LAUSR

In this article, the evolution of two core multiple-input multiple-output (MIMO) features of the 5G New Radio standardization is described along with their motivations, salient designs, and demonstrated benefits. The first feature enables high spectral efficiency with reduced overhead and complexity in the sub-6 GHz regime by exploiting frequency-domain compression and angle-delay reciprocity inherent in high-resolution precoding codebooks for multi-user MIMO. The second feature, intended for the over-6 GHz regime, facilitates streamlined beam management with greatly reduced signaling overhead and latency as well as improved link reliability in the presence of challenging scenarios such as high mobile speed, large number of analog beams, and unpre-dictable signal blocking. The presented features are the outcome of a five-year work and expected to continue evolving to meet a growing number of challenges from new deployment scenarios.