Methods and apparatuses for uplink power control for small data transmission when in a non-connected state

Patent metadata

Field	Value
Publication number	US-2024155502-A1
Application number	US-202218280982-A
Country	US
Kind code	A1
Filing date	Mar 22, 2022
Priority date	Mar 24, 2021
Publication date	May 9, 2024
Grant date	—

Abstract

The present disclosure is related to power control for small data transmission (SDT). The method at a user equipment (UE) for controlling transmission power for configured grant (CG) based SDT in a non-connected state comprises: performing a measurement on a first reference signal transmitted by a network node to determine a path loss for the UE; and determining the transmission power for the CG based SDT at least partially based on the determined path loss.

First claim

1 . A method at a user equipment (UE) for controlling transmission power for configured grant (CG) based small data transmission (SDT) in a non-connected state, the method comprising:
performing a measurement on a first reference signal transmitted by a network node to determine a path loss for the UE; and determining the transmission power for the CG based SDT at least partially based on the determined path loss.

2 . The method of claim 1 , further comprising:
receiving a configured grant from the network node which indicates one or more uplink transmission occasions for SDT; and determining a reference signal associated with at least one of the uplink transmission occasions, as the first reference signal.

3 . The method of claim 1 , further comprising:
transmitting, to the network node, one or more data bits for SDT over the at least one uplink transmission occasion associated with the first reference signal.

4 . The method of claim 1 , wherein the first reference signal is a synchronous signal block (SSB) or a Channel State Information-Reference Signal (CSI-RS).

5 . The method of claim 1 , further comprising:
receiving a message which is associated with the first reference signal and broadcasted by the network node.

6 . The method of claim 5 , wherein the message is a Radio Resource Control (RRC) Master Information Block (MIB) message and the first reference signal is a synchronous signal block (SSB) associated with the RRC MIB message.

7 - 14 . (canceled)

15 . The method of claim 1 , wherein the step of determining the transmission power for the CG based SDT at least partially based on the determined path loss comprises:
determining the transmission power for the CG based SDT further based on a PUSCH power control adjustment state f b,f,c (i, l) for active uplink (UL) bandwidth part (BWP) b of carrier f of serving cell c and PUSCH transmission occasion i, wherein the PUSCH power control adjustment state comprises one or more power ramping steps.

16 . The method of claim 15 , wherein the PUSCH power control adjustment state f b,f,c (i, l) is determined as follows:
f b,f,c ( i, l )= f b,f,c ( i− 1 , l )+ k*ΔP rampup,b,f,c where ΔP rampup,b,f,c is a power ramping step, k is the power ramping counter, and l is the index of the PUSCH power control adjustment state f b,f,c (i, l).

17 . The method of claim 1 , further comprising:
suspending power ramping for the UE in response to determining that a second reference signal which is different from the first reference signal is received.

18 . The method of claim 1 , wherein the non-connected state is an RRC_INACTIVE state or an RRC_IDLE state while the connected state is an RRC_CONNECTED state.

19 . A method at a user equipment (UE) for controlling transmission power for configured grant (CG) based small data transmission (SDT) in a non-connected state, the method comprising:
receiving, from a network node, one or more parameters for power control; and determining the transmission power for the CG based SDT at least partially based on the received one or more parameters.

20 . The method of claim 19 , wherein the one or more parameters comprise at least one of:
a parameter indicating a nominal value for CG based SDT power control; one or more parameters indicating one or more P0 values and/or path loss scaling factors; a parameter indicating a reference signal index for path loss estimation; a parameter for determining delta power related to Modulation & Coding Scheme (MCS) used for the CG-based SDT; and a parameter indicating whether TPC accumulation is enabled or not.

21 . The method of claim 19 , wherein at least one of the one or more parameters is received via an RRC message, a Medium Access Control (MAC) Protocol Data Unit (PDU) message, and/or a DCI message, wherein the RRC message is dedicated for the UE's SDT power control and comprises a whole PUSCH-PowerControl Information Element (IE).

22 . (canceled)

23 . The method of claim 21 , wherein the RRC message is an RRC release message which triggers the UE to transition into the non-connected state.

24 . The method of claims 19 , wherein the step of determining the transmission power for the CG based SDT at least partially based on the received one or more parameters comprises:
determining the transmission power for the CG based SDT further based on a parameter indicating a nominal value for power control for Msg3 PUSCH when a 4-step Random Access Channel (RACH) procedure was previously involved or a nominal value for MsgA PUSCH when a 2-step RACH procedure was previously involved, in response to determining that the one or more parameters comprises no parameter indicating a nominal value for CG based SDT power control.

25 . The method of any of claims 19 , wherein the one or more parameters further comprise a parameter indicating which of the P0-PUSCH-AlphaSets is selected if more than one parameter indicating P0-PUSCH-AlphaSets are received.

26 . The method of claim 19 , wherein the step of determining the transmission power for the CG based SDT at least partially based on the received one or more parameters comprises:
determining the transmission power for the CG based SDT further based on a parameter indicating a P0 value and/or a path loss scaling factor for power control for Msg3 PUSCH when a 4-step Random Access Channel (RACH) procedure was previously involved or a P0 value and/or a path loss scaling factor for MsgA PUSCH when a 2-step RACH procedure was previously involved, in response to determining that the one or more parameters comprises no parameter indicating a P0 value for CG based SDT power control and/or no parameter indicating a path loss scaling factor for the UE.

27 . The method of claim 19 , wherein the one or more parameters comprise at least one of:
a parameter indicating an uplink transmission scheme configuration; a parameter indicating an uplink full power mode configuration; and a Sounding Reference Signal (SRS) resource set, wherein the parameter indicating an uplink transmission scheme configuration indicates that only non-Codebook based TX scheme is used for CG-based SDT.

28 . (canceled)

29 . (canceled)

30 . The method of claim 19 , wherein the step of determining the transmission power for the CG based SDT at least partially based on the received one or more parameters comprises:
determining the transmission power for the CG based SDT at least partially based on the received one or more parameters with a predetermined power scaling value being used.

31 . A user equipment (UE), comprising:
a processor; a memory storing instructions which, when executed by the processor, cause the processor to perform:
performing a measurement on a first reference signal transmitted by a network node to determine a path loss for the UE; and
determining the transmission power for the configured grant (CG) based small data transmission (SDT) at least partially based on the determined path loss.

32 - 51 . (canceled)

Assignees

• Ericsson Telefon Ab L M

Inventors

• Lin Zhipeng

Classifications

• H04W52/146 Primary

  Uplink power control · CPC title

• H04W52/36

  with a discrete range or set of values, e.g. step size, ramping or offsets · CPC title

• H04W52/242

  taking into account path loss · CPC title

• H04W52/248

  where transmission power control commands are generated based on a path parameter · CPC title

• H04W52/247

  where the output power of a terminal is based on a path parameter sent by another terminal · CPC title