Requesting a waveform change
Apparatuses, methods, and systems are disclosed for requesting a waveform change. One method includes receiving, at a user equipment, first information indicating configurations for a plurality of waveforms and an indication indicating that the user equipment is enabled to request a waveform change, a subcarrier spacing change, or a combination thereof. The method includes transmitting a request message to a base station. The request message requests the waveform change, the subcarrier spacing change, or the combination thereof. The method includes receiving a response message from the base station. The response message indicates whether the request for the waveform change, the subcarrier spacing change, or the combination thereof is approved.
1 . A method performed by user equipment (UE), the method comprising:
receiving first information indicating configuration for a plurality of waveforms and an indication indicating that the UE is enabled to request a waveform change;
receiving a system information block (SIB) random access channel (RACH) configuration comprising a mapping between a plurality of RACH preambles and the plurality of waveforms;
transmitting a request message to a base station, wherein the request message comprises a RACH preamble of the plurality of RACH preambles corresponding to a waveform of the plurality of waveforms from the mapping in the SIB RACH configuration and requests the waveform change; and
receiving a response message from the base station, wherein the response message indicates whether the request for the waveform change is approved.
2 . The method of claim 1 , further comprising receiving a plurality of RACH root sequence indexes, wherein each sequence index of the plurality of RACH root sequence indexes corresponds to a corresponding waveform of the plurality of waveforms.
3 . The method of claim 1 , further comprising receiving path loss information corresponding to one or more of a synchronization signal block (SSB) threshold, a reference signal received power threshold, a reference signal received quality threshold, or a signal to interference noise ratio threshold and triggering the request message based on the one or more of the synchronization signal block threshold, the reference signal received power threshold, the reference signal received quality threshold, or the signal to interference noise ratio threshold.
4 . The method of claim 1 , wherein the request message comprises the RACH preamble that belongs to a root sequence index or a preamble identifier group that corresponds to the waveform change.
5 . The method of claim 1 , wherein, in response to a two step RACH procedure being used, the request message comprises an explicit request using a physical uplink shared channel (PUSCH) message payload.
6 . The method of claim 1 , wherein the request message comprises an implicit request using a demodulation reference signal sequence of a physical uplink shared channel of message A.
7 . The method of claim 1 , wherein the response message is received as a random access response or a message B.
8 . The method of claim 1 , wherein the response message indicates a symbol offset or a slot offset for applying the waveform change.
9 . The method of claim 1 , wherein the response message indicates either that the request for the waveform change is approved or that a default waveform is to be used.
10 . A user equipment (UE), comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive first information indicating configurations for a plurality of waveforms and an indication indicating that the UE is enabled to request a waveform change;
receive a system information block (SIB) random access channel (RACH) configuration comprising a mapping between a plurality of RACH preambles and the plurality of waveforms;
transmit a request message to a base station, wherein the request message comprises a RACH preamble of the plurality of RACH preambles corresponding to a waveform of the plurality of waveforms from the mapping in the SIB RACH configuration and requests the waveform change; and
receive a response message from the base station, wherein the response message indicates whether the request for the waveform change is approved.
11 . A base station, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the base station to:
transmit first information indicating configurations for a plurality of waveforms and an indication indicating that a user equipment (UE) is enabled to request one or more of a waveform change;
transmit a system information block (SIB) random access channel (RACH) configuration comprising a mapping between a plurality of RACH preamble and the plurality of waveforms;
receive a request message from the UE, wherein the request message comprises a RACH preamble of the plurality of RACH preambles corresponding to a waveform of the plurality of waveforms from the mapping in the SIB RACH configuration and requests for the waveform change is approved.
12 . The base station of claim 11 , wherein the at least one processor is configured to cause the base station to transmit a plurality of RACH root sequence indexes, wherein each sequence index of the plurality of RACH root sequence indexes corresponds to a corresponding waveform of the plurality of waveforms.
13 . The base station of claim 11 , wherein the at least one processor is configured to cause the base station to transmit path loss information corresponding to a synchronization signal block (SSB) threshold, a reference signal received power threshold, a reference signal received quality threshold, or a signal to interference noise ratio threshold and triggering the request message based on the one or more of the synchronization signal block threshold, the reference signal received power threshold, the reference signal received quality threshold, or the signal to interference noise ratio threshold.
14 . The base station of claim 11 , wherein the request message comprises the RACH preamble that belongs to a root sequence index or a preamble identifier group that corresponds to the waveform change.
15 . The base station of claim 11 , wherein, in response to a two step RACH procedure being used, the request message comprises an explicit request using a physical uplink shared channel (PUSCH) message payload.
16 . The base station of claim 11 , wherein the request message comprises an implicit request using a demodulation reference signal sequence of a physical uplink shared channel of message A.
17 . A processor for wireless communication, comprising:
at least one controller coupled with at least one memory and configured to cause the processor to:
receive first information indicating configurations for a plurality of waveforms and an indication indicating that the processor is enabled to request a waveform;
receive a system information block (SIB) random access channel (RACH) configuration comprising a mapping between a plurality of RACH preambles and the plurality of waveforms;
transmit a request message to a base station, wherein the request message comprises a RACH preamble of the plurality of RACH preambles corresponding to a waveform of the plurality of waveforms from the mapping in the SIB RACH configuration and requests the waveform change; and
receive a response message from the base station, wherein the response message indicates whether the request for the waveform change is approved.
18 . The processor of claim 17 , wherein the at least one controller is configured to cause the processor to receive a plurality of RACH root sequence indexes, wherein each sequence index of the plurality of RACH root sequence indexes corresponds to a corresponding waveform of the plurality of waveforms.