Channel Aware Scheduling in MU-DCF WLANs

Multiple input-multiple output (MIMO) stands for a wide set of multiple antenna technologies, which significantly increase the capacity of wireless networks, without additional bandwidth or transmission power. They are widely recognized as methods that can meet the ever growing network capacity requirements. With a MIMO physical layer (PHY), the transmission channel gets a layered structure, which gives another degree of freedom when scheduling transmissions. Support from higher layers with a cross-layer approach that provides efficient management of the channels spatial layers, can significantly increase the networks performance on both link and system level. A multiple access control (MAC) protocol with the support for multi-user (MU)-MIMO transmissions in ad-hoc WLANs - multi-user-DCF (MU-DCF), has been previously presented. In this paper we introduce channel aware scheduling for opportunistic channel usage and exploiting MU diversity. We evaluate the benefits of the channel aware scheduling with respect to the produced overhead for signaling, channel estimation and channel quality Information (CQI) feedback.