In WLANs, network-wide time and frequency synchronization among user devices is often considered essential for uplink MU-MIMO. Achieving such synchronization, however, incurs significant airtime overhead, compromising the throughput gains of MU-MIMO. In this demo, we demonstrate that time and frequency synchronization among user devices is not necessary for uplink MU-MIMO in WLANs. We developed a practical uplink MU-MIMO scheme that operates without requiring timing and clock frequency alignment among user devices. The key component of our solution is a new PHY design for the access point’s receiver, enabling it to decode concurrent signals from multiple asynchronous user devices. Experimental results indicate that uplink MU-MIMO is feasible in asynchronous wireless networks.

Key features of this project include: (i) no across-system coordination is needed for spectrum sharing, (ii) no inter-system synchronization is needed for spectrum sharing, and (iii) no central controller is needed for spectrum sharing.

Page modified 2025-07-03 13:43:08 EDT, by Huacheng Zeng.