3GPP TSG-RAN WG1 Meeting #121	R1-2503277
St Julian’s, Malta, May 19-23 2025   

Agenda Item:	9.2.3
Source:	Huawei, HiSilicon
Title:	Discussion on 3-antenna-port UL transmission
Document for:	Discussion and Decision

Conclusion
In this contribution, we have discussed some pending issues related to codebook-based 3Tx UL transmission, and made the following proposals: 
Proposal 1: Update the TS 38.214 draft CR as below:
Proposal 2: Support to introduce a component for FG 59-3-2 to indicate the supported maximum number of SRS ports, the candidate value of which is up to 3. 

3GPP TSG RAN WG1 #121	                   	      R1-2503353
St Julian’s, Malta, May 19th – 23th, 2025

Source: 	vivo
Title:	Discussion on 3-antenna-port UL codebook-based uplink transmission
Agenda Item:	9.2.3
Document for:	Discussion and Decision

Conclusion
As a summary, we have the following TP proposal.
TP 1:
Adopt the following TP in red text for TS38.214 section 6.1.1.1.

3GPP TSG RAN WG1 #121															       R1-2503435 
Malta, MT, May 19th – 23rd, 2025

Agenda Item:		9.2.3
Source:				InterDigital, Inc.
Title:						Remaining Details of Rel-19 CB-based UL for 3TX UE
Document for:		Discussion and Decision

Conclusions
	In this contribution, we discussed additional scope enhancements for 3TX that may be discussed in future releases, and made the following observation and proposal:

Observation 1: In Rel-19, RAN1 developed specifications to support operation of 3TX UEs for a limited set of scenarios. 

Proposal 1: Given the market interest for medium cost UEs, in future releases, expand the specifications of 3TX to support full- and partial-coherent MIMO precoding, full power Mode-1/2, asymmetric STxMP, etc.

3GPP TSG RAN WG1 #121			        R1-2503437
Malta, Ma, May 19th – 23rd, 2025
Agenda Item:		9.2.3
Source:				Moderator (InterDigital, Inc.)
Title:						FL Summary Support for 3TX CB-based Uplink; First Round
Document for:		Discussion and Decision

Conclusion
For a 3TX UE, following agreements for codebook-based transmission can also be extended for non-codebook-based transmission,

Agreement
For 3T3R and 3T6R antenna switching, support the following separate UE capabilities for SRS configuration,
“srs-AntennaSwitching3T6R2SP-1Periodic” to extend srs-AntennaSwitching2SP-1Periodic to the case of 3T6R.
“srs-AntennaSwitching3T3R2SP-1Periodic” to extend srs-AntennaSwitching2SP-1Periodic to the case of 3T3R.

3GPP TSG RAN WG1 #121			        R1-2503438
Malta, MT, May 19th – 23rd, 2025
Agenda Item:		9.2.3
Source:				Moderator (InterDigital, Inc.)
Title:						Summary of Discussion on 3TX CB-based Uplink in RAN1#121
Document for:		Discussion and Decision

Conclusion
For codebook-based PUSCH transmission by a 3TX UE, PUSCH scheduling by DCI format 0_3 is not supported.
Agreement: Adopt the following TP in red text for TS 38.214 section 6.1.1.1.

3GPP TSG RAN WG1 #121                                         R1-2503557
St Julian’s, Malta, May 19th – 23th, 2025

Agenda item:	9.2.3
Source: 	Samsung
Title: 	Views on Rel-19 3-antenna-port codebook-based transmissions
Document for:	Discussion and Decision

Conclusion
In this contribution, the following observation and proposals are given: 

Proposal 1. Adopt the following text proposal expressed by yellow highlight in Clause 7.3.1.1.2 in TS38.212.


Proposal 2. Adopt the following text proposal expressed by yellow highlight in Clause 7.3.1.1.3 in TS38.212.

3GPP TSG RAN WG1 Meeting #121	R1-2503670
St Julian’s, Malta, May 19th – 23th, 2025

Source: 	ZTE Corporation, Sanechips
Title:	Discussion on 3-antenna-port codebook-based transmissions
Agenda item:	9.2.3
Document for:	Discussion and Decision

Conclusion
In this contribution, we provide our views on the 3Tx UL transmission, and we have the following proposals. 
Proposal 1: A maximum of 3 SRS resources per set should be supported for NCB 3Tx transmission.
Further details should be discussed in the UE feature session. 
Text Proposal 1: The following text change should be adopted in clauses 6.2.1.2 in TS 38.214.

