UL CoMP(eRAN8.1_03)

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UL CoMP Feature Parameter

Description

Issue 03

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1 About This Document... 1

1.1 Scope... 1

1.2 Intended Audience...1

1.3 Change History... 2

1.4 Differences Between eNodeB Types... 8

2 Overview... 9

2.1 Background...9

2.2 Introduction... 9

2.3 Related Concepts... 11

2.4 Application Scenarios...13

2.4.1 LOFD-001066 Intra-eNodeB UL CoMP...14

2.4.2 LOFD-070222 Intra-eNodeB UL CoMP Phase II...14

2.4.3 LOFD-070223 UL CoMP based on Coordinated BBU...15

2.4.4 LOFD-081219 UL CoMP Based on Relaxed Backhaul...16

2.4.5 UL CoMP in SFN Scenarios... 17

2.5 Benefits...18

2.5.1 Sources of Gains...19

2.5.2 Areas Benefiting from UL CoMP... 21

2.5.3 Level of Gains... 23

2.6 Evolution of UL CoMP... 24

3 Technical Description...28

3.1 Basic Process... 29

3.2 Selection of UL CoMP UEs and Coordinated Cells...30

3.3 Joint Reception by Multiple Cells' Antennas... 34

4 Related Features...35

4.1 Relationships Between UL CoMP Features... 35

4.2 Features Related to LOFD-001066 Intra-eNodeB UL CoMP...36

4.3 Features Related to LOFD-070222 Intra-eNodeB UL CoMP Phase II...38

4.4 Features Related to LOFD-070223 UL CoMP based on Coordinated BBU...39

4.5 Features Related to LOFD-081219 UL CoMP Based on Relaxed Backhaul...40

5 Network Impact... 42

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5.2 LOFD-070222 Intra-eNodeB UL CoMP Phase II...42

5.3 LOFD-070223 UL CoMP based on Coordinated BBU...43

5.4 LOFD-081219 UL CoMP Based on Relaxed Backhaul...43

6 Engineering Guidelines for LOFD-001066 Intra-eNodeB UL CoMP... 44

6.1 When to Use LOFD-001066 Intra-eNodeB UL CoMP...44

6.2 Required Information... 44 6.3 Planning... 45 6.4 Deployment... 45 6.4.1 Requirements... 45 6.4.2 Data Preparation... 48 6.4.3 Precautions...52 6.4.4 Hardware Adjustment...52 6.4.5 Activation... 52

6.4.5.1 Using the CME to Perform Batch Configuration for Newly Deployed eNodeBs...52

6.4.5.2 Using the CME to Perform Batch Configuration for Existing eNodeBs... 52

6.4.5.3 Using the CME to Perform Single Configuration... 53

6.4.5.4 Using MML Commands...54

6.4.6 Activation Observation...57

6.4.6.2 Using Signaling... 58

6.4.6.3 Querying the Number of UL CoMP UEs in a Cell on the U2000 Client... 60

6.4.6.4 Querying the UL CoMP Status of UEs on the U2000 Client...63

6.4.6.5 Using Counters... 66

6.4.7 Reconfiguration... 68

6.4.8 Deactivation...69

6.4.8.1 Using the CME to Perform Batch Configuration... 69

6.5 Performance Monitoring...70

6.6 Parameter Optimization...72

6.7 Troubleshooting... 74

7 Engineering Guidelines for LOFD-070222 Intra-eNodeB UL CoMP Phase II... 76

7.1 When to Use LOFD-070222 Intra-eNodeB UL CoMP Phase II...76

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7.4.5.4 Using MML Commands...86 7.4.6 Activation Observation...89 7.4.6.1 Using MML Commands...89 7.4.6.2 Using Signaling... 89 7.4.6.3 Using Counters... 91 7.4.7 Reconfiguration... 91 7.4.8 Deactivation...91

7.6 Parameter Optimization...93

8 Engineering Guidelines for LOFD-070223 UL CoMP based on Coordinated BBU... 96

8.1 When to Use LOFD-070223 UL CoMP based on Coordinated BBU...96

8.4.5.4 Using MML Commands...106 8.4.6 Activation Observation... 110 8.4.6.1 Using MML Commands... 110 8.4.6.2 Using Signaling...110 8.4.6.3 Using Counters... 112 8.4.7 Reconfiguration... 112 8.4.8 Deactivation... 112

8.4.8.3 Using MML Commands... 113

8.6 Parameter Optimization... 114

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9.1 When to Use LOFD-081219 UL CoMP Based on Relaxed Backhaul... 117 9.2 Required Information...117 9.3 Planning... 118 9.4 Deployment...118 9.4.1 Requirements... 118 9.4.2 Data Preparation... 120 9.4.3 Precautions...123 9.4.4 Hardware Adjustment...124 9.4.5 Activation... 124

9.4.5.4 Using the CME to Perform Feature Configuration... 126

9.4.5.5 Using MML Commands...127 9.4.6 Activation Observation...128 9.4.6.1 Using MML Commands...128 9.4.6.2 Using Counters... 129 9.4.7 Reconfiguration... 129 9.4.8 Deactivation...129

9.4.8.3 Using MML Commands...129 9.5 Performance Monitoring...130 9.6 Parameter Optimization...131 9.7 Troubleshooting... 131

10 Parameters...133

11 Counters... 157

12 Glossary...162

13 Reference Documents... 163

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1

About This Document

1.1 Scope

This document describes uplink coordinated multipoint reception (UL CoMP), including its technical principles, related features, network impact, and engineering guidelines. This document covers the following features:

l LOFD-001066 Intra-eNodeB UL CoMP

l LOFD-070222 Intra-eNodeB UL CoMP Phase II l LOFD-070223 UL CoMP Based on Coordinated BBU l LOFD-081219 UL CoMP Based on Relaxed Backhaul This document applies to the following eNodeBs.

eNodeB Type Model

Macro 3900 series eNodeB LampSite DBS3900 LampSite

Any managed objects (MOs), parameters, alarms, or counters described herein correspond to the software release delivered with this document. Any future updates will be described in the product documentation delivered with future software releases.

This document applies only to LTE FDD. Any "LTE" in this document refers to LTE FDD, and "eNodeB" refers to LTE FDD eNodeB.

1.2 Intended Audience

This document is intended for personnel who: l Need to understand the features described herein l Work with Huawei products

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1.3 Change History

This section provides information about the changes in different document versions. There are two types of changes:

l Feature change

Changes in features and parameters of a specified version as well as the affected entities l Editorial change

Changes in wording or addition of information and any related parameters affected by editorial changes. Editorial change does not specify the affected entities.

eRAN8.1 03 (2015-08-31)

This issue includes the following changes.

Change

Type Change Description ParameterChange AffectedEntity

Feature change

None None Macro

eNodeBs Editorial

change

Deleted 3.3 "Event A3 Measurement Reporting", and added "RSRP Measurement" to 3.2 Selection of UL CoMP UEs and Coordinated Cells.

None None

eRAN8.1 02 (2015-04-30)

Change

Feature change

Estimated the level of gains provided by UL CoMP. For details, see 2.5.3 Level of Gains.

None Macro

eNodeBs

Added the impact on CAMC. For details, see 4.2 Features Related to

LOFD-001066 Intra-eNodeB UL CoMP.

None Macro

eNodeBs

Modified the impact on CA features. For details, see 4.2 Features Related to LOFD-001066 Intra-eNodeB UL CoMP, 4.3 Features Related to LOFD-070222 Intra-eNodeB UL CoMP Phase II, and 4.4 Features Related to LOFD-070223 UL CoMP based on Coordinated BBU.

None Macro

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Change

Editorial change

Revised descriptions in this document. None None

eRAN8.1 01 (2015-03-23)

Change

Feature change

To enable the following features to support macro-micro UL CoMP: l LOFD-001066 Intra-eNodeB UL

CoMP

l LOFD-070222 Intra-eNodeB UL CoMP Phase II

l LOFD-070223 UL CoMP Based on Coordinated BBU

Optimized the following operations: l Data preparation

l Batch configuration for newly deployed eNodeBs using the CME l Activation using MML commands For details, see engineering guidelines.

