Reconfigurable intelligent surface or repeater assisted synchronization signal block transmission and initial access
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a synchronization signal block (SSB) transmitted by a base station. The UE may receive system information that includes reconfigurable intelligent surface (RIS) or repeater assisted initial access information that identifies a set of SSBs that are associated with an RIS or a repeater and a modulation signature associated with the RIS or the repeater. The UE may selectively perform initial access using the SSB or search for another SSB based at least in part on the RIS or repeater assisted initial access information. Numerous other aspects are described.
1. A user equipment (UE) for wireless communication, the UE comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, configured to:
receive information identifying a set of synchronization signal blocks (SSBs) that are associated with a reconfigurable intelligent surface (RIS) or a repeater, the information identifying a modulation signature associated with the RIS or the repeater; and
select between performing initial access using an SSB and searching for another SSB based at least in part on the information.
2. The UE of claim 1 , wherein the one or more processors are further configured to:
detect whether the SSB is modulated with the modulation signature associated with the RIS or the repeater.
3. The UE of claim 2 , wherein the one or more processors are further configured to:
perform initial access using the SSB based at least in part on detecting that the SSB is modulated with the modulation signature associated with the RIS or the repeater; or
search for another SSB to use to perform initial access based at least in part on detecting that the SSB is not modulated with the modulation signature associated with the RIS or the repeater.
4. The UE of claim 1 , wherein the one or more processors are further configured to:
perform RIS-assisted initial access using the SSB based at least in part on detecting that the SSB is modulated with the modulation signature associated with the RIS or the repeater.
5. The UE of claim 1 , wherein the modulation signature associated with the RIS or the repeater modulates at least one of a phase, an amplitude, a frequency, or a polarization at symbol boundaries of a signal redirected from the RIS or the repeater.
6. The UE of claim 1 , wherein the information indicates respective SSB indices for one or more SSBs in the set of SSBs that are associated with the RIS or the repeater.
7. The UE of claim 1 , wherein the one or more processors are further configured to:
perform initial access using the SSB based at least in part on a determination that the SSB is not included in the set of SSBs associated with the RIS or the repeater.
8. The UE of claim 1 , wherein the information is initial access information that is RIS assisted initial access information or repeater assisted initial access information.
9. The UE of claim 1 , wherein the one or more processors are further configured to:
receive, from a network entity, the SSB, wherein selecting between performing initial access using the SSB and searching for another SSB is based at least in part on receiving the SSB.
10. A network entity for wireless communication, the network entity comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, configured to:
transmit a synchronization signal block (SSB) burst set including a first set of SSBs and a second set of SSBs; and
transmit information identifying the second set of SSBs as being associated with a reconfigurable intelligent surface (RIS) or a repeater, the information identifying a modulation signature associated with the RIS or the repeater.
11. The network entity of claim 10 , wherein the modulation signature associated with the RIS or the repeater modulates at least one of a phase, an amplitude, a frequency, or a polarization at symbol boundaries of a signal redirected from the RIS or the repeater.
12. The network entity of claim 10 , wherein the one or more processors, to transmit the SSB burst set, are configured to:
transmit the second set of SSBs toward the RIS or the repeater, wherein each SSB in the second set of SSBs is to be modulated by the RIS or the repeater by the modulation signature associated with the RIS or the repeater.
13. The network entity of claim 10 , wherein the one or more processors are further configured to:
control the RIS or the repeater to modulate each SSB in the second set of SSBs by the modulation signature associated with the RIS or the repeater.
14. The network entity of claim 10 , wherein the one or more processors, to transmit the SSB burst set, are further configured to:
transmit an SSB in the first set of SSBs on a first beam toward the RIS or the repeater or on a second beam that satisfies a distance threshold with respect to the first beam.
15. The network entity of claim 14 , wherein the one or more processors, to transmit the SSB in the first set of SSBs, are configured to transmit the SSB in the first set of SSBs at a second power that is higher than a first power for transmitting an SSB in the second set of SSBs.
16. The network entity of claim 15 , wherein the one or more processors, to transmit the SSB in the first set of SSBs, are configured to:
transmit the SSB in the first set of SSBs using an increased radiated power from each antenna element of one or more antenna elements of an antenna array of the network entity, as compared with a radiated power used for transmitting the SSB in the second set of SSBs.
17. The network entity of claim 15 , wherein the one or more processors, to transmit the SSB in the first set of SSBs, are configured to:
transmit the SSB in the first set of SSBs using an increased beamforming gain, as compared with a beamforming gain used for transmitting the SSB in the second set of SSBs.
18. The network entity of claim 10 , wherein the first set of SSBs is associated with direct transmission from the network entity.
19. The network entity of claim 10 , wherein the information is initial access information that is RIS assisted initial access information or repeater assisted initial access information.
20. A method of wireless communication performed by a user equipment (UE), the method comprising:
receiving information identifying a set of synchronization signal blocks (SSBs) that are associated with a reconfigurable intelligent surface (RIS) or a repeater, the information identifying a modulation signature associated with the RIS or the repeater; and
selecting between performing initial access using an SSB and searching for another SSB based at least in part on the information.
21. The method of claim 20 , further comprising:
detecting whether the SSB is modulated with the modulation signature associated with the RIS or the repeater.
22. The method of claim 21 , further comprising:
performing initial access using the SSB based at least in part on detecting that the SSB is modulated with the modulation signature associated with the RIS or the repeater; or
searching for another SSB to use to perform initial access based at least in part on detecting that the SSB is not modulated with the modulation signature associated with the RIS or the repeater.
23. The method of claim 20 , wherein the modulation signature associated with the RIS or the repeater modulates at least one of a phase, an amplitude, a frequency, or a polarization at symbol boundaries of a signal redirected from the RIS or the repeater.
24. The method of claim 20 , further comprising:
performing initial access using the SSB based at least in part on a determination that the SSB is not included in the set of SSBs associated with the RIS or the repeater.
25. A method of wireless communication performed by a network entity, the method comprising:
transmitting a synchronization signal block (SSB) burst set including a first set of SSBs and a second set of SSBs; and
transmitting information identifying the second set of SSBs as being associated with a reconfigurable intelligent surface (RIS) or a repeater, the information identifying a modulation signature associated with the RIS or the repeater.
26. The method of claim 25 , wherein the modulation signature associated with the RIS or the repeater modulates at least one of a phase, an amplitude, a frequency, or a polarization at symbol boundaries of a signal redirected from the RIS or the repeater.
27. The method of claim 25 , wherein transmitting the SSB burst set comprises:
transmitting the second set of SSBs toward the RIS or the repeater, wherein each SSB in the second set of SSBs is to be modulated by the RIS or the repeater by the modulation signature associated with the RIS or the repeater.
28. The method of claim 27 , further comprising:
controlling the RIS or the repeater to modulate each SSB in the second set of SSBs by the modulation signature associated with the RIS or the repeater.
29. The method of claim 27 , wherein transmitting the SSB burst set further comprises:
transmitting an SSB in the first set of SSBs on a first beam toward the RIS or the repeater or on a second beam that satisfies a distance threshold with respect to the first beam.
30. The method of claim 29 , wherein transmitting the SSB in the first set of SSBs comprises transmitting the SSB in the first set of SSBs at a second power that is higher than a first power for transmitting an SSB in the second set of SSBs.