Patent ID: 9414371
Filing Date: 2016-08-09
CPC Classification: H04B,H04L,H04W

Claim Text:
1. A method, comprising: configuring, by a base station (BS), hierarchical channel sounding, each using a different transmitter spatial processing scheme, wherein the hierarchical channel sounding comprises synchronization signals, sector-level reference signals, and slice-level reference signals; establishing, by the BS, the hierarchical channel sounding associated with the different transmitter spatial processing scheme to at least one mobile station (MS) over a massive multi-input multi-output (MIMO) channel, wherein the different transmitter spatial processing scheme is determined by a different set of multiple angle of departures, and a different set of transmitter codebooks or a different set of transmitter precoders; receiving, by the BS, a feedback signal from the at least one MS over the massive MIMO channel, wherein the feedback signal includes at least one preferred slice information associated with the slice-level reference signals that have been transmitted to the MS; determining, by the BS, an actual slice in accordance with the feedback information, long-term channel state information (CSI) received from the at least one MS, and short-term CSI received from the at least one MS, wherein the long-term CSI is determined by the synchronization signals and the sector-level reference signals, and the short-term CSI is determined by the slice-level reference signals included in the hierarchical channel sounding; and transmitting one or more reference signals associated with the determined actual slice to the at least one MS, wherein the actual slice is an active slice providing a communication between the at least one MS and the BS, and wherein the reference signals associated with the determined actual slice are slice-level reference signals.