None Macro

eNodeBs

Editorial change

Revised descriptions in this document. None None

eRAN8.1 Draft A (2015-01-15)

Compared with Issue 04 (2014-12-30) of eRAN7.0, Draft A (2015-01-15) of eRAN8.1 includes the following changes.

Change

Type Change Description Parameter Change AffectedEntity

Feature change

Added LampSite eNodeBs' support for LOFD-001066 Intra-eNodeB UL CoMP and

LOFD-070222 Intra-eNodeB UL CoMP Phase II.

For details, see 1.4 Differences Between eNodeB Types.

None Macro and

LampSite eNodeBs

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Change

Added the feature LOFD-081219 UL CoMP Based on Relaxed Backhaul.

For details, see the following chapters:

l 2 Overview

l 4 Related Features

l 5 Network Impact

l 9 Engineering Guidelines for LOFD-081219 UL CoMP Based on Relaxed Backhaul

l Added the UlJROverRelaxedB HSw option to the ENodeBAlgoSwitch. OverBBUsSwitch parameter. l Added the CellUlCompAlgo.Ul CompA3OffsetForRe laxedBH parameter. Macro eNodeBs

Added the support for

LOFD-070223 UL CoMP Based on Coordinated BBU in

distributed and centralized +distributed Cloud BB modes. For details, see the following sections:

l 2.4.3 LOFD-070223 UL CoMP based on Coordinated BBU

l 5.3 LOFD-070223 UL CoMP based on Coordinated BBU

None Macro

eNodeBs

Added the support for intra-BBP 3-cell UL CoMP in LOFD-001066 Intra-eNodeB UL CoMP.

For details, see the following sections: l 2.4.1 LOFD-001066 Intra-eNodeB UL CoMP l 2.6 Evolution of UL CoMP l 6.4.2 Data Preparation Added the UlJointReception3CellS witch option to the CellAlgoSwitch.Uplink CompSwitch parameter.

Macro and LampSite eNodeBs

Added an eX2 QoS handling mechanism to LOFD-081219 UL CoMP Based on Relaxed

Backhaul.

For details, see 4.5 Features Related to LOFD-081219 UL CoMP Based on Relaxed Backhaul.

None Macro

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Change

Added the UL CoMP capability of the LBBPd3, which supports six 2T4R cells.

For details, see the following sections:

l 2.6 Evolution of UL CoMP

l "Requirements" in

"Deployment" in engineering guidelines for each feature

None Macro and

LampSite eNodeBs

Enabled LOFD-001066 Intra-eNodeB UL CoMP,

LOFD-070222 Intra-eNodeB UL CoMP Phase II, and

LOFD-070223 UL CoMP Based on Coordinated BBU to support macro-micro UL CoMP. For details, see the following sections:

l 2.2 Introduction

l 2.4 Application Scenarios

l 3.2 Selection of UL CoMP UEs and Coordinated Cells

l "Data Preparation" and "Activation" in engineering guidelines for each feature

Added the following options to the CellAlgoSwitch.Uplink CompSwitch parameter: l UlHetnetJointRecep-tionSwitch l UlHetnetCompManua lNcellCfgSw l UlHetnetCompOnUl RsrpSw Macro eNodeBs

Added the mutually exclusive relationships between the UL CoMP features and the following SFN features: LOFD-081208 Inter-eNodeB SFN Based on Coordinated BBU and LOFD-081209 Inter-eNodeB adaptive SFN/SDMA Based on Coordinated BBU.

For details, see 4 Related Features.

None Macro and

LampSite eNodeBs

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Change

Added the support for 1R UL CoMP and 1R+2R UL CoMP in LOFD-001066 Intra-eNodeB UL CoMP, LOFD-070222 Intra-eNodeB UL CoMP Phase II, and LOFD-070223 UL CoMP Based on Coordinated BBU.

l 2.6 Evolution of UL CoMP

l "Requirements" in

"Deployment" in engineering guidelines for each feature

Added the CellAlgoSwitch.UlJRA ntNumCombSw parameter. Macro and LampSite eNodeBs

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Change

Added the collaboration between the UL CoMP features and the SFN features LOFD-003029 SFN and LOFD-070205 Adaptive SFN/ SDMA, and added restrictions on the collaboration.

Added the impact of these SFN features on LOFD-001066 Intra-eNodeB UL CoMP,

LOFD-070222 Intra-eNodeB UL CoMP Phase II, and

LOFD-070223 UL CoMP Based on Coordinated BBU. Added the mutually exclusive relationships between these SFN features and LOFD-081219 UL CoMP Based on Relaxed Backhaul.

l 2.4.5 UL CoMP in SFN Scenarios

l 3.2 Selection of UL CoMP UEs and Coordinated Cells

l "Impacted Features" of LOFD-001066 Intra-eNodeB UL CoMP, LOFD-070222 Intra-eNodeB UL CoMP Phase II, and LOFD-070223 UL CoMP Based on Coordinated BBU as well as "Mutually Exclusive Features" of LOFD-081219 UL CoMP Based on Relaxed Backhaul in

4 Related Features

l "Deployment" and "Parameter Optimization" in engineering guidelines for LOFD-001066 Intra-eNodeB UL CoMP, LOFD-070222 Intra-eNodeB UL CoMP Phase II, and LOFD-070223 UL CoMP Based on Coordinated BBU

None Macro and

LampSite eNodeBs

Editorial change

Revised descriptions in this document.

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1.4 Differences Between eNodeB Types

Feature Support by Macro, Micro, and LampSite eNodeBs

Feature ID Feature

Name Supported byMacro

eNodeBs

Supported by

Micro eNodeBs Supportedby

LampSite eNodeBs LOFD-001066 Intra-eNodeB UL CoMP Yes No Yes LOFD-070222 Intra-eNodeB UL CoMP Phase II Yes No Yes LOFD-070223 UL CoMP based on Coordinated BBU Yes No No LOFD-081219 UL CoMP Based on Relaxed Backhaul Yes No No

Function Implementation in Macro, Micro, and LampSite eNodeBs

l This feature is not supported by micro eNodeBs.

l The features described in this document are implemented in the same way on macro and LampSite eNodeBs.

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2

Overview

2.1 Background

Intra-cell interference in Long Term Evolution (LTE) is effectively eliminated by orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO). The two technologies use low-rate orthogonal subcarriers to transmit high-rate data flows. However, inter-cell interference cannot be effectively mitigated by these technologies. When intra-frequency cells are deployed to achieve higher spectral efficiency, cell edge users (CEUs) experience interference from neighboring cells and their uplink throughput is significantly reduced.

To mitigate inter-cell interference, uplink coordinated multipoint reception (UL CoMP) has been introduced and allowed to be implemented under proprietary schemes since 3GPP Release 8. By sharing channel status information and user data between neighboring cells and converting interference into useful information, UL CoMP mitigates interference between these cells, thereby enhancing cell coverage, improving cell performance, and increasing uplink CEU throughput.

2.2 Introduction

UL CoMP is a multipoint reception technology. It coordinates the antennas of multiple cells to receive and combine signals from a piece of user equipment (UE). UL CoMP provides signal combining gains, interference mitigation gains, or both for a single UE.

UL CoMP is similar to joint reception by the antennas of a single cell, with the following differences:

l UL CoMP reuses existing antennas, without adding antennas to cells.

l UL CoMP provides lower gains, as the signal power received in each cell varies.

UL CoMP Classification

The following table describes UL CoMP classification by application scenario, coordination scope, and transport bandwidth overhead. In this table, BBP stands for baseband processing unit, and BBU stands for baseband unit.

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Table 2-1 UL CoMP classification

Category Type Feature

Macro-macro UL CoMP

Intra-BBP UL CoMP

LOFD-001066 Intra-eNodeB UL CoMP

Intra-BBU inter-BBP UL CoMP

LOFD-070222 Intra-eNodeB UL CoMP Phase II

Inter-BBU UL CoMP

LOFD-070223 UL CoMP Based on Coordinated BBU

UL CoMP based on relaxed backhaul

LOFD-081219 UL CoMP Based on Relaxed Backhaul

Macro-micro UL CoMP

Intra-BBP UL CoMP

Inter-BBU UL CoMP

Micro-micro UL CoMP

Intra-BBP UL CoMP

Inter-BBU UL CoMP

NOTE

UL CoMP is categorized by application scenario: l Macro-macro UL CoMP is performed in macro cells.

l Macro-micro UL CoMP is performed in macro and micro cells. The UE must be a type-1 UL CoMP UE (as defined in 2.3 Related Concepts), the serving cell must be a macro cell, and coordinated cells must be micro cells.

l Micro-micro UL CoMP is performed in micro cells.

l A macro cell is characterized by high transmit power and large coverage area, and specified by the Cell Scale Indication parameter.

l A micro cell is characterized by low transmit power and small coverage area, and specified by the Cell Scale Indication parameter.

