Scaling Uplink Throughput in WLANs
Flores Miranda, Adriana B.
Knightly, Edward W.
Doctor of Philosophy
Form factor constraints often limit mobile clients to a single antenna, resulting in mobile devices having fewer antennas than Access Points (APs). This antenna asymmetry restricts uplink throughput to the client antenna array size rather than the AP’s. Antenna asymmetry can subsequently limit spatial multiplexing gains for transmissions between the client and AP. In this thesis, I design, implement and experimentally evaluate two standard compliant solutions that enable multiplexing gains in uplink transmissions for both single-user and multi-user paradigms. I first introduce 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. Second, I design, implement, and experimentally evaluate Chameleon, the first system to enable uplink spatial multiplexing for a single-user with a single antenna. In Chameleon, clients spoof an unmodified AP to infer that the single-antenna client has an array and spatial multiplexing capabilities. My experiments demonstrate full-rank multiplexing gains are achieved in both single-user and multi-user paradigms. The results show performance scaling, as the system gains increase with the number spatial streams, while I still maintain standard compatibility.