Demonstrating 139 Gbps and 55.6 bps/Hz Spectrum Efficiency Using 8×8 MIMO over a 1.5-km Link at 73.5 GHz

Wireless backhaul using line-of-sight MIMO (LOS-MIMO) has the potential to support the increased data-rate demands brought by the introduction of the fifth generation of mobile access technology. In this paper, we present results from an outdoor 1.5-km link using eight LOS-MIMO streams in a single channel. The link operated at E-band (70/80 GHz) using commercial radios and unsynchronized oscillators. An aggregated throughput of 139 Gbps was achieved with a 99.965% availability, resulting in a spectrum efficiency of 55.6 bps/Hz. Moreover, the robustness of the link at suboptimal deployments was verified, agreeing well with the theoretically expected results. Such microwave links are of great importance for future generation mobile broadband networks, providing a cost-effective alternative to fiber backhaul.