UL CoMP is divided into different types in each category based on coordination scope and transport bandwidth overhead:

"Relaxed Backhaul" in the feature name indicates that the feature is applicable when BBUs are connected through an IP RAN with the transmission delay less than 4 ms.

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LOFD-001066 Intra-eNodeB UL CoMP

LOFD-001066 Intra-eNodeB UL CoMP uses intra-BBP cell antennas to receive signals from a UE. The serving and coordinated cells are set up on the same BBP and exchange

information within this BBP. .

LOFD-070222 Intra-eNodeB UL CoMP Phase II

LOFD-070222 Intra-eNodeB UL CoMP Phase II uses intra-BBU inter-BBP cell antennas to receive signals from a UE. The serving and coordinated cells are set up on different BBPs in the same BBU, and they exchange information between the BBPs.

LOFD-070223 UL CoMP based on Coordinated BBU

LOFD-070223 UL CoMP based on Coordinated BBU uses inter-BBU cell antennas to jointly receive signals from a UE. The serving and coordinated cells are set up on different BBUs, and they exchange information between the BBUs through universal switching units (USUs).

LOFD-081219 UL CoMP Based on Relaxed Backhaul

LOFD-081219 UL CoMP Based on Relaxed Backhaul uses inter-BBU cell antennas to receive signals from a UE. The serving cell and coordinated cells exchange information between BBUs through an existing IP transport network, without additional USUs.

2.3 Related Concepts

UL CoMP UE

A UL CoMP UE is a UE whose signals are jointly received by the antennas of multiple cells. There are two types of UL CoMP UE:

l Type-1 UL CoMP UE, also called type-1 UE, is located at the cell edge and expected to benefit from signal combining gains.

l Type-2 UL CoMP UE, also called type-2 UE, is located anywhere in a cell, affected by interference from a type-1 UE, expected to benefit from interference mitigation gains.

NOTE

If a UE meets both type-1 and type-2 UE conditions, it is categorized as a type-1 UE.

2-Cell UL CoMP

2-cell UL CoMP uses the antennas of two separate cells to receive signals from a single UE. If each of the two cells has two antennas, a total of four antennas can be used to jointly receive UE signals over the physical uplink shared channel (PUSCH) to improve signal quality.

3-Cell UL CoMP

3-cell UL CoMP uses the antennas of three separate cells to receive signals from a single UE. If each of the three cells has two antennas, a total of six antennas can be used to jointly receive UE signals over the PUSCH to improve signal quality.

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NOTE

3-cell UL CoMP means that a maximum of two neighboring cells can be selected to work with the serving cell of a UE. 3-cell UL CoMP in the serving cell does not require 3-cell UL CoMP to be activated in the neighboring cells.

Coordinated Cell

A coordinated cell is a UE-level concept. It works with the serving cell of a UE to implement UL CoMP.

The eNodeB dynamically selects coordinated cells for a UL CoMP UE. This UE will have at least one coordinated cell but may have different coordinated cells at different moments.

Coordinated Set

A coordinated set is a UE-level concept. It contains a UE's serving cell and its neighboring cells that work with the serving cell for UL CoMP.

Coordinated Cell List

A coordinated cell list is a cell-level concept. It contains the local cell's neighboring cells that can work with the local cell for UL CoMP.

Connection Set

A connection set is a cell-level concept. It contains a local cell and all cells that have routes to this local cell. The size of a connection set depends on hardware specifications.

Example

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Figure 2-1 Diagram illustrating the related concepts

Concept Instance

UL CoMP UE UE 0

Serving cell of UE 0 Cell 3

Coordinated cells of UE 0 Cells 1 and 2 Coordinated set of UE 0 {Cells 1, 2, and 3} Coordinated cell list of cell 3 Cells 1, 2, 4, and 5 Connection set of cell 3 {Cells 0, 1, 2, 3, 4, and 5}

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2.4.1 LOFD-001066 Intra-eNodeB UL CoMP

When LOFD-001066 Intra-eNodeB UL CoMP is enabled, the following types of intra-BBP UL CoMP are supported:

l Intra-BBP macro-macro UL CoMP l Intra-BBP macro-micro UL CoMP l Intra-BBP micro-micro UL CoMP

The following figure uses macro-macro UL CoMP as an example to illustrate intra-BBP UL CoMP.

l If 3-cell UL CoMP is disabled, the serving cell for UE 0 will be cell 3 and the

coordinated cell will be either 1 or 2. The coordinated set contains either cells 1 and 3 or cells 2 and 3.

l If 3-cell UL CoMP is enabled, the serving cell for UE 0 will be cell 3 and the

coordinated cells will be 1 and 2. The coordinated set of UE 0 contains all three cells.

Figure 2-2 Intra-BBP UL CoMP

2.4.2 LOFD-070222 Intra-eNodeB UL CoMP Phase II

When LOFD-070222 Intra-eNodeB UL CoMP Phase II is enabled together with

LOFD-001066 Intra-eNodeB UL CoMP, the following types of intra-BBU UL CoMP are supported:

l Intra-BBU inter-BBP macro-macro UL CoMP l Intra-BBU inter-BBP macro-micro UL CoMP l Intra-BBU inter-BBP micro-micro UL CoMP

The following figure uses macro-macro UL CoMP as an example to illustrate intra-BBU inter-BBP UL CoMP.

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l If 3-cell UL CoMP is enabled, the serving cell for UE 0 will be cell 3 and the

coordinated cells will be 1 and 2. The coordinated set of UE 0 contains all three cells.

Figure 2-3 Intra-BBU inter-BBP UL CoMP

2.4.3 LOFD-070223 UL CoMP based on Coordinated BBU

When LOFD-070223 UL CoMP Based on Coordinated BBU is enabled together with LOFD-001066 Intra-eNodeB UL CoMP and LOFD-070222 Intra-eNodeB UL CoMP Phase II, the following types of inter-BBU UL CoMP based on coordinated BBU are supported: l Inter-BBU macro-macro UL CoMP with BBUs connected in centralized, distributed, or

centralized+distributed mode

l Inter-BBU macro-micro UL CoMP with BBUs connected in centralized, distributed, or centralized+distributed mode

l Inter-BBU micro-micro UL CoMP with BBUs connected in centralized, distributed, or centralized+distributed mode

Figure 2-4 uses macro-macro UL CoMP as an example to illustrate inter-BBU UL CoMP. l If 3-cell UL CoMP is disabled, the serving cell for UE 0 will be cell 3 and the

l If 3-cell UL CoMP is enabled, the serving cell for UE 0 will be cell 3 and the coordinated cells will be 1 and 2. The coordinated set contains all three cells.

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Figure 2-4 Inter-BBU UL CoMP with BBUs connected in centralized, distributed, or

centralized+distributed mode

Table 2-2 Application scenarios in different versions

Scenario eRAN7.0 eRAN8.1

USU interconnection mode One-level USU interconnection

Two-level USU interconnection Cloud BB networking

mode

Centralized mode Centralized, distributed, or centralized+distributed mode

NOTE

For details about the Cloud BB networking modes, see USU3900-based Multi-BBU Interconnection

Feature Parameter Description and USU3910-based Multi-BBU Interconnection Feature Parameter Description.

2.4.4 LOFD-081219 UL CoMP Based on Relaxed Backhaul

When LOFD-081219 UL CoMP Based on Relaxed Backhaul is enabled together with LOFD-001066 Intra-eNodeB UL CoMP, LOFD-070222 Intra-eNodeB UL CoMP Phase II, and LOFD-001048 TTI Bundling, macro-macro UL CoMP based on relaxed backhaul is supported.

