Power Headroom Reporting in Asynchronous Wireless Connectivity

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Solution Overview

Problem

In multiple connectivity wireless communications, existing techniques are unclear about reporting power headroom in scenarios where subframes for different cell groups are asynchronous or use different frame structures, leading to undefined or incomplete power headroom reporting.

Innovation Solution

A method and apparatus for a wireless device to determine and report power headroom in multiple connectivity scenarios by configuring reporting based on the subframe type, allowing for virtual or actual power headroom reporting, even when subframes are not aligned or use different configurations, by signaling parameters from the cells involved.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If power headroom reporting is configured for multiple cells or cell groups with different frame structures and subframe configurations, then the system supports multiple connectivity wireless communications with diverse frame structures (FDD, TDD, asynchronous timing), but the reporting becomes undefined or incomplete when subframes for different cell groups are misaligned

Engineering Contradiction:
Improvesupport for multiple connectivity with different frame structuresVSAvoidpower headroom reporting completeness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic determination of reporting configuration based on the type of subframe. The wireless device checks whether the subframe is an uplink subframe for the second cell group, and if not, it dynamically selects between reporting actual power headroom, virtual power headroom, or no report at all. This dynamic adaptation resolves the contradiction by making the reporting mechanism flexible enough to handle misaligned subframes while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the wireless device reports actual power headroom for one cell group, then accurate power information is provided for that cell group, but only virtual power headroom reporting is possible for another cell group with non-uplink subframes

Engineering Contradiction:
Improvepower headroom accuracyVSAvoidpower headroom reporting completeness
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent applies local quality by allowing different reporting modes for different cell groups based on their specific subframe configurations. For cell groups with uplink subframes, actual power headroom is reported with high precision. For cell groups with non-uplink subframes, virtual power headroom or selective reporting is used. This localized adaptation ensures measurement precision where possible while minimizing information loss overall.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If power headroom reporting is performed in all subframes, then complete power information is available, but the reporting becomes undefined when subframes are downlink or special subframes for certain cell groups

Engineering Contradiction:
Improvepower headroom reporting volumeVSAvoidreporting configuration simplicity
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The patent implements partial action by selectively reporting power headroom based on subframe type. Instead of reporting in all subframes regardless of type, the device performs reporting only when appropriate (actual power headroom for uplink subframes, virtual or selective for non-uplink subframes). This partial approach maintains sufficient reporting volume while simplifying the configuration and avoiding undefined states.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3152966B1Techniques for reporting power headroom in multiple connectivity wireless communications
Publication Date: 2020.08.19 QUALCOMM INC
  • EP3152966B1 patent drawingFigure 1
  • EP3152966B1 patent drawingFigure 2
  • EP3152966B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure relate to reporting power headroom in wireless communications. A device can establish a first connection served by at least a first cell, and establish a second connection served by at least a second cell in multiple connectivity/carrier aggregation. The device can then determine to report a first power headroom in a first uplink subframe of the first cell in the first cell. The device can also determine a reporting configuration for possibly reporting a second power headroom based on a second subframe of the second cell as a companion report with the first power headroom when a type of the second subframe of the second cell is not an uplink subframe.