A Real-time 802.11 Compatible Distributed MIMO System

We present a demonstration of a real-time distributed MIMO system, DMIMO. DMIMO synchronizes transmissions from 4 distributed MIMO transmitters in time, frequency and phase, and performs distributed multi-user beamforming to independent clients. DMIMO is built on top of a Zynq hardware platform integrated with an FMCOMMS2 RF front end. The platform implements a custom 802.11n compatible MIMO PHY layer which is augmented with a lightweight distributed synchronization engine. The demonstration shows the received constellation points, channels, and effective data throughput at each client. It also shows how these vary as a function of interference, the timeliness of channel feedback, and the transmission rates used by the different transmitters.