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l If 3-cell UL CoMP is enabled, the serving cell for UE 0 will be cell 2 and the coordinated cells will be 1 and 3. The coordinated set contains all three cells.

Figure 2-5 Inter-BBU UL CoMP based on relaxed backhaul

2.4.5 UL CoMP in SFN Scenarios

When the single frequency network (SFN) feature LOFD-003029 SFN or LOFD-070205 Adaptive SFN/SDMA is enabled together with one of the following UL CoMP features: l LOFD-001066 Intra-eNodeB UL CoMP

l LOFD-070222 Intra-eNodeB UL CoMP Phase II l LOFD-070223 UL CoMP Based on Coordinated BBU The following types of UL CoMP are supported:

l UL CoMP between SFN and non-SFN cells l UL CoMP between SFN cells

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Figure 2-6 UL CoMP in SFN scenarios

UL CoMP Between SFN and Non-SFN Cells

If 3-cell UL CoMP is disabled, the serving cell for UE 0 in Figure 2-6 will be cell 3, and the coordinated cell will be either physical cell 0-3 in SFN cell 0 or physical cell 1-1 in SFN cell 1. The coordinated set contains physical cell 0-3 and cell 3, or contains physical cell 1-1 and cell 3.

If 3-cell UL CoMP is enabled, the serving cell for UE 0 in Figure 2-6 will be cell 3, and the coordinated cells will be physical cell 0-3 in SFN cell 0 and physical cell 1-1 in SFN cell 1. The coordinated set contains the two physical cells and cell 3.

UL CoMP Between SFN Cells

The serving cell of UE 1 in Figure 2-6 is physical cell 1-1 in SFN cell 1, and the coordinated cell is physical cell 0-2 in SFN cell 0. The coordinated set of UE 1 contains the two physical cells.

2.5 Benefits

2-cell UL CoMP uses the antennas of two cells to receive signals from a UL CoMP UE. This type of UL CoMP offers higher gains than joint reception by the antennas of only one cell. If

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each cell has two receive antennas, a total of four antennas can be used to receive signals from a UL CoMP UE; by contrast, only two antennas can be used to receive a non-UL-CoMP UE. 3-cell UL CoMP uses the antennas of three cells to receive signals from a UL CoMP UE. This type of UL CoMP offers higher performance gains than 2-cell UL CoMP.

UL CoMP provides signal combining gains (including diversity gains and array gains) and interference mitigation gains. Generally, the gains increase with the number of receive antennas. For the sources of gains, see 2.5.1 Sources of Gains. For other details about gains, see Receiver Technology Feature Parameter Description.

UL CoMP increases the average uplink throughput for CEUs and cells. For data services, UL CoMP improves uplink modulation and coding schemes (MCSs) and reduces transmission delay. For voice over LTE (VoLTE) services, UL CoMP improves uplink MCSs, reduces bit error rates (BERs) in positions very far from the cell center, decreases packet loss rates, and reduces transmission delays, thereby improving voice quality and user experience.

2.5.1 Sources of Gains

UL CoMP selects appropriate UEs and receives signals from these UEs by using the antennas of multiple cells (instead of adding more receive antennas) to provide gains for UL CoMP UEs.

Depending on UE location, there are two sources of UL CoMP gains: l Signal combining gains (when a UE is located at the cell edge)

l Interference mitigation gains (when a UE is located anywhere within a cell)

The following table lists the coordination scopes where UL CoMP provides gains for UEs.

Table 2-3 Coordination scopes

Feature ID Coordination Scope for

Type-1 UE Coordination Scope forType-2 UE

Intra-BBP cells Intra-BBP cells except 4R cells (that is, cells each with four receive antennas) LOFD-070222

Intra-eNodeB UL CoMP Phase II

Intra-BBU cells Intra-BBP cells except 4R cells

Intra- or inter-BBU cells Intra-BBP cells except 4R cells

LOFD-081219 UL CoMP Based on Relaxed Backhaul

Intra- or inter-BBU cells NOTE

Note that cells that are connected through a relaxed backhaul network between different BBUs can be selected to serve as the coordinated cells for only type-1 UEs that support transmission time interval (TTI) bundling.

Intra-BBP cells except 4R cells (that is, cells each with four receive antennas)

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Feature ID Coordination Scope for

Type-1 UE Coordination Scope forType-2 UE

NOTE

LOFD-001066 is a prerequisite feature for LOFD-070222, LOFD-070223, and LOFD-081219. As LOFD-001066 supports BBP UL CoMP for type-2 UEs, the other three features also support intra-BBP UL CoMP for type-2 UEs.

The following describes the gains provided by LOFD-001066 Intra-eNodeB UL CoMP. Other UL CoMP features also provide these gains; the only difference is that these features provide higher gains in wider coordination scopes.

Signal Combining Gains

Signal combining gains are provided for UEs at the cell edge, as shown in Figure 2-7. For these UEs, the gains are obvious and the received signal quality is improved.

Figure 2-7 Signal combining gains

Interference Mitigation Gains

Interference mitigation gains are provided for UEs that experience interference from CEUs in neighboring cells. As shown in Figure 2-8, UE 0 experiences interference from UE 1 at the edge of an intra-frequency neighboring cell. The joint interference rejection combining (JIRC) algorithm selects UE 0 as a UL CoMP UE for interference mitigation. The interference mitigation gains are higher when the interference is higher.

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Figure 2-8 Interference mitigation gains

2.5.2 Areas Benefiting from UL CoMP

LOFD-001066 Intra-eNodeB UL CoMP and LOFD-070222 Intra-eNodeB UL CoMP

Phase II

The following figure represents a simulation of the areas benefiting from LOFD-001066 and LOFD-070222.

l The light blue parts are the areas in which intra- or inter-BBP UL CoMP can be performed for type-1 UEs.

l The dark blue parts are the areas in which intra-BBP UL CoMP can be performed for type-2 UEs.

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Figure 2-9 Areas benefiting from LOFD-001066 and LOFD-070222

NOTE

The dark red parts indicate the locations of antennas.

Areas Benefiting from Other UL CoMP Features

The following figure represents a simulation of the areas benefiting from other UL CoMP features.

l The light blue parts are the areas in which intra-BBP UL CoMP can be performed for type-1 UEs.

l The dark blue parts are the areas in which intra-BBP UL CoMP can be performed for type-2 UEs.

l The yellow and light red parts are the areas in which inter-BBP or inter-BBU UL CoMP can be performed. These areas are larger than those benefiting from LOFD-001066 Intra-eNodeB UL CoMP.

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Figure 2-10 Areas benefiting from other features

NOTE

The dark red parts indicate the locations of antennas.

2.5.3 Level of Gains

l LOFD-001066 Intra-eNodeB UL CoMP and LOFD-070222 Intra-eNodeB UL CoMP Phase II

– In macro-macro scenarios, the average cell throughput increases by 0% to 10% and the average CEU throughput increases by 0% to 200%.

– In macro-micro scenarios, the average uplink UE throughput increases by 0% to 250%.

l LOFD-070223 UL CoMP Based on Coordinated BBU

– In macro-macro scenarios, the average cell throughput increases by 0% to 20% and the average CEU throughput increases by 0% to 200%.

– In macro-micro scenarios, the average uplink UE throughput increases by 0% to 250%.

l LOFD-081219 UL CoMP Based on Relaxed Backhaul

The VoLTE packet loss rate decreases and therefore the coverage quality for VoLTE increases by 0 dB to 2 dB, provided that the voice quality does not deteriorate (for example, the mean opinion score [MOS] is 3).

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NOTE

The level of gains provided by UL CoMP depends on the following factors: l Proportion of UL CoMP UEs and proportion of UL CoMP PRBs

A small proportion of UL CoMP UEs or PRBs leads to lower UL CoMP gains.

l Environmental factors, such as interference, networking mode, user distribution, and user services l Other factors, such as the performance before UL CoMP is enabled and the RSRP difference

between the serving cell and coordinated cells of a single UE, according to admission tests in labs.

2.6 Evolution of UL CoMP

As UL CoMP evolves, the coordination scope becomes increasingly large. Figure 2-11 tracks the evolution of UL CoMP with Huawei eNodeBs.

