Channel capacity analysis of different mobile antenna array topologies in the outdoor urban environment for 5G mm wave system

The 15 and 28 GHz frequency bands have been identified as interesting candidates for future 5G cellular communication systems. In this paper, based on ray-tracing simulations, we investigate the channel capacities at 15 and 28 GHz for a number of different array processing techniques, including beamforming, spatial multiplexing, and two types of hybrid beamforming. This is done for an 8×32 multiple input multiple output system, for the single user case. The hybrid beamforming techniques combines the beamforming and spatial multiplexing techniques, in order to reduce the number of analog-to-digital converters and thereby reducing the system complexity, while still maintaining multiplexing capabilities for improved system capacities. The achieved channel capacities the hybrid beamforming techniques with up to four parallel streams outperforms pure beamforming, but does not reach capacities close to that of full spatial multiplexing. This indicates that the outdoor channel can support multiplexing of more than four parallel data streams to a single user.