Beamspace MIMO Channel Modeling and Measurement: Methodology and Results at 28GHz

Abstract

Millimeter-wave (mmW) wireless is as a promising technology for meeting the Gigabit rate and millisecond latency requirements of emerging 5G applications. This promise fundamentally rests on the large (GHz) bandwidths and high-gain/high- dimensional beamforming possible at mmW frequencies. While multi-beam operation is necessary for achieving spatial multiplexing, existing channel measurements are limited to mechanically pointed horn antennas and single- beam phased arrays of moderate sizes. In this paper, we report a new measurement methodology and initial results based on the concept of beamspace MIMO channel modeling and communication. The measurement results use a novel multi-beam MIMO prototype system at 28GHz that uses a lens array for analog beamforming with a beamwidth of about four degrees. Furthermore, it is the first mmW MIMO prototype that enables simultaneous multi-beam channel measurements (and communication). The unique measurement capabilities of the multi- beam MIMO prototype are discussed and the new modeling methodology is illustrated with initial indoor measurements.