Apple Inc.
Efficient beam search methods for three-dimensional beamforming with non-precoded reference signals

Abstract:

A method and apparatus for three-dimensional beamforming, which include an estimation of a channel spatial coherence for a beam space of a device based on a plurality of non-precoded reference signals such that the beam space includes a plurality of beam subspaces based on the estimated channel spatial coherence and each of the plurality of beam subspaces include a beam direction representative of a respective beam subspace of the plurality of beam subspaces. Furthermore, a selection a beam subspace of the plurality of beam subspaces based on a channel quality metric of the beam direction that is representative of the beam subspace is included.