Figure 2-11 Evolution of UL CoMP

The following describes the evolution of UL CoMP features. For a specific version, the UL CoMP capabilities inherited from earlier versions are not presented and only new capabilities are presented.

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Evolution of LOFD-001066 Intra-eNodeB UL CoMP

Table 2-4 Evolution of LOFD-001066 Intra-eNodeB UL CoMP eNodeB

Version BBP Model Number ofCells

Supported by a BBP

Receive

Mode Number ofCells in a Coordinated Set eRAN3.0 and later LBBPc, LBBPd1, LBBPd2, and LBBPd3 3 2R 2 eRAN6.0 and later LBBPd2 and LBBPd3 3 4R 2 LBBPd3 6 (3 cells on each frequency) 2R 2 eRAN7.0 and later LBBPd3 6 2R 2

UBBPd3 and UBBPd4 3 2R 2

UBBPd6 6 4R 2 eRAN8.1 LBBPd3 6 1R, 2R, or 1R+2R 3 LBBPd2, UBBPd3, and UBBPd4 3 1R, 2R, or 1R+2R 3

UBBPd5, UBBPd6, and UMDUa3 6 1R, 2R, or 1R+2R 3 LBBPd3, UBBPd5, UMDUa3 6 4R 2 LBBPd1 3 1R or 1R +2R 3 NOTE

xR+yR indicates that UL CoMP can be performed in cells with some in xR mode and the others in yR mode. x and y indicate the numbers of received antennas in different cells. xR+yR is used only when cells involved in UL CoMP have different numbers of receive antennas. For example, 1R+2R indicate that UL CoMP can be performed in cells with some in 1R mode and the others in 2R mode.

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Evolution of LOFD-070222 Intra-eNodeB UL CoMP Phase II

Table 2-5 Evolution of LOFD-070222 Intra-eNodeB UL CoMP Phase II eNodeB

Version BBP Model ReceiveMode Number ofCells in a

Coordinate d Set Scenario eRAN7.0 and later LBBPd2, LBBPd3, UBBPd3, UBBPd4, UBBPd5, and UBBPd6

2R 2 Inter-BBU

UL CoMP

LBBPd2, LBBPd3, UBBPd4, UBBPd5, and UBBPd6

4R 2

eRAN8.1 LBBPd2, LBBPd3, UBBPd3, UBBPd4, UBBPd5, and UBBPd6

1R, 2R, or 1R+2R

3

Evolution of LOFD-070223 UL CoMP Based on Coordinated BBU

Table 2-6 Evolution of LOFD-070223 UL CoMP Based on Coordinated BBU eNodeB

Version BBP Model ReceiveMode Number ofCells in a

Coordinate d Set Scenario eRAN7.0 and later LBBPd2, LBBPd3, UBBPd3, UBBPd4, UBBPd5, and UBBPd6

2R 2 Inter-BBU UL CoMP based on coordinated BBU LBBPd2, LBBPd3,

UBBPd4, UBBPd5, and UBBPd6

4R 2

eRAN8.1 LBBPd2, LBBPd3, UBBPd3, UBBPd4, UBBPd5, and UBBPd6

1R, 2R, or 1R+2R

3

LBBPd2, LBBPd3, UBBPd4, UBBPd5, and UBBPd6

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Evolution of LOFD-081219 UL CoMP Based on Relaxed Backhaul

Table 2-7 Evolution of LOFD-081219 UL CoMP Based on Relaxed Backhaul eNodeB

Version BBP Model Receive Mode Number ofCells in a

Coordinated Set Scenario eRAN8.1 LBBPd2 and LBBPd3 UBBPd3, UBBPd4, UBBPd5, and UBBPd6 2R 3 Inter-BBU UL CoMP based on relaxed backhaul

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3

Technical Description

This chapter describes the technical principles of UL CoMP, mainly the following key technologies:

l Selection of UL CoMP UEs and coordinated cells l Joint reception by multiple cells' antennas

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3.1 Basic Process

Figure 3-1 shows the basic process of UL CoMP.

Figure 3-1 Basic process of UL CoMP

The basic process is implemented through the following functions: l UL CoMP enabling

This function takes effect after the UL CoMP switch is turned on and cell-level parameters such as candidate coordinated cell parameters are configured. l Selection of UL CoMP UEs and coordinated cells

The eNodeB selects UL CoMP UEs and coordinated cells based on event A3

measurement reports, the number of physical resource blocks (PRBs) available for UL CoMP in the serving cell, and information about PRBs allocated to UEs.

l Joint reception by multiple cells' antennas

The physical layer combines the signals received by the antennas of the serving and coordinated cells of a UL CoMP UE based on information about the UE and coordinated cells.

Among these functions, the second and third are key. They are described in 3.2 Selection of UL CoMP UEs and Coordinated Cells and 3.3 Joint Reception by Multiple Cells' Antennas.

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3.2 Selection of UL CoMP UEs and Coordinated Cells

Selecting UL CoMP UEs for Macro-Macro or Micro-Micro UL CoMP

Figure 3-2 illustrates the differences in reference signal received power (RSRP) between the cells of an eNodeB to help understand the process of selecting UL CoMP UEs.

Figure 3-2 RSRP differences between cells

In the figure,

l The coordinates (0, 0) represent the antenna location.

l The horizontal and vertical axes represent the distances of UEs from the antenna (unit: m).

l Different colors indicate different absolute RSRP differences (unit: dB). RSRP difference is calculated as follows:

RSRP difference (dB) = RSRP received from a neighboring cell (dBm) – RSRP received in the serving cell (dBm)

The color ribbon on the right of the figure shows the mapping between RSRP differences and colors. For example, the deep blue at the bottom represents an RSRP difference of 0 dB. UEs in different areas can be selected as different types of UEs:

l UEs in the blue area can be selected as type-1 UEs.

l UEs in the red or yellow areas can be selected as type-2 UEs if they experience interference from type-1 UEs in the blue area.

Measuring RSRP

RSRP measurement used in UL CoMP is classified into two types: l Downlink RSRP measurement

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The UE measures the downlink RSRP (DL RSRP) values of the serving cell and

neighboring cells based on event A3 parameters configured on the eNodeB. The UE then reports the measurements to the eNodeB.

Event A3 in UL CoMP is reported periodically after it is triggered and reported for the first time. This reporting mode is called event-triggered periodic reporting mode. For details, see section 5.5.4.4 "Event A3 (Neighbour becomes offset better than serving)" in 3GPP TS 36.331 V9.9.0.

In macro-micro scenarios, there is a large difference in downlink CRS transmit power between macro and micro cells. Therefore, the difference in downlink RSRP must be corrected based on the difference in CRS transmit power so that appropriate UEs can be selected for UL CoMP.

l Uplink RSRP measurement

The serving cell and neighboring cells of a UE receive SRSs from the UE and measures the uplink RSRP (UL RSRP) values of these cells.

Selecting Type-1 UEs and Coordinated Cells for Macro-Macro or Micro-Micro UL

CoMP

After UL CoMP is enabled:

1. A UE sends UL CoMP A3 measurement reports to the eNodeB when reporting conditions are met.

2. The eNodeB sorts the reported neighboring cells by RSRP difference in descending order. Then, it selects coordinated cells for this UE from these neighboring cells in that order.

3. The eNodeB treats the reporting UE as a type-1 UE when the serving cell has sufficient PRBs for UL CoMP.

4. The UE sends UL CoMP A3 leaving reports to the eNodeB when leaving conditions are met.

5. The eNodeB no longer treats the UE as a UL CoMP UE when no coordinated cells can be selected from the reported neighboring cells.

NOTE

l The UE sends a UL CoMP A3 measurement report if the signal strength of a neighboring cell minus a specific UL CoMP A3 offset is greater than that of the serving cell. For details, see 3GPP TS 36.331.

l The UL CoMP A3 offset is specified by the CellUlCompAlgo.UlCompA3Offset or CellUlCompAlgo.UlCompA3OffsetForRelaxedBH parameter.

l All A3 parameters for UL CoMP except the A3 offset can be configured in the CellMcPara MO. In some unusual cases, immediately after a UE is handed over from an intra-frequency neighboring cell, the eNodeB treats this UE as a type-1 UE and treats this cell as a coordinated cell. The reason is that UL CoMP produces significant gains right after a coverage-based intra-frequency handover.