3GPP TSG-RAN WG1 Meeting #121	R1- 2503723 
St Julian’s, Malta, May 19th – May 23rd, 2025
Agenda Item:	9.2.3
Source:	Ericsson 
Title:		Remaining issues for 3 Tx UL transmissions
Document for:	Discussion

Conclusion
In this contribution, we addressed the remaining details for the 3 Tx UL MIMO portion of the Rel-19 MIMO work item, and as well as potential future work. Specifically, we focused on finalizing the PTRS-DMRS association indication for non-codebook based transmission with two PTRS ports and enhancing the clarity for the PUSCH power-scaling in the specification. Additionally, given the interest expressed in recent plenaries and the anticipation of new work items, we provided background for potential future UL MIMO enhancements.
This led to the following proposals for RAN1#121 on 3 Tx:
Proposal 1	Conclude that the agreed PTRS-DMRS association indication for non-codebook based PUSCH with two PTRS ports, applicable when up to three SRS resources are configured in an SRS resource set, shall also apply to the case where up to four SRS resources are configured in an SRS resource set, if the configuration of up to four SRS resources in an SRS resource set is agreed.
Proposal 2	Update TS 38.214 to calculate the maximum number of ports supported by the UE in an SRS resource, for scaling of PUSCH transmission power as described in clause 7.1 of [6, TS 38.213], using 3, if [UE feature 59-3-2] is supported, and the maximum number(s) of SRS ports supported by the UE in one SRS resource.
Some observations and proposals regarding potential work related to other UL enhancements can be found in Section 2.3.

3GPP TSG RAN WG1 #121                                                                                   R1-2503788
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	CATT
Title:	Maintenance on 3-antenna-port uplink transmission
Agenda Item:	9.2.3
Document for:	Discussion and Decision

Conclusions
In this contribution, we provided one TP for 3Tx enhancements. The proposal is provided as follows:
Proposal 1: Adopt the following TP on UL 3Tx in section 6.1.1.1 of the draft CR for TS 38.214:

3GPP TSG RAN WG1 #121		                                         R1-2503914
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.2.3
Source:	Lenovo
Title:	Support for 3-antenna-port codebook-based transmissions
Document for:	Discussion

Conclusion
As a summary, we have the following proposals on support for 3-antenna-port codebook-based transmissions:
Proposal 1: Support Rel-18 STxMP schemes for PUSCH transmission for a 3Tx UE.
Proposal 2:For the tables that indicate the second Precoding information for 3Tx PUSCH transmission:
Support same tables for SFN scheme as TDM scheme;
Support Table 1 and Table 2 for SDM scheme.
Proposal 3: Reuse legacy guard period design principle and legacy guard period value for 3T6R antenna switching.
Proposal 4: Support ‘t3r3’ as one downgrading antenna switching configuration value for UE equipped with 4Rx/6Rx/8Rx and indicating capability supportedSRS-TxPortSwitch/srs-AntennaSwitching Beyond4RX-r17/srs-AntennaSwitching8T8R-r18, respectively. 

3GPP TSG RAN WG1 #121		R1-2504029
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.2.3
Source:	Google
Title:	Uplink 3 Ports Codebook based Transmission
Document for:	Discussion/Decision

Conclusion
In this contribution, we provided discussion on uplink 3 ports codebook-based transmission for NR MIMO. Based on the discussion, the following proposals are provided.
Proposal 1: Support Table 1 for PTRS-DMRS association indication when 2-port PT-RS are configured and 4 SRS resources for non-codebook are configured.
Table 1: PTRS-DMRS association indication when 2-port PT-RS are configured and 4 SRS resources for non-codebook are configured


Proposal 2: Clarify whether the 3 ports PUSCH can be scheduled by DCI format 0_3
If it is not supported, endorse TP1 below for 38.214
If it is supported, endorse TP2 below for 38.212

TP1 for 38.214
Reason for change: 3 ports PUSCH cannot be scheduled by DCI format 0_3
Summary of change: Clarify 3 ports PUSCH cannot be scheduled by DCI format 0_3
Consequence if not changed: Inconsistency between 38.212 and 38.214 on whether 3 ports PUSCH can be scheduled by DCI format 0_3
------------------------------- start of TP1 for section 6.1.1.1 for 38.214 -------------------------------
For codebook based transmission with three antenna ports, the UE determines its codebook subsets based on TPMI(s) and upon the reception of higher layer parameter codebookSubset in pusch-Config for PUSCH associated with DCI format 0_1 or 0_3 and codebookSubsetDCI-0-2in pusch-Config for PUSCH associated with DCI format 0_2 which may be configured with 'nonCoherent'.

