Active antennas for MIMO and beamforming operation

Data rates in mobile communication networks are increasing dramatically by excessive usage of data traffic and thus driving the tendency for use of adaptive antennas (AAS) for MIMO operation (Multiple Input Multiple Output) and beam forming, procedures for coordinated multipoint transmission (COMP) and tendency to smaller cells. The acceptance of active antennas is very sensitive to the high reliability requirements. Thus the evolution goes step by step from the use of tower top Remote Radio Heads (RRH) to the integration of these radios into antennas and as a logical last step to the distributed transceivers in the antennas (Active Antenna Systems-AAS). These array antennas can be used in different operation modes: Beam forming, Polarization control and MIMO. This paper gives an overview about the actual status of radio integration and typical values for MIMO operation and evaluates the impact of vertical and horizontal steerable AAS on data throughput.