MUTE: Sounding inhibition for MU-MIMO WLANs

QoS-based Joint User Selection and Scheduling for MU-MIMO WLANs

“…Hence, the frequency of CSI requests should be optimized. The authors in [13] and [14] have shown the impact of the channel sounding interval on the performance of the system. The key objective of the papers discussed above is to reduce the CSI feedback overhead with the increase in the number of users.…”

“…In 802.11ac each user is selected randomly [6] with equal probability and requires M CSI feedbacks. Most publications have considered sounding all users before the transmission, whereas in [14] the author provided the flexibility to choose the subset of users that were sounded most recently. This exploited another direction and recently in [17] the author coupled the sounding, selecting and scheduling of users to maintain throughput and fairness performance.…”

“…For comparison purposes, we considered some well-known algorithms, namely 802.11ac, SUS with different α values [14] and the recent 802.11ac+ [16]. All simulations are performed using Matlab.…”

Combating inter-cell interference in 802.11ac-based multi-user MIMO networks

“…First, reporting the beamformed channel Hi→jvj instead of the physical channel Hi→j can proportionally reduce the size of the BF-R frame which is known to incur substantial overhead [5,21] to the channel sounding process of 802.11ac. This is because the beamformed channel is a vector while the physical channel is a matrix that needs many more bits to encode when the client has multiple antennas.…”

“…We calculate the network capacity based on the measured signal-to-noise-and-interference ratio (SINR) at each served client. While the actual throughput gain by MU-MIMO is known to be reduced by the channel sounding overhead [5,21], we do not incorporate such overhead into our evaluation since it equally exists in 802.11ac according to Section 6.1.…”