------------------------------- start of TP1 for section 6.1.1.1 for 38.214 -------------------------------

TP2 for 38.212
Reason for change: 3 ports PUSCH can be scheduled by DCI format 0_3
Summary of change: Clarify 3 ports PUSCH can be scheduled by DCI format 0_3
Consequence if not changed: Inconsistency between 38.212 and 38.214 on whether 3 ports PUSCH can be scheduled by DCI format 0_3
------------------------------- start of TP1 for section 7.3.1.1.4 for 38.212 -------------------------------
 above for the case of tpmi-DCI0-3= type1a or each block above for the case of tpmi-DCI0-3= type2 is defined by the following:
-	0 bits if the higher layer parameter txConfig = nonCodeBook;
-	0 bits for 1 antenna port and if the higher layer parameter txConfig = codebook;
-	4, 5, or 6 bits according to Table 7.3.1.1.2-2 for 4 antenna ports, if txConfig = codebook, ul-FullPowerTransmission is not configured or configured to fullpowerMode2 or configured to fullpower, transform precoder is disabled, and according to the values of higher layer parameters maxRank, and codebookSubset;
-	4 or 5 bits according to Table 7.3.1.1.2-2A for 4 antenna ports, if txConfig = codebook, ul-FullPowerTransmission =fullpowerMode1, maxRank=2, transform precoder is disabled, and according to the value of higher layer parameter codebookSubset;
-	4 or 6 bits according to Table 7.3.1.1.2-2B for 4 antenna ports, if txConfig = codebook, ul-FullPowerTransmission =fullpowerMode1, maxRank=3 or 4, transform precoder is disabled, and according to the value of higher layer parameter codebookSubset;
-	2, 4, or 5 bits according to Table 7.3.1.1.2-3 for 4 antenna ports, if txConfig = codebook, ul-FullPowerTransmission is not configured or configured to fullpowerMode2 or configured to fullpower, and according to whether transform precoder is enabled or disabled, and the values of higher layer parameters maxRank and codebookSubset;
-	3 or 4 bits according to Table 7.3.1.1.2-3A for 4 antenna ports, if txConfig = codebook, ul-FullPowerTransmission =fullpowerMode1, and according to whether transform precoder is enabled, or disabled and maxRank=1, and the value of higher layer parameter codebookSubset;
-	2 or 4 bits according to Table7.3.1.1.2-4 for 2 antenna ports, if txConfig = codebook, ul-FullPowerTransmission is not configured or configured to fullpowerMode2 or configured to fullpower, transform precoder is disabled, and according to the values of higher layer parameters maxRank and codebookSubset;
-	2 bits according to Table 7.3.1.1.2-4A for 2 antenna ports, if txConfig = codebook, ul-FullPowerTransmission =fullpowerMode1, transform precoder is disabled, maxRank=2, and codebookSubset=nonCoherent;
-	1 or 3 bits according to Table7.3.1.1.2-5 for 2 antenna ports, if txConfig = codebook, ul-FullPowerTransmission is not configured or configured to fullpowerMode2 or configured to fullpower, and according to whether transform precoder is enabled or disabled, and the values of higher layer parameters maxRank and codebookSubset;
-	2 bits according to Table 7.3.1.1.2-5A for 2 antenna ports, if txConfig = codebook, ul-FullPowerTransmission =fullpowerMode1, and according to whether transform precoder is enabled, or disabled and maxRank=1, and the value of higher layer parameter codebookSubset.
-	3 bits according to Table 7.3.1.1.2-5T for 3 antenna ports, if txConfig = codebook, ul-FullPowerTransmission is not configured or configured to fullpower, transform precoder is disabled, and according to the values of higher layer parameters maxRank; 
-	2 bits according to Table 7.3.1.1.2-5U for 3 antenna ports, if txConfig = codebook, ul-FullPowerTransmission is not configured or configured to fullpower, and according to whether transform precoder is enabled or disabled, and the values of higher layer parameters maxRank; 
------------------------------- start of TP1 for section 7.3.1.1.4 for 38.212 -------------------------------

Proposal 3: Endorse the following TP for 38.212 to capture the agreement for PTRS and DMRS association correctly.
Reason for change: 3 ports PUSCH can be scheduled by DCI format 0_3
Summary of change: Clarify 3 ports PUSCH can be scheduled by DCI format 0_3
Consequence if not changed: Inconsistency between 38.212 and 38.214 on whether 3 ports PUSCH can be scheduled by DCI format 0_3
------------------------------- start of TP for 38.212 -------------------------------
7.3.1.1.2	Format 0_1