Selecting Type-2 UEs and Coordinated Cells for Macro-Macro or Micro-Micro UL

CoMP

The selection process is as follows:

1. Once a type-1 UE is identified, the serving cell and neighboring cells exchange the UE's PRB location information over the Uu interface.

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2. The eNodeB treats a UE in a neighboring cell as a type-2 UE when the following conditions are met:

– The PRB location of this UE overlaps that of the type-1 UE. – This neighboring cell has enough PRBs for UL CoMP.

3. The eNodeB treats the serving cell of the type-1 UE as a coordinated cell for the type-2 UE.

Selecting Type-1 UEs and Coordinated Cells for Macro-Micro UL CoMP

Selecting UL CoMP UEs and Coordinated Cells for Macro-Micro CoMP Based on Event A3

Before selecting neighboring micro cells as candidate coordinated cells for a UE in a macro cell, the eNodeB needs to correct the RSRP differences based on the transmit power of macro and micro cells. The correction formula is as follows:

RSRP difference after correction = RSRP difference before correction + (P_macro - P_micro) P_macro denotes the macro cell's transmit power (dBm). P_micro denotes the micro cell's transmit power (dBm).

The selection process is as follows:

2. The eNodeB creates a coordinated set for this UE: – The eNodeB corrects the RSRP differences.

– The eNodeB creates an A3-based neighboring cell list. The neighboring cells on this list must have RSRP differences greater than a specific UL CoMP A3 offset and come from the coordinated cell list of the serving cell.

– The eNodeB sorts the neighboring cells on the A3-based neighboring cell list by RSRP difference in descending order and selects coordinated cells for the UE from these neighboring cells in that order.

3. The eNodeB selects type-1 UEs in the same way as for macro-macro UL CoMP.

Selecting UL CoMP UEs and Coordinated Cells for Macro-Micro CoMP Based on Event A3 and SRS

1. Use parameters to manually create a list in which the neighboring micro cells of a macro cell require sounding reference signal (SRS) measurements. Alternatively, enable a macro cell to automatically generate such a list.

In automatic mode, if a neighboring micro cell has treated the macro cell as its

neighboring cell based on handover relationships, the macro cell adds this neighboring micro cell to the list.

2. The eNodeB creates a coordinated set for a UE:

– The eNodeB first creates an SRS-based neighboring cell list for a UE. The neighboring cells on this list meet the following conditions:

(1) The RSRP differences between these neighboring cells and the serving cell are greater than a specific UL CoMP A3 offset. Note that the RSRP values are calculated based on SRS measurements.

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– The eNodeB then sorts the neighboring cells from the combination of A3-based and SRS-based neighboring cell lists by RSRP difference in descending order. The eNodeB selects coordinated cells for this UE from these neighboring cells in that order to create a coordinated set for the UE.

3. When the serving cell of the UE has enough PRBs for UL CoMP and the A3- or SRS-based neighboring cell list of the UE is not empty, the eNodeB treats the UE as a type-1 UE.

4. When both the A3-based and SRS-based neighboring cell lists of the UE are empty, the eNodeB no longer treats the UE as a UL CoMP UE.

NOTE

In macro-micro scenarios, the difference in UL RSRP between macro and micro cells may be greater than the UL CoMP A3 offset, but the difference in DL RSRP between macro and micro cells may not be greater than the A3 offset and the UE may not send measurement reports. Therefore, SRS measurement is introduced for selecting coordinated cells for macro-micro UL CoMP.

When SRS measurement is used for macro-micro UL CoMP, see "Adding SRS Configurations in HetNet Scenarios" in "Parameter Optimization" for configuration. If the configuration is incorrect, UL CoMP based on UL RSRP cannot take effect.

Selecting Type-1 UEs and Coordinated Cells for UL CoMP in SFN Scenarios

For UL CoMP in SFN scenarios, the eNodeB selects type-1 UEs and coordinated cells based on both event A3 and SRS.

2. The eNodeB selects the neighboring cells with RSRP differences greater than a specified A3 offset from the coordinated cell list.

– If the neighboring cells are non-SFN cells, the eNodeB creates an A3-based neighboring cell list. The neighboring cells on this list must have RSRP differences greater than a specific UL CoMP A3 offset and come from the coordinated cell list of the serving cell.

– If the neighboring cells are SFN cells, the eNodeB creates an SRS-based neighboring cell list in addition to an A3-based neighboring cell list. The

neighboring cells on the SRS-based list are physical cells. They must have RSRP differences greater than a specific UL CoMP A3 offset and come from the coordinated cell list of the serving cell. The RSRP values are obtained based on SRS measurements.

3. The eNodeB sorts the neighboring cells from the combination of A3-based and SRS-based neighboring cell lists by RSRP difference in descending order and selects coordinated cells for the UE from these neighboring cells in that order.

NOTE

l If an SFN cell is the serving cell of a UE and its neighboring cells are non-SFN cells, these common cells can be selected as coordinated cells based on A3 measurement reports. The non-SFN cells do not require SRS configurations.

l The start SRS subframes must be different between an SFN cell and its neighboring cells (SFN or non-SFN cells). The eNodeB can treat a neighboring SFN cell as a coordinated cell for a UE only when the UE is allocated SRS resource in the start SRS subframe. It is recommended that SRS configurations be added according to the instructions in the "Parameter Optimization" sections. l The procedure for selecting type-2 UEs and coordinated cells in SFN scenarios is the same as that in

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3.3 Joint Reception by Multiple Cells' Antennas

Joint reception by multiple cells' antennas is similar to joint reception by a single cell's antennas.

Interference mitigation gains achieved in multiple cells are a main source of gains for UL CoMP. These gains can be achieved only after the license for LOFD-001012 UL Interference Rejection Combining is purchased and activated.

Both joint reception by a single cell's antennas and joint reception by multiple cells' antennas combine signals to improve performance.

The difference between them is that joint reception by multiple cells' antennas reuses existing antennas and radio frequency (RF) channels, without adding ones to cells. However, it also provides lower gains, as the signal power received in each cell varies.

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4

Related Features

4.1 Relationships Between UL CoMP Features

Relationships between UL CoMP features are as follows:

l LOFD-070222 Intra-eNodeB UL CoMP Phase II requires LOFD-001066 Intra-eNodeB UL CoMP.

l LOFD-070223 UL CoMP Based on Coordinated BBU requires LOFD-070222 Intra-eNodeB UL CoMP Phase II.

l LOFD-081219 UL CoMP Based on Relaxed Backhaul requires LOFD-070222 Intra-eNodeB UL CoMP Phase II.

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4.2 Features Related to LOFD-001066 Intra-eNodeB UL

CoMP

Prerequisite Features

The prerequisite feature is LOFD-001012 UL Interference Rejection Combining. This feature provides interference mitigation gains, a main source of gains for UL CoMP.

Mutually Exclusive Features

High Speed Mobility and Ultra High Speed Mobility

Rapid changes in channel quality or delay in high or ultra-high speed movement scenarios have a significant impact on joint reception and signal combining. Therefore, when

LOFD-001007 High Speed Mobility or LOFD-001008 Ultra High Speed Mobility is enabled, the eNodeB disables UL CoMP, regardless of whether the UL CoMP switch

(CellAlgoSwitch.UplinkCompSwitch) is turned on.

Frequency Hopping

When frequency hopping is enabled (that is, when the CellUlschAlgo.UlHoppingType parameter is not set to Hopping_OFF), the eNodeB automatically disables UL CoMP, regardless of whether the UL CoMP switch is turned on.

Remote Radio Unit

When the distances between remote radio units (RRUs) and the connected BBU are greater than 20 km, the transmission delays from the RRUs to the BBP cannot meet the UL CoMP requirements. In such a case, you need to turn off the UL CoMP switch.

NOTICE

The distances between RRUs and the connected BBU must be less than or equal to 20 km.

Multi-RRU Cell

If the Cell.MultiRruCellMode parameter is set to DIGITAL_COMBINATION, the eNodeB automatically disables UL CoMP.

SFN Based on Coordinated BBU

l LOFD-081208 Inter-eNodeB SFN Based on Coordinated BBU

l LOFD-081209 Inter-eNodeB adaptive SFN/SDMA Based on Coordinated BBU UL CoMP is not compatible with these SFN features based on coordinated BBU.

