceivers with Realistic Feedback over TGac Channels with Doppler Spread

In this paper, we investigate the effects of channel state information (CSI) compression and feedback delay on the downlink (DL) performance of multi-user multiple input multiple output (MU-MIMO) IEEE 802.11ac systems over dynamic TGac channels with Doppler spread. We show that using degrees of freedom available at receiver side to cancel the MU interference decreases the detrimental effects of CSI imperfections on the performance of 802.11ac wireless local area networks. Fundamentally, we have concluded that iterative real time radio resource algorithms are fundamental to optimize the system configuration since the performance of 802.11ac DL MU-MIMO transceivers depends on a multitude of systems parameters and dynamic random variables.