A System-Performance-Based Comparison of Sparse Regular and Irregular Antenna Arrays for Millimeter-Wave Multi-User MIMO Base Stations

A system-level study was conducted that evaluated the system performance of various dense and sparse antenna array configurations for application in millimeter-wave multi-user multiple-input multiple-output base stations. The performance was evaluated by investigating the probability that a user experiences an outage when a zero-forcing pre-coder is used in a random line of sight scenario. This paper shows that the outage probability significantly decreased when irregular sparse arrays were used rather than regular sparse or regular dense arrays. A re-configurable linear array was designed and realized as a demonstrator. It used 3D-printed aluminum box horn antenna elements that had wide scanning range in the azimuthal plane and a small scanning range in the elevation plane. For the demonstrator, it was shown that the outage probability was reduced from 3.85% to 0.64% by moving from a sparse regularly spaced array to a sparse randomly spaced array. This amounted to an improvement of a factor of six. The sparse topology allowed for the usage of large antenna elements that had an increased gain and still achieved wide-angle scanning, while reducing mutual coupling to a minimum

Sparse Array Topologies for 5G mmWave Base-Stations: A System-Level Study

A system-level study is conducted that evaluates the performance of various sparse array topologies for application in 5G base-stations. The performance metric is the probability a user experiences an outage, when applying a Zero-Forcing precoder in a Line-of-Sight scenario. The outage probability is shown to significantly decrease for sparse irregular arrays as compared to sparse regular and dense regular arrays. A re-configurable sparse array design at 28.5GHz is realized as a demonstrator