Impacted Features

UL CoMP uses the antennas of multiple cells to receive signals over the PUSCH. Therefore, UL CoMP benefits all PUSCH-related features without affecting the applications of these features, for example:

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l Transmission time interval (TTI) bundling l Voice over IP (VoIP)

l Radio access network (RAN) sharing

MU-MIMO

The following multi-user multiple-input multiple-output (MU-MIMO) features are impacted: l LOFD-001002 UL 2x2 MU-MIMO

l LOFD-001058 UL 2x4 MU-MIMO

For a UE, UL CoMP and MU-MIMO cannot take effect simultaneously although they can be enabled at the same time. UL CoMP for type-1 UEs has the highest priority, MU-MIMO the second, and UL CoMP for type-2 UEs the third.

UL ICIC

The following uplink inter-cell interference coordination (UL ICIC) features are impacted: l LBFD-00202202 Uplink Static Inter-Cell Interference Coordination

l LOFD-00101402 Uplink Dynamic Inter-Cell Interference Coordination

UL ICIC allocates different frequency bands to CEUs to reduce inter-cell interference. Therefore, when UL ICIC is enabled, UL CoMP cannot provide high interference mitigation gains for CEUs. However, the total gains provided by UL ICIC and UL CoMP are higher than the gains provided by only UL ICIC or UL CoMP.

Carrier Aggregation

The following CA features are impacted: l LAOFD-001001 LTE-A Introduction

l LAOFD-001002 Carrier Aggregation for Downlink 2CC in 40MHz l LAOFD-070201 Flexible CA from Multiple Carriers

l LAOFD-080202 Carrier Aggregation for Uplink 2CC [Trial]

For a 4R cell, these carrier aggregation (CA) features and UL CoMP can be enabled simultaneously. For a UE, however, these CA features and UL CoMP cannot take effect simultaneously, and the CA features will take precedence over UL CoMP.

If LAOFD-080202 Carrier Aggregation for Uplink 2CC [Trial] is enabled, the uplink SCell of a UE will not be selected for UL CoMP.

SFN

The following SFN features are impacted: l LOFD-003029 SFN

l LOFD-070205 Adaptive SFN/SDMA

When UL CoMP works with SFN and a local cell has neighboring SFN cells, the eNodeB selects UL CoMP UEs and coordinated cells based on SRS measurements. SRS resources in SFN cells are preferentially allocated to UEs for SFN-related measurement so that the eNodeB can select target RF modules and determine UE attributes. If there are too many UEs in SFN cells, SRS resources may be insufficient and the number of UL CoMP UEs may be less than that in UL CoMP between non-SFN cells.

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The impacted feature is LOFD-081206 Intra-eNodeB Coordinated Uplink AMC.

The UL CoMP switch settings for all cells in a coordinated adaptive modulation and coding (CAMC) set must be the same. If the UL CoMP switch settings are changed for some of the cells, the CAMC set will change, which affects CAMC performance.

When UL CoMP is disabled, the CAMC A3 offset is determined by the

CellUlSchAlgo.UlCamcDlRsrpOffset parameter setting. When UL CoMP is enabled, the

CAMC A3 offset is equal to the UL CoMP A3 offset and the

CellUlSchAlgo.UlCamcDlRsrpOffset parameter does not take effect. If the UL CoMP A3

offset is different from the CAMC A3 offset, the interference measurement set will change, which affects CAMC performance. Therefore, it is recommended that the UL CoMP A3 offset be equal to the CAMC A3 offset.

Other Features

The other impacted features include A3-related features, which share all A3 parameters except the A3 offset with UL CoMP. The A3-related features include ICIC, adaptive ICIC (aICIC), enhanced (eICIC), and GSM and LTE FDD Dynamic Spectrum Sharing (GLDSS). The shared A3 parameters are as follows:

l CellMcPara.Hysteresis l CellMcPara.TriggerQuantity l CellMcPara.ReportQuantity l CellMcPara.TimeToTrigger l CellMcPara.ReportInterval l CellMcPara.ReportAmount

Any changes in the values of these parameters affect both the A3-related features and UL CoMP.

4.3 Features Related to LOFD-070222 Intra-eNodeB UL

CoMP Phase II

Prerequisite Features

LOFD-070222 Intra-eNodeB UL CoMP Phase II requires LOFD-001066 Intra-eNodeB UL CoMP and takes effect only when both features are enabled.

The other prerequisite features are the same as those of LOFD-001066 Intra-eNodeB UL CoMP.

Mutually Exclusive Features

This feature is mutually exclusive with MRFD-090202 GSM and LTE FDD Dynamic Spectrum Sharing(LTE FDD).

The other features mutually exclusive with this feature are the same as those for LOFD-001066 Intra-eNodeB UL CoMP.

Impacted Features

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l LAOFD-001001 LTE-A Introduction

For a 4R cell, these CA features and UL CoMP can be enabled simultaneously. For a UE, however, these CA features and UL CoMP cannot take effect simultaneously, and the CA features will take precedence over UL CoMP.

LOFD-070222 Intra-eNodeB UL CoMP Phase II shares the intra-BBU inter-BBP

transmission bandwidth with these CA features. When the transmission bandwidth is limited, any feature that fails to obtain bandwidth resources cannot take effect.

The other impacted features are the same as those of LOFD-001066 Intra-eNodeB UL CoMP.

4.4 Features Related to LOFD-070223 UL CoMP based on

Coordinated BBU

Prerequisite Features

The prerequisite features include LOFD-001066 Intra-eNodeB UL CoMP and LOFD-070222 Intra-eNodeB UL CoMP Phase II. LOFD-070223 UL CoMP Based on Coordinated BBU takes effect only when this feature and the prerequisite features are all enabled.

Mutually Exclusive Features

The features mutually exclusive with this feature are the same as those for LOFD-070222 Intra-eNodeB UL CoMP Phase II.

Impacted Features

For a 4R cell, the CA feature and UL CoMP can be enabled simultaneously. For a UE, however, these features cannot take effect simultaneously, and the CA feature will take precedence over UL CoMP.

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This feature shares inter-BBU transmission bandwidth with LOFD-070223 UL CoMP Based on Coordinated BBU. When the transmission bandwidth is limited, any feature that fails to obtain bandwidth resources cannot take effect.

The other impacted features are the same as those of LOFD-001066 Intra-eNodeB UL CoMP.

4.5 Features Related to LOFD-081219 UL CoMP Based on

Relaxed Backhaul

Prerequisite Features

LOFD-081219 UL CoMP Based on Relaxed Backhaul requires the following features: l LOFD-001066 Intra-eNodeB UL CoMP

l LOFD-070222 Intra-eNodeB UL CoMP Phase II l LOFD-001048 TTI Bundling

NOTE

LOFD-001048 TTI bundling uses the retransmission interval 16 TTIs in the hybrid automatic repeat request (HARQ) mechanism to better adapt to transmission delays induced by relaxed backhaul networks.

LOFD-081219 UL CoMP Based on Relaxed Backhaul takes effect only when this feature and all its prerequisite features are enabled.

Mutually Exclusive Features

The features mutually exclusive with this feature are the same as those for LOFD-070223 UL CoMP Based on Coordinated BBU.

Impacted Features

l LAOFD-080202 Carrier Aggregation for Uplink 2CC [Trial] l LAOFD-080201 Inter-eNodeB CA based on Relaxed backhaul

For a cell, these CA features can be enabled together with LOFD-081219 UL CoMP Based on Relaxed Backhaul. For a CA UE, cells that are connected through a relaxed backhaul network are not selected as coordinated cells for UL CoMP.

eX2 QoS Handling Mechanism

When the eNodeB detects that transport queues on an eX2 interface are congested, it triggers back pressure on traffic related to inter-BBU UL CoMP based on relaxed backhaul on the eX2 interface in question or it triggers a removal of coordinated cells connected through the eX2

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interface. As the number of coordinated cells decreases, the data rates of UL CoMP UEs may also decrease.

When the eNodeB detects that the congestion is relieved, it either stops the back pressure or restores the coordinated cells.

