Beam selection discovery window monitoring
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may perform cell discovery in a window by monitoring for and receiving synchronization signal blocks (SSBs) from a network entity. The UE may receive an indication of a numerical quantity of beams in a set of beams associated with SSB transmission during a discovery window. The UE may map a set of SSB transmissions within the discovery window to a set of SSB candidates within the discovery window using the receive indication of the numerical quantity of beams. The UE may select, for each SSB candidate of the set of SSB candidates, a beam from the set of beams for monitoring each SSB candidate. The UE may monitor the SSB candidates in accordance with the beam selected for each SSB candidate. The UE may then receive one or more SSBs in accordance with the monitoring.
1. A method for wireless communication at a user equipment (UE), comprising:
determining a numerical quantity of beams in a set of beams associated with synchronization signal block transmissions during a discovery window, wherein the numerical quantity is less than a maximum number of beams supported by a network entity;
mapping a plurality of synchronization signal block transmissions within the discovery window to a plurality of synchronization signal block candidates within the discovery window using the numerical quantity of beams, wherein the plurality of synchronization signal block candidates is a subset of a total number of synchronization signal block candidates within the discovery window;
selecting, for each synchronization signal block candidate of the plurality of synchronization signal block candidates associated with the discovery window, a respective beam from the set of beams for monitoring each synchronization signal block candidate, wherein the respective beam is selected as a function of an index of a corresponding synchronization signal block candidate and the numerical quantity of beams, wherein at least a first beam from the set of beams is associated with two or more synchronization signal block candidates;
monitoring the plurality of synchronization signal block candidates in accordance with the respective beam selected for each synchronization signal block candidate; and
receiving one or more synchronization signal blocks in accordance with the monitoring, wherein a single synchronization signal block is received via one of the two or more synchronization signal block candidates associated with the first beam.
2. The method of claim 1 , wherein determining the numerical quantity of beams comprises:
receiving an express value of the numerical quantity of beams.
3. The method of claim 1 , wherein determining the numerical quantity of beams comprises:
receiving a numerical value of sub-windows of the discovery window, each sub-window being associated with at least one synchronization signal block transmission over each beam of the set of beams, wherein the numerical quantity of beams is implicit in the numerical value of sub-windows.
4. The method of claim 3 , further comprising:
receiving a repetition parameter indicating a number of times each beam in the set of beams is repeated within each sub-window of the discovery window.
5. The method of claim 4 , wherein mapping the plurality of synchronization signal block transmissions to the plurality of synchronization signal block candidates is a further function of the repetition parameter.
6. The method of claim 4 , wherein each beam is repeated over consecutive synchronization signal block candidates of the plurality of synchronization signal block candidates within a given sub-window of the discovery window.
7. The method of claim 4 , further comprising:
transmitting one or more of: a request for the repetition parameter or a UE capability to support the repetition parameter, wherein the repetition parameter is received responsive to the request for the repetition parameter or the UE capability to support the repetition parameter.
8. The method of claim 1 , wherein monitoring the plurality of synchronization signal block candidates in accordance with the beam selected for each synchronization signal block candidate comprises:
combining multiple synchronization signal block candidates within the discovery window, wherein the plurality of synchronization signal block candidates are associated with a single beam of the set of beams.
9. The method of claim 1 , wherein monitoring the plurality of synchronization signal block candidates in accordance with the beam selected for each synchronization signal block candidate comprises:
discarding one of multiple synchronization signal block candidates within the discovery window, wherein the plurality of synchronization signal block candidates are associated with a single beam of the set of beams.
10. The method of claim 1 , wherein determining the numerical quantity of beams comprises:
receiving a master information block comprising an indication of the numerical quantity of beams.
11. The method of claim 10 , wherein the numerical quantity of beams is signaled by at least one bit in a subcarrier spacing common field and at least one unused bit of the master information block.
12. The method of claim 1 , wherein the numerical quantity of beams in the set of beams corresponds to the synchronization signal block transmissions during the discovery window in a licensed radio frequency spectrum band.
13. The method of claim 1 , further comprising:
transmitting one or more of: a request for the numerical quantity of beams or a UE capability to support the numerical quantity of beams, wherein an indication of the numerical quantity of beams is received responsive to the request for the numerical quantity of beams or the UE capability to support the numerical quantity of beams.
14. A method for wireless communication at a network entity, comprising:
transmitting an indication of a numerical quantity of beams in a set of beams associated with synchronization signal block transmissions during a discovery window in a licensed radio frequency spectrum band, wherein the numerical quantity is less than a maximum number of beams supported by the network entity, wherein at least a first beam from the set of beams is associated with two or more synchronization signal block candidates; and
transmitting one or more synchronization signal blocks in accordance with the indication, wherein a single synchronization signal block is transmitted via one of the two or more synchronization signal block candidates associated with the first beam.
