A Platform for At-Scale Wideband UHF MU-MIMO Systems

We present a Multi-User MIMO (MU-MIMO) array utilizing the Wideband UHF Radio daughter-Card (WURC), a new open platform for at-scale MU-MIMO transmissions in the UHF band up to 1 Watt over up to 28 MHz of programmable channel bandwidth. Using this platform, we demonstrate an application that measures and displays wideband MU-MIMO channel estimates and capacity for both UHF and 2.4 GHz WiFi channels, then performs beam-formed transmissions in realtime. This four-radio implementation has an upper limit of 10.8 b/s/Hz spectral efficiency up to 216 Mbps. An array of WURC analog front-ends coupled with WARP Software-Defined Radios (SDRs) is, to the best of our knowledge, the first open UHF MU-MIMO research platform that allows for integrated high-power transmission and at-scale topologies and experiments.