Chorus: Truly distributed distributed-MIMO

Abstract

Distributed MIMO has long been known theoretically to bring large throughput gains to wireless networks. Recent years have seen significant interest and progress in developing practical distributed MIMO systems. However, these systems only distribute the transmission function across the multiple nodes. The control fabric that synchronizes the nodes to a common reference phase still fundamentally requires a single leader that all nodes in the network are capable of hearing. This paper presents Chorus, a truly distributed distributed-MIMO system. Chorus is leaderless - all nodes are peers, and jointly transmit the synchronization signal used by other nodes to synchronize to a common reference phase. The participation of all nodes in the network in the synchronization signal enables Chorus to scale to large networks, while being resilient to node failures or changes in network connectivity, and without imposing onerous management burdens on network administrators. We implement and evaluate Chorus and demonstrate that it can synchronize effectively without the need for a single leader, scale to large networks where no leader node can be heard by all others, and provide 2.7× throughput improvement over traditional leader-based systems.