Consolidated Power Headroom Reporting in LTE-Advanced Carrier Aggregation

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Solution Overview

Problem

In carrier aggregation scenarios of Advanced Long Term Evolution (LTE-Advanced) technology, user equipment (UE) needs to report power headroom (PHR) to multiple uplink component carriers, which consumes significant resources and is inefficient.

Innovation Solution

The UE encapsulates both UE-specific and uplink component carrier (UL CC)-specific PHR information in a single report, using a preset order and indication bits to indicate which PHRs are included, allowing the eNB to extract and analyze the necessary PHR information efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the UE reports PHR for each uplink component carrier separately, then the eNB can obtain complete power headroom information for resource allocation, but the resource overhead and reporting efficiency deteriorate significantly

Engineering Contradiction:
ImprovePHR information completenessVSAvoidreporting resource overhead
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent merges multiple separate PHR reports for different uplink component carriers into a single consolidated PHR message. The UE reports PHR for all configured uplink component carriers (including primary and secondary carriers) in one unified structure, eliminating the need for multiple separate reporting transactions and significantly reducing overhead while maintaining complete information.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The PHR message structure is designed to serve multiple functions simultaneously - it can indicate PHR status for different carrier types (primary uplink carrier, secondary uplink carriers), different PHR types (Type1 for PUSCH, Type2 for PUCCH), and various reporting conditions (periodic, aperiodic, triggered) within a single universal framework.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If the UE reports PHR for all configured uplink component carriers, then the eNB has complete information for uplink resource allocation, but the reporting time and complexity increase

Engineering Contradiction:
Improveuplink resource allocation accuracyVSAvoidPHR reporting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The PHR message is segmented into multiple fields and indicators that can be processed in a structured manner. The message includes indicators for different carrier types, PHR types, and reporting conditions, allowing the eNB to efficiently parse and process only the relevant information needed for current resource allocation decisions without processing the entire message sequentially.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The UE determines and prepares the PHR content in advance based on configured parameters and current transmission conditions. The UE calculates power headroom values and determines which carriers need reporting before actually transmitting the PHR message, optimizing the reporting process time.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If the UE uses separate PHR reporting for each carrier, then carrier-specific power control is precise, but the system complexity and processing burden increase

Engineering Contradiction:
Improvecarrier-specific power headroom measurementVSAvoidPHR reporting system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

While maintaining a unified PHR structure, the patent incorporates local-specific indicators and fields for different carrier types and PHR types. Each carrier's PHR information is preserved with its specific characteristics (e.g., distinguishing between primary and secondary carriers, Type1 and Type2 PHR), allowing precise carrier-specific power control while using a common reporting framework.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2472942B1Method and system for reporting power headroom report (PHR) in carrier aggregation scene
Publication Date: 2015.03.18 ZTE CORP
  • EP2472942B1 patent drawingFigure 1
  • EP2472942B1 patent drawingFigure 2~3
  • EP2472942B1 patent drawingFigure 4

AI summary

A method and system for reporting PHR in carrier aggregation scenarios are disclosed in the present invention. The method includes: UE encapsulating UE specific PH and/or UL CC specific PH that need to be reported into a same PHR according to a preset order, and meanwhile encapsulating indication information that indicates whether the UE specific PH and each UL CC specific PH are reported or not into the PHR, then sending the PHR to eNB; after receiving the PHR, the eNB analyzing the PHR to obtain the PH and indication information in the PHR, determining the type and quantity of the UE specific PH and/or each UL CC specific PH reported in the PHR according to the indication information and scene configured by eNB for the UE, and then extracting the UE specific PH and/or each UL CC specific PH from the PHR in combination with the preset order.