In order to achieve seamless indoor coverage with data rates up to 10 Gbit per second targeted for 5G, Fraunhofer IIS has developed the concept of a Shared UE-side Distributed Antenna System (SUDAS). SUDAS is an infrastructure of many low-price and easy-to-implement relay nodes scattered in a building or a vehicle that receive signals from base stations and forward them in an mm-wave band. The signals are received by the user equipment (UE) in the building or vehicle.
SUDAS is a type of virtual MIMO (multiple input multiple output) scheme. More specifically, it is a UE-side coordinated multipoint (UE-CoMP) scheme that translates massive spatial multiplexing in a licensed mobile band into massive frequency multiplexing in an unlicensed mm-wave band or vice versa.