Device and method for synchronous beam switching
Devices for and methods of synchronous beam refinement using a beam refinement reference signal (BRRS) are generally described. In one example embodiment, a UE receives BRRS information indicating switching of a Tx beam. The UE then uses this information to switch an associated Rx beam. In some embodiments, timing information is used to match the switching times. In some embodiments. DCI and CSI-RS operations are used to determine switching for the synchronous beam refinement.
1. An apparatus of a user equipment (UE), the apparatus comprising:
a memory; and
processing circuitry in communication with the memory and arranged to:
decode a downlink control information (DCI) received in a physical downlink control channel (PDCCH) from a base station that includes an indication that a transmission (Tx) beam is to switch to an updated Tx beam;
wherein in response to the DCI, the processing circuitry is to initiate switching from a receive (Rx) beam to an updated Rx beam to match the updated Tx beam; and
receive a data transmission associated with the updated Tx beam using the updated Rx beam.
2. The apparatus of claim 1 , wherein the processing circuitry initiates switching from the Rx beam to the updated Rx beam to match the updated Tx beam at a non-zero time offset relative to receiving the DCI.
3. The apparatus of claim 1 , wherein the indication comprises a beam refinement reference signal (BRRS) format indicator within the DCI.
4. The apparatus of claim 3 , wherein said switching from the RX beam to the updated Rx beam to match the updated Tx beam is performed based on identifying that the BRRS format indicator indicates abrupt beam switching.
5. The apparatus of claim 1 , wherein the processing circuitry is further configured to:
receive a channel state information reference signal (CSI-RS) on the updated TX beam prior to receiving the data transmission.
6. The apparatus of claim 5 , wherein said switching from the RX beam to the updated Rx beam to match the updated Tx beam is based on measurements of the CSI-RS.
7. The apparatus of claim 1 , wherein the processing circuitry is further configured to select the updated Rx beam from a set of candidate Rx beams.
8. A base station, comprising:
a radio;
a memory; and
processing circuitry in communication with the memory and the radio and arranged to:
transmit a downlink control information (DCI) received in a physical downlink control channel (PDCCH) to a user equipment (UE) device that includes an indication that a transmission (Tx) beam is to switch to an updated Tx beam;
wherein the DCI indicates for the UE to initiate switching from a receive (Rx) beam to an updated Rx beam to match the updated Tx beam; and
transmit a data transmission associated with the updated Tx beam.
9. The base station of claim 8 , wherein the DCI indicates for the UE to initiate said switching from Rx beam to the updated Rx beam to match the updated Tx beam at a non-zero time offset relative to the UE receiving the DCI.
10. The base station of claim 9 , wherein the indication comprises a beam refinement reference signal (BRRS) format indicator within the DCI.
11. The base station of claim 10 , wherein said switching from the RX beam to the updated Rx beam to match the updated Tx beam is based on identifying that the BRRS format indicator indicates abrupt beam switching.
12. The base station of claim 8 , wherein the processing circuitry is further configured to:
transmit a channel state information reference signal (CSI-RS) on the updated TX beam prior to transmitting the data transmission.
13. The base station of claim 12 , wherein said switching from the RX beam to the updated Rx beam to match the updated Tx beam is performed based on measurements of the CSI-RS.
14. The base station of claim 13 , wherein the processing circuitry is further configured to transmit radio resource control (RRC) signaling to the UE to configure the updated TX beam for the CSI-RS.
15. A method for operating a user equipment (UE) device, the method comprising:
decoding a downlink control information (DCI) in a physical downlink control channel (PDCCH) received from a base station that includes an indication that a transmission (Tx) beam is to switch to an updated Tx beam;
in response to the DCI, initiating switching from a receive (Rx) beam to an updated Rx beam to match the updated Tx beam; and
receiving a data transmission associated with the updated Tx beam using the updated Rx beam.
16. The method of claim 15 ,
wherein initiating switching from the Rx beam to the updated Rx beam to match the updated Tx beam is performed at a non-zero time offset relative to receiving the DCI.
17. The method of claim 15 ,
wherein the indication is a beam refinement reference signal (BRRS) format indicator within the DCI, and
wherein said switching from the RX beam to the updated Rx beam to match the updated Tx beam is performed based on identifying that the BRRS format indicator indicates abrupt beam switching.
18. The method of claim 15 , the method further comprising:
receiving a channel state information reference signal (CSI-RS) on the updated TX beam prior to receiving the data transmission.
19. The method of claim 18 , wherein said switching from the RX beam to the updated Rx beam to match the updated Tx beam is performed based on measurements of the CSI-RS.
20. The method of claim 19 , the method further comprising receiving radio resource control (RRC) signaling to configure the updated TX beam for the CSI-RS.