15. The method of claim 14 , wherein transmitting the indication of the numerical quantity of beams comprises:
transmitting an express value of the numerical quantity of beams.
16. The method of claim 14 , wherein transmitting the indication of the numerical quantity of beams comprises:
transmitting a numerical value of sub-windows of the discovery window, each sub-window being associated with at least one synchronization signal block transmission over each beam of the set of beams, wherein the numerical quantity of beams is implicit in the numerical value of sub-windows.
17. The method of claim 16 , further comprising:
transmitting a repetition parameter indicating a number of times each beam in the set of beams is repeated within each sub-window of the discovery window.
18. The method of claim 17 , wherein each beam is repeated over consecutive synchronization signal block candidates of a plurality of synchronization signal block candidates within a given sub-window of the discovery window.
19. The method of claim 17 , further comprising:
receiving a request for the repetition parameter; and
transmitting the repetition parameter responsive to the request for the repetition parameter.
20. The method of claim 17 , further comprising:
receiving a user equipment (UE) capability to support the repetition parameter; and
transmitting the repetition parameter responsive to the UE capability to support the repetition parameter.
21. The method of claim 14 , wherein transmitting the indication of the numerical quantity of beams comprises:
transmitting one or more of: a master information block comprising the indication of the numerical quantity of beams, a system information block comprising the indication of the numerical quantity of beams, a radio resource control message comprising the indication of the numerical quantity of beams, or a physical broadcast channel transmission comprising the indication of the numerical quantity of beams.
22. The method of claim 21 , further comprising:
transmitting the master information block comprising a subcarrier spacing common field comprising the indication of the numerical quantity of beams.
23. The method of claim 21 , further comprising:
performing a physical layer multiplexing of the physical broadcast channel transmission; and
transmitting the indication of the numerical quantity of beams in the physical broadcast channel transmission.
24. The method of claim 14 , further comprising:
receiving a request for the numerical quantity of beams; and
transmitting the indication of the numerical quantity of beams responsive to the request for the numerical quantity of beams.
25. The method of claim 14 , further comprising:
receiving a UE capability to support the numerical quantity of beams; and
transmitting the indication of the numerical quantity of beams responsive to the UE capability to support the numerical quantity of beams.
26. An apparatus for wireless communication at a user equipment (UE), comprising:
a processor; and
a memory coupled with the processor, wherein the memory includes instructions executable by the processor to cause the apparatus to:
determine a numerical quantity of beams in a set of beams associated with synchronization signal block transmissions during a discovery window, wherein the numerical quantity is less than a maximum number of beams supported by a network entity;
map a plurality of synchronization signal block transmissions within the discovery window to a plurality of synchronization signal block candidates within the discovery window using the numerical quantity of beams, wherein the plurality of synchronization signal block candidates is a subset of a total number of synchronization signal block candidates within the discovery window;
select, for each synchronization signal block candidate of the plurality of synchronization signal block candidates associated with the discovery window, a respective beam from the set of beams for monitoring each synchronization signal block candidate, wherein the respective beam is selected as a function of an index of a corresponding synchronization signal block candidate and the numerical quantity of beams, wherein at least a first beam from the set of beams is associated with two or more synchronization signal block candidates;
monitor the plurality of synchronization signal block candidates in accordance with the respective beam selected for each synchronization signal block candidate; and
receive one or more synchronization signal blocks in accordance with a monitoring of the plurality of synchronization signal block candidates, wherein a single synchronization signal block is received via one of the two or more synchronization signal block candidates associated with the first beam.
27. The apparatus of claim 26 , wherein the instructions to determine the numerical quantity of beams are executable by the processor to cause the apparatus to:
receive an express value of the numerical quantity of beams.
28. The apparatus of claim 26 , wherein the instructions to determine the numerical quantity of beams are executable by the processor to cause the apparatus to:
receive a numerical value of sub-windows of the discovery window, each sub-window being associated with at least one synchronization signal block transmission over each beam of the set of beams, wherein the numerical quantity of beams is implicit in the numerical value of sub-windows.
29. An apparatus for wireless communication at a network entity, comprising:
a processor; and
a memory coupled with the processor, wherein the memory includes instructions executable by the processor to cause the apparatus to:
transmit an indication of a numerical quantity of beams in a set of beams associated with synchronization signal block transmissions during a discovery window in a licensed radio frequency spectrum band, wherein the numerical quantity is less than a maximum number of beams supported by the network entity, wherein at least a first beam from the set of beams is associated with two or more synchronization signal block candidates; and
transmit one or more synchronization signal blocks in accordance with the indication, wherein a single synchronization signal block is transmitted via one of the two or more synchronization signal block candidates associated with the first beam.
30. The apparatus of claim 29 , wherein the instructions to transmit the indication of the numerical quantity of beams are executable by the processor to cause the apparatus to:
transmit an express value of the numerical quantity of beams.