CPC H04W 88/10 (2013.01) [H04B 7/0456 (2013.01); H04L 5/0051 (2013.01); H04L 5/10 (2013.01); H04L 25/0226 (2013.01); H04W 4/80 (2018.02)] | 19 Claims |
1. A user equipment (UE) comprising:
at least one communication processor;
at least one radio frequency integrated circuit (RFIC) configured to convert data transmitted from the at least one communication processor into at least one radio frequency (RF) signal and output the at least one RF signal; and
at least one antenna configured to receive each of the at least one RF signal and radiate an electromagnetic field,
wherein the at least one communication processor is configured to:
receive, from a base station, a downlink channel state information reference signal (DL CSI-RS) for identifying a state of a downlink channel between the UE and the base station through the at least one antenna and the at least one RFIC,
using reciprocity information between the downlink channel and an uplink channel between the UE and the base station, identify information about the uplink channel, based on the DL CSI-RS received from the base station,
based on the information about the identified uplink channel, identify a precoder for the identified uplink channel from a subset of precoders,
based on the identified precoder, precode uplink data and a demodulation reference signal (DMRS),
transmit a signal based on the precoded data to the base station using at least some of the at least one RFIC and the at least one antenna,
identify whether a configured condition is satisfied based on whether an interval between a reception time of the DL CSI-RS and a transmission time of the uplink data exceeds a specified threshold time, and
based on identifying that the configured condition is satisfied, perform the identification of the uplink channel and the identification of the precoder.
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