Content for TR 38.880 Word version: 18.0.0

3.1 Terms 3.2 Symbols 3.3 Abbreviations 4.1 Introduction 4.2 TR Maintenance
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1 Scope p. 8

The present document is a technical report for UE requirements for 3Tx inter-band UL CA and EN-DC under Rel-18 time-frame. The purpose is to gather the relevant background information and studies of these 3Tx band combinations.

This TR contains the RF requirements of band combination specific part. The actual requirements are added to the corresponding technical specifications.

2 References p. 8

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

[1]

TR 21.905: "Vocabulary for 3GPP Specifications".

[2]

TS 38.101-1: "NR; User Equipment (UE) radio transmission and reception; Part 1: Range 1 Standalone".

[3]

TS 38.101-3: "NR; User Equipment (UE) radio transmission and reception; Part 3: Range 1 and Range 2 Interworking operation with other radios".

[4]

WI description, RP-231719: "WID revision for Core part 4Rx handheld UE for low NR bands (1GHz) and/or 3Tx for NR inter-band UL Carrier Aggregation (CA) and EN-DC"

[5]

WI description, RP-232674: "New WID: Rel-18 new basket WI for 3Tx inter-band UL CA and EN-DC"

3 Definitions of terms, symbols and abbreviations p. 8

3.1 Terms p. 8

For the purposes of the present document, the terms given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.

3Tx:

UE transmit with one Tx chain on one band and two Tx chains on the other band in CA or EN-DC band combinations.

Carrier aggregation:

Aggregation of two or more component carriers in order to support wider transmission bandwidths.

Inter-band carrier aggregation:

Carrier aggregation of component carriers in different operating bands.

3.2 Symbols p. 8

For the purposes of the present document, the following symbols apply:

ΔR_IB,c

Allowed reference sensitivity relaxation due to support for inter-band CA operation, for serving cell c

ΔT_IB,c

Allowed maximum configured output power relaxation due to support for inter-band CA operation, inter-band NR-DC operation and due to support for SUL operations, for serving cell c

3.3 Abbreviations p. 9

For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.

Carrier Aggregation

Dual Connectivity

IMD

Inter-modulation

MSD

Maximum Sensitivity Deduction

SCS

Subcarrier spacing

4 Background p. 9

4.1 Introduction p. 9

General requirements for 3Tx feature was introduced in Rel-18 RAN4 specification TS 38.101-1 and TS 38.101-3 via WI [4]. After that, more band combinations are proposed and introduced via basket WI [5].

The power capabilities considered in this technical report includes:

CA power class or EN-DC power class is PC2

PC3 FDD band 1Tx + PC2 TDD band 2Tx (UL MIMO and TxD)

PC3 FDD band 1Tx + PC3 TDD band 2Tx (UL MIMO)

PC3 TDD band 1Tx + PC2 TDD band 2Tx (UL MIMO)

CA power class or EN-DC power class is PC1.5

PC3 FDD band 1Tx + PC1.5 TDD band 2Tx (UL MIMO and TxD)

The present document is a technical report for UE requirements for the newly introduced band combinations with 3Tx inter-band UL CA and EN-DC under Rel-18 time-frame. It covers the RF requirements for each band combination specific issues (i.e. one sub-clause defined per band combination) mainly MSD analysis caused by harmonic mixing, cross band leakage and IMD issue. It should be noticed that the MSD for harmonic interference is not considered here since in Rel-18 the band combinations considered mainly 1Tx in low frequency bands + 2Tx in high frequency bands as seen from the WI scope [5].

The below agreements can be followed when introduce new 3Tx band combinations:

For 3Tx PC2/PC1.5 harmonic mixing and cross-band leakage MSD:

Reuse the MSD of 2Tx band combination for 3Tx band combination as long as the aggressor TDD band has same power class.

For 3Tx PC2 IMD MSD:

The IMD MSD specified based on 1Tx-1Tx UL configuration are applicable for 1Tx-2Tx UL configuration.

For 3Tx PC1.5 IMD MSD:

23+27.8 is used as the power configuration in the 3Tx PC1.5 IMD MSD calculation where band A is 23dBm and band B is 24.8dBm+24.8dBm with 2Tx.

For the band combinations whose 2Tx MSD is not specified in the spec yet, 3Tx MSD needs to be evaluated. And it is encouraged to align the requirements between 2Tx and 3Tx band combinations.

4.2 TR Maintenance p. 10

A single company is responsible for introducing all approved TPs in the current TR, i.e. TR editor. However, it is the responsibility of the contact person of each band combination to ensure that the TPs related to the band combination have been implemented.