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 from a network node that includes an indication of transmitter (TX) beam switching;
in response to the DCI, receive signals from the network node using an updated receive (Rx) beam corresponding to an updated TX beam, instead of a first Rx beam, after application of a time offset for application of beam switching.
2. The apparatus of claim 1 ,
wherein the time offset is applied 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 receiving signals from the network node using the updated Rx beam instead of the first Rx 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 signals from the network node.
6. The apparatus of claim 5 , wherein said receiving signals from the network node using the updated Rx beam instead of the first Rx beam is performed 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 network node, 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) to the UE that includes an indication of transmitter (TX) beam switching, wherein the DCI indicates for the UE to receive signals from the network node using an updated receive (Rx) beam corresponding to an updated TX beam, instead of a first Rx beam, after application of a time offset for application of beam switching; and
transmit signals associated with the updated Tx beam.
9. The network node of claim 8 , wherein the time offset is applied relative to receiving the DCI.
10. The network node of claim 9 , wherein the indication comprises a beam refinement reference signal (BRRS) format indicator within the DCI.
11. The network node of claim 10 , wherein the DCI indicates for the UE to receive signals from the network node using the updated Rx beam corresponding to the updated TX beam based on identifying that the BRRS format indicator indicates abrupt beam switching.
12. The network node 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 signals.
13. The network node of claim 12 , wherein the DCI indicates for the UE to receive signals from the network node using the updated Rx beam corresponding to the updated TX beam based on measurements of the CSI-RS.
14. The network node of claim 13 , wherein the RRC signaling configures 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) received from a network node that includes an indication of transmitter (TX) beam switching;
in response to the DCI, receiving signals from the network node using an updated receive (Rx) beam corresponding to an updated TX beam, instead of a first Rx beam, after application of a time offset for application of beam switching.
16. The method of claim 15 ,
wherein the time offset is applied relative to receiving the DCI.
17. The method of claim 15 ,
wherein said receiving signals from the network node using the updated Rx beam instead of the first Rx beam is performed based on identifying that the indication 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 signals from the network node.
19. The method of claim 18 , wherein said receiving signals from the network node using the updated Rx beam instead of the first Rx beam is performed based on measurements of the CSI-RS.
20. The method of claim 19 , wherein the RRC signaling configures the updated TX beam for the CSI-RS.