Selective Power Headroom Report Transmission in 5G UEs

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Solution Overview

Problem

Existing wireless communication systems, particularly in 5G, face inefficiencies in power headroom reporting (PHR) due to inadequate management of pathloss changes and resource allocation, leading to suboptimal network performance and increased latency.

Innovation Solution

A method for selective transmission of power headroom reports (PHRs) based on pathloss estimates and resource set configurations, allowing UEs to manage power control more effectively by maintaining optimal pathloss references and reducing unnecessary PHR transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If power headroom reports are transmitted frequently to maintain accurate power control, then power control accuracy is improved, but signaling overhead and latency increase

Engineering Contradiction:
Improvepower control accuracyVSAvoidlatency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent changes the parameter of PHR transmission from periodic/frequent to event-triggered based on pathloss conditions. The UE monitors pathloss changes and only transmits PHR when pathloss varies beyond a threshold, transforming the transmission pattern from time-driven to condition-driven, thereby reducing unnecessary transmissions while maintaining accuracy when needed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The UE autonomously determines when to transmit PHR based on locally monitored pathloss conditions without requiring network scheduling commands. The device self-manages the reporting process by comparing current pathloss against stored reference values and transmitting only when the difference exceeds the threshold, eliminating waiting time for network coordination.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If power headroom reports are transmitted frequently to maintain accurate power control, then power control accuracy is improved, but signaling overhead increases

Engineering Contradiction:
Improvepower control accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent transforms the PHR transmission parameter from fixed periodic intervals to variable event-triggered moments based on pathloss changes. This parameter change ensures PHR is transmitted only when power conditions actually change, eliminating redundant signaling while maintaining necessary information flow for accurate power control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts the essential triggering condition (pathloss change exceeding threshold) from the PHR transmission process. By taking out only the necessary transmissions based on actual power condition changes, the system removes unnecessary signaling overhead while preserving the critical information needed for power control adjustments.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If multiple pathloss references are maintained for different resource sets, then power control adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvepower control adaptabilityVSAvoidcomplexity of maintaining pathloss estimates
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by maintaining different pathloss reference values for different uplink resource sets (e.g., different SRS resources, PUCCH, PUSCH). Each resource set has its own dedicated pathloss reference, allowing localized optimization of power control for each resource type without requiring complex global coordination, thereby managing complexity through structured local management.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4104540B1Selective transmission of power headroom reports
Publication Date: 2025.08.27 QUALCOMM INC
  • EP4104540B1 patent drawingFigure 1
  • EP4104540B1 patent drawingFigure 2A
  • EP4104540B1 patent drawingFigure 2B

AI summary

Disclosed are techniques for wireless communication. In an aspect, a UE determines determining whether to perform a power headroom report (PHR) function for a pathloss reference signal (PL-RS). Based on the determination, the UE performs a PHR function or one or more pathloss measurements for the PL-RS based on the determination. In some aspects, the determination is based on a PL-RS type or cell type associated with the PL-RS. In other aspects, the determination is based on an indication (e.g., explicit or implicit indication) associated with the PL-RS that is received from a serving cell of the UE.