A Scalable Multi-User Uplink for Wi-Fi

Mobile devices have fewer antennas than APs due to size and energy constraints. This antenna asymmetry restricts uplink capacity to the client antenna array size rather than the AP’s. To overcome antenna asymmetry, multiple clients can be grouped into a simultaneous multiuser transmission to achieve a full rank transmission that matches the number of antennas at the AP. In this paper, we design, implement, and experimentally evaluate MUSE, the first distributed and scalable system to achieve full-rank uplink multi-user capacity without control signaling for channel estimation, channel reporting, or user selection. Our experiments demonstrate full-rank multiplexing gains in the evaluated scenarios that show linear gains as the number of users increase while maintaining constant overhead.