Using queue statistics in beamforming for ALOHA

We address the problem of receiver design for the uplink of a WLAN network from a stability viewpoint. We propose a cross layer approach that incorporates the users´ buffer statistics for the design of smart antennas employed by the base station/access point. In particular, we consider slotted ALOHA as the MAC protocol and we propose a linear MMSE front-end that utilizes the probability of a users´ queue being empty in its design. We compare the performance of the proposed MMSE front-end with the best adaptive front-end for the two user case and show that under certain conditions the proposed front-end is close to optimal.