Millimeter-wave MIMO : Wireless Links at Optical Speeds

We propose a new architecture for bridging the existing gap in speeds between wireless and optical links. T he Millimeter Wave MIMO system employs “millimeter (mm) wave” spectrum in the E-band (70-95 GHz), which has been made available by the Federal Communications Commission on a semi-unlicensed basis for outdoor point-to-point communi cation. The small wavelengths enable highly directive beams providing link budgets sufficient to communicate even in poor weather conditions over ranges of the order of kilometers, while requiring radio frequency (RF) front-ends that can be realized in low-cost silicon processes. Furthermore, because of the small wavelengths, spatial multiplexing gains can be obtained evn in Line of Sight (LOS) environments with only a moderate separation of transmitters. The proposed mm-wave MultipleInput Multiple-Output system exploits these characteristics to provide LOS links of speeds of up to 40 Gbps (e.g., by supporting eight 5 Gbps links in parallel between two nodes) . This paper provides an initial exposition of the key concept s, provides some rough calculations of attainable performanc e, and hints at the issues that must be addressed before this concept can become a reality.