-	1 bit when two PTRS ports are configured by maxNrofPorts in PTRS-UplinkConfig for 3 antenna ports, SRS resource set indicator field is absent or SRS resource set indicator field is present and equals "00" or "01", maxRank<=3 or maxMIMO-Layers<=3 (when 3 SRS resources in the corresponding SRS resource set with the usage of value ‘nonCodebook’ are configured), this field indicates the association between PTRS port(s) and DMRS port(s) corresponding to SRS resource indicator field and/or Precoding information and number of layers field according to Tables 7.3.1.1.2-26B.

7.3.1.1.3	Format 0_2

-	1 bit when two PTRS ports are configured by maxNrofPorts in PTRS-UplinkConfig for 3 antenna ports, SRS resource set indicator field is absent or SRS resource set indicator field is present and equals "00" or "01", maxRankDCI-0-2<=3 or maxMIMO-LayersDCI-0-2<=3 (when 3 SRS resources in the corresponding SRS resource set with the usage of value ‘nonCodebook’ are configured), this field indicates the association between PTRS port(s) and DMRS port(s) corresponding to SRS resource indicator field and/or Precoding information and number of layers field according to Tables 7.3.1.1.2-26B.


------------------------------- start of TP for 38.212 -------------------------------

3GPP TSG RAN WG1 Meeting #121		R1-2404078
Malta, 19 – 23 May 2025

Agenda item:       9.2.3
Source: 	Nokia
Title: 	On the support for 3-antenna-port codebook based transmissions
Document for:     Discussion and Decision

1	

Conclusions
In our contribution, related uplink 3Tx topics are discussed. Here is the list of our proposals:
Proposal 1: A UE may be configured with only one of the following configurations depending on the indicated UE capability supportedSRS-TxPortSwitchBeyond4Rx:
't1r1' for 1T1R, 
't2r2' for 2T2R, 
't1r2' for 1T2R, 
't4r4' for 4T4R, 
't2r4' for 2T4R, 
't1r4' for 1T4R, 
't2r6' for 2T6R, 
't1r6' for 1T6R, 
't4r8' for 4T8R, 
't2r8' for 2T8R, 
't1r8' for 1T8R
‘t3r3’ for 3T3R,
't3r6' for 3T6R,

3GPP TSG RAN WG1 #121	              	     R1-2504230
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	OPPO
Title:	Discussion on 3-antenna-port uplink transmissions
Agenda Item:	9.2.3
Document for:	Discussion and Decision

Conclusions
In this contribution, we provide two text proposals for 3-antenna-port uplink transmissions as following.
Proposal 1: Apply the text proposal 1 to the endorsed 38.214 draft CR.

3GPP TSG RAN WG1 #121                                                                     R1- 2504313	
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.2.3
Source:	Apple Inc.
Title:	Remaining issues on R19 MIMO 3Tx transmission
Document for:	Discussion/Decision

Conclusion
In this contribution, we shared our views on remaining issues regarding R19 MIMO 3Tx UL transmission. The following proposal is made:
Proposal 1: Adopt the following TP in 38.214, Sec. 6.2.1, for R19

The UE is not expected to be configured with an SRS resource which is in both SRS-ResourceSet with usage ‘codebook’ and ‘antennaSwitching’ and the two SRS-ResourceSet with usage ‘codebook’ and ‘antennaSwitching’ have different configuration for higher layer parameter [RRC parameter].

3GPP TSG RAN WG1 #121	R1-2504446
St Julian’s, Malta, May 19th – 23th, 2025
Source:	Sharp
Title:	Support for 3-antenna-port transmission
Agenda Item:	9.2.3
Document for:	Discussion and Decision

Conclusion
In this contribution, we have the following proposal:
Proposal 1: We support the following way to enable non-codebook-based 3Tx transmission:
New RRC parameter is introduced; or
Another description for non-codebook is added to 4portSRS_3TX.
Proposal 2: We do NOT support that UE splits a linear SRS power equally across multiple combs.

3GPP TSG RAN WG1 #121		 R1- 2504456
Malta, MT, May 19th – 23st, 2025

Agenda Item:	9.2.3
Source:	China Telecom
Title:	Discussions on 3-antenna-port UL transmission
Document for:	Discussion
1		

Conclusion
In this contribution, we discuss the potential design of synchronization, random access and scheduling, and have the following observations and proposals: 

4