When the eNodeB detects that the transport resource is overloaded, it triggers a removal of the eX2 interface and the coordinated cells connected through the eX2 interface.

SFN

The following SFN features are impacted: l LOFD 003029 SFN

l LOFD-070205 Adaptive SFN/SDMA

These SFN features can be enabled together with LOFD-081219 UL CoMP Based on Relaxed Backhaul. However, UL CoMP cannot be performed in an SFN cell and another cell that are connected through a relaxed backhaul network.

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5

Network Impact

5.1 LOFD-001066 Intra-eNodeB UL CoMP

System Capacity

This feature effectively increases the average uplink throughput for UL CoMP UEs and further increases the average uplink throughput for both CEUs and cells.

Network Performance

This feature improves MCSs for UL CoMP UEs, reduces the number of transport blocks (TBs) erroneously transmitted in the initial uplink transmission, and effectively increases the average uplink throughput for both CEUs and cells. As the average CEU uplink throughput increases, this feature enhances uplink coverage.

In long inter-RRU distance scenarios (for example, in suburban and rural areas), the interference from neighboring cells is weak and therefore this feature does not provide high interference mitigation gains.

5.2 LOFD-070222 Intra-eNodeB UL CoMP Phase II

System Capacity

This feature provides a larger coordination scope (from intra-BBP cells to intra-BBU inter-BBP cells) than that provided by LOFD-001066 Intra-eNodeB UL CoMP. This results in an increased average uplink throughput for both intra-BBU inter-BBP cells and CEUs.

Network Performance

This feature has the same impacts on network performance as LOFD-001066 Intra-eNodeB UL CoMP.

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5.3 LOFD-070223 UL CoMP based on Coordinated BBU

System Capacity

This feature increases the average uplink throughput for both inter-BBU cells and CEUs. This feature expands coordination scope. It supports 3-cell UL CoMP in centralized,

distributed, or centralized+distributed Cloud BB scenarios and therefore further increases the average uplink throughput for both cells and CEUs.

Network Performance

This feature has the same impacts on network performance as LOFD-001066 Intra-eNodeB UL CoMP.

5.4 LOFD-081219 UL CoMP Based on Relaxed Backhaul

System Capacity

This feature can be used when transmission performance is affected by transmission delay and bandwidth. This feature has no impact on system capacity.

Network Performance

Together with TTI bundling (which is mainly used for voice services), this feature reduces the number of uplink TBs erroneously transmitted during the initial transmission and decreases the packet loss rate, thereby improving voice quality.

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6

Engineering Guidelines for LOFD-001066

Intra-eNodeB UL CoMP

6.1 When to Use LOFD-001066 Intra-eNodeB UL CoMP

When the inter-RRU distance is not greater than 1000 m in urban areas, LOFD-001066 Intra-eNodeB UL CoMP is recommended because this feature effectively increases the average uplink throughput for intra-BBP cells and CEUs. In addition:

l In suburban, rural, and other areas where the inter-RRU distance is large, this feature is not recommended.

l You are advised to optimize parameter settings by referring to the "Parameter Optimization" section to reduce the impact of signaling processing for event A3 measurement reporting in one of the following situations:

– The uplink or downlink PRB usage is greater than 90%. – The control channel element (CCE) usage is greater than 80%. – The central processing unit (CPU) usage is greater than 80%.

l If there is intermodulation interference, solve this problem before using this feature. l If the difference in cell-specific reference signal (CRS) transmit power between macro

and micro cells is greater than or equal to 6 dB, it is recommended that macro-micro UL CoMP based on SRS measurement be used.

l When both SFN and UL CoMP are enabled, the start SRS subframe of the SFN cell must be different from those of its neighboring cells (common or SFN cells). The eNodeB can select a neighboring SFN cell to serve as a coordinated cell for a UE only when the UE is allocated SRS resource in the start SRS subframe.

6.2 Required Information

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6.3 Planning

RF Planning

N/A

Network Planning

For intra-frequency cells covered by antennas installed on the same pole or tower, it is recommended that these cells be set up on the same BBP.

NOTE

When the BBP is restarted or reset, the cells are reestablished. The deployment information for these cells may change and the coordinated cell lists may also change. These changes will affect the performance of UL CoMP.

Hardware Planning

For details about the requirements for the BBP models in different UL CoMP scenarios, see

2.6 Evolution of UL CoMP.

6.4 Deployment

6.4.1 Requirements

Operating Environment

The following table describes the requirements for the operating environment.

Table 6-1 Requirements for the operating environment Information to

Be Collected Requirements

eNodeB type Macro eNodeBs

RRU model If the LBBPc is used and the cells are configured for UL CoMP, the RRUs must have the same model.

Macro-micro and micro-micro UL CoMP in eRAN8.1 allows micro cells to be low power nodes (LPNs), for example, RRU3220E.

UL CoMP(eRAN8.1_03)

UL CoMP Feature Parameter

Description

Huawei Technologies Co., Ltd.

Contents

1 About This Document... 1

2 Overview... 9

3 Technical Description...28

4 Related Features...35

5 Network Impact... 42

6 Engineering Guidelines for LOFD-001066 Intra-eNodeB UL CoMP... 44

7 Engineering Guidelines for LOFD-070222 Intra-eNodeB UL CoMP Phase II... 76

8 Engineering Guidelines for LOFD-070223 UL CoMP based on Coordinated BBU... 96

10 Parameters...133

11 Counters... 157

12 Glossary...162

13 Reference Documents... 163

1

About This Document

1.1 Scope

1.2 Intended Audience

1.3 Change History

eRAN8.1 03 (2015-08-31)

eRAN8.1 02 (2015-04-30)

eRAN8.1 01 (2015-03-23)

eRAN8.1 Draft A (2015-01-15)

1.4 Differences Between eNodeB Types

Feature Support by Macro, Micro, and LampSite eNodeBs

Function Implementation in Macro, Micro, and LampSite eNodeBs

2

Overview

2.1 Background

2.2 Introduction

UL CoMP Classification

LOFD-001066 Intra-eNodeB UL CoMP

LOFD-070222 Intra-eNodeB UL CoMP Phase II

LOFD-070223 UL CoMP based on Coordinated BBU

LOFD-081219 UL CoMP Based on Relaxed Backhaul

2.3 Related Concepts

UL CoMP UE

2-Cell UL CoMP

3-Cell UL CoMP

Coordinated Cell

Coordinated Set

Coordinated Cell List

Connection Set

Example

2.4.1 LOFD-001066 Intra-eNodeB UL CoMP

2.4.2 LOFD-070222 Intra-eNodeB UL CoMP Phase II

2.4.3 LOFD-070223 UL CoMP based on Coordinated BBU

2.4.4 LOFD-081219 UL CoMP Based on Relaxed Backhaul

2.4.5 UL CoMP in SFN Scenarios

UL CoMP Between SFN and Non-SFN Cells

UL CoMP Between SFN Cells

2.5 Benefits

2.5.1 Sources of Gains

Signal Combining Gains

Interference Mitigation Gains

2.5.2 Areas Benefiting from UL CoMP

LOFD-001066 Intra-eNodeB UL CoMP and LOFD-070222 Intra-eNodeB UL CoMP

Phase II

Areas Benefiting from Other UL CoMP Features

2.5.3 Level of Gains

2.6 Evolution of UL CoMP

Evolution of LOFD-001066 Intra-eNodeB UL CoMP

Evolution of LOFD-070222 Intra-eNodeB UL CoMP Phase II

Evolution of LOFD-070223 UL CoMP Based on Coordinated BBU

Evolution of LOFD-081219 UL CoMP Based on Relaxed Backhaul

3

Technical Description

3.1 Basic Process

3.2 Selection of UL CoMP UEs and Coordinated Cells

Selecting UL CoMP UEs for Macro-Macro or Micro-Micro UL CoMP

Measuring RSRP

Selecting Type-1 UEs and Coordinated Cells for Macro-Macro or Micro-Micro UL

CoMP

Selecting Type-2 UEs and Coordinated Cells for Macro-Macro or Micro-Micro UL

CoMP

Selecting Type-1 UEs and Coordinated Cells for Macro-Micro UL CoMP

Selecting Type-1 UEs and Coordinated Cells for UL CoMP in SFN Scenarios