Interference Rejection Combining

Interference Rejection Combining

USER DESCRIPTION

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Copyright

Ericsson AB 2011. All rights reserved. No part of this document may bereproduced in any form without the written permission of the copyright owner.

Disclaimer

The contents of this document are subject to revision without notice due tocontinued progress in methodology, design and manufacturing. Ericsson shallhave no liability for any error or damage of any kind resulting from the useof this document.

Trademark List

All trademarks mentioned herein are the property of their respective owners.These are shown in the document Trademark Information.

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Contents

Contents

1 Introduction 11.1 Basic Characteristics 11.2 Benefits 11.3 Additional Information 1

2 Feature Operation 32.1 Network Requirements 32.2 High Level Description 32.3 Interference Rejection Combining Process Steps 33 Parameters 53.1 Introduced Parameters 53.2 Affected Parameters 5

4 Network Impact 74.1 Capacity 74.2 Coverage 7

5 Associated Features and 95.1 Prerequisite Features 95.2 Affected Features 95.3 Related Features 95.4 Affected System Functions 9

6 Performance 116.1 KPIs 116.2 Counters 116.3 Events 11

7 O&M Information 13

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Introduction

1 Introduction

This document describes the Interference Rejection Combining feature and itsmain benefits and impacts in the LTE RAN.

This document describes the feature .

1.1 Basic CharacteristicsThis section describes the basic characteristics of the feature.

Feature Identity FAJ 221 0978, Interference Rejection CombiningReplaces: N/A

Dependencies

This feature has no prerequisite features.

This feature affects no other features.

1.2 BenefitsThis section describes the benefits of this feature.

Interference Rejection Combining (IRC) is a method for antenna combining andis superior to Maximum Ratio Combining (MRC) when suppressing on receivedsignals. IRC uses correlations in the spatial domain (between antennas) andin the frequency domain to suppress interfering signals from other cells orin-band external interferers. IRC improves the Block Error Rate (BLER) onthe Physical Uplink Shared Channel (PUSCH) and Physical Uplink ControlChannel (PUCCH) compared to MRC and improves uplink throughput in uplinkinterference limited systems. The use of IRC on uplink channels does notrequire any additional User Equipment (UE) support.

1.3 Additional InformationMore information about this feature and related topics can be found in thefollowing documentation:

3GPP TS 36.211

3GPP TS 36.212

3GPP TS 36.213

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Applications of Antenna Arrays to Mobile Communications, Part I:Performance Improvement, Feasibility, and System Considerations

Application of Antenna Arrays to Mobile Communications, Part II:Beam-Forming and Direction-of-Arrival Considerations

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Feature Operation

2 Feature Operation

This section describes the Interference Rejection Combining feature in moredetail, including network configuration requirements and operation flows.

2.1 Network RequirementsThe following must be fulfilled at feature activation:

At least two receive antennas must be installed for the cells on the RBS.

2.2 High Level DescriptionThe Interference Rejection Combining feature is a form of antenna combiningthat is superior to MRC in interference limited systems.

This licensed feature enables the operator to improve the suppression ofinter-cell interference by using Interference Rejection Combining. When thefeature is enabled, the RBS will decide to use the Interference RejectionCombining feature instead of MRC in interference limited situations.

2.3 Interference Rejection Combining Process StepsThis section describes the main process steps for the feature flow.

2.3.1 Interference Suppression

Figure 1 shows how the Interference Rejection Combining feature can be usedin the antenna combiner rather than MRC to improve interference suppression.

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L0000494A

Antennacombiner Equalizer Decoder

Figure 1 IRC As Antenna Combiner Rather than MRC

The Interference Rejection Combining feature maximizes the Signal toInterference and Noise Ratio (SINR) of the combined signal by minimizing thenoise and interference at the antenna combiner output while preserving thesignal. It can be seen as weighting down the signal in the directions of theinterferers, so that they do not corrupt the signal from the desired user.

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Parameters

3 Parameters

This section describes the parameters introduced by the Interference RejectionCombining feature and parameters affected by activating the feature.

3.1 Introduced ParametersTable 1 describes the parameters introduced by the feature.

Table 1 Introduced ParametersParameter DescriptionfeatureStateIrc Activates or deactivates the Interference Rejection Combining

licensed feature

licenseStateIrc Indicates the status of the Interference Rejection Combining,licensed feature: ENABLED or DISABLED

serviceStateIrc Indicates whether the Interference Rejection Combining featureis operable or inoperable, and whether the feature is providingservice

3.2 Affected ParametersThe implementation of this feature affects no parameters.

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Network Impact

4 Network Impact

This section describes how the Interference Rejection Combining featureimpacts the network functions and capabilities.

4.1 CapacityThis section provides information on the impact of the feature on networkcapacity.

This feature will increase the uplink capacity of the system.

4.2 CoverageThis section provides information on the impact of the feature on networkcoverage.

This feature may increase the coverage active UE in uplink interference limitedenvironments.

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Associated Features and

5 Associated Features and

This section describes how the Interference Rejection Combining featureaffects other features and functions.

5.1 Prerequisite FeaturesThis feature has no prerequisite features.

5.2 Affected FeaturesThis feature affects no other feature.

5.3 Related FeaturesThis feature is not related to any other feature.

5.4 Affected System FunctionsThis feature affects no system functions.

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Performance

6 Performance

This section describes performance indicators, counters, and events associatedwith the Interference Rejection Combining feature.

6.1 KPIsThis feature has no associated Key Performance Indicators (KPIs).

6.2 CountersThis feature has no directly associated counters.

6.3 EventsThis feature has no associated events.

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O&M Information

7 O&M Information

This section provides Operation and Maintenance (O&M) information for theInterference Rejection Combining feature.Activating the Interference Rejection Combining feature requires thatthe corresponding license is installed. For more information on handlinglicenses, see the document License Management. Interference RejectionCombining feature is activated by setting thefeatureStateIrc parameterto ACTIVATED. The operation state of the Interference Rejection Combiningfeature can be checked with the parameter serviceStateIrc.

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toc1 Introduction1.1 Basic CharacteristicsDependencies1.2 Benefits1.3 Additional Information

2 Feature Operation2.1 Network Requirements2.2 High Level Description2.3 Interference Rejection Combining Process Steps2.3.1 Interference Suppression

3 Parameters3.1 Introduced Parameters3.2 Affected Parameters

4 Network Impact4.1 Capacity4.2 Coverage

5 Associated Features and 5.1 Prerequisite Features5.2 Affected Features5.3 Related Features5.4 Affected System Functions

6 Performance 6.1 KPIs6.2 Counters6.3 Events

7 O&M Information

Documents

Interference Rejection Combining