Wireless Device Transmit Power Control for RF Exposure Compliance

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Solution Overview

Problem

Wireless communication devices face challenges in maintaining effective RF exposure compliance while ensuring optimal transmission power levels, leading to potential energy wastage and reduced communication performance, especially at the edge of cells where higher power levels are needed for network connectivity.

Innovation Solution

Implementing a method where wireless devices determine an energy budget associated with an RF exposure limit for a time window, calculating energy usage for each transmission occasion, and adjusting transmit power to ensure compliance without exceeding the energy budget, thereby optimizing transmission efficiency and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wireless devices use higher transmit power to maintain connectivity at the edge of cells, then communication performance is improved, but RF exposure limits are exceeded and energy consumption increases

Engineering Contradiction:

Improvecommunication performanceVSAvoidRF exposure

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts transmit power based on real-time conditions including location, time, and RF exposure levels. The wireless device transitions from static power settings to adaptive power control that responds to changing environmental factors and communication needs, allowing higher power when necessary while maintaining compliance when possible.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes multiple parameters simultaneously including transmit power level, time window duration, and energy budget allocation. By adjusting these parameters dynamically based on device location, time of day, and network conditions, the system optimizes the balance between communication performance and RF exposure compliance.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If wireless devices reduce transmit power to comply with RF exposure limits, then RF exposure compliance is improved, but energy wastage increases and communication performance deteriorates

Engineering Contradiction:

ImproveRF exposure complianceVSAvoidenergy wastage

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The system performs preliminary assessments of RF exposure levels, device location, and communication requirements before determining transmit power settings. By evaluating these factors in advance and establishing an energy budget beforehand, the system avoids unnecessary power reductions and minimizes energy wastage while ensuring compliance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors RF exposure levels, transmission performance, and energy consumption, using this feedback to adjust transmit power dynamically. This closed-loop control ensures compliance is maintained only when necessary, allowing higher power usage when conditions permit, thereby reducing overall energy wastage.

Inventive Principle:

Principle #23Feedback

3Device complexity

If wireless devices use static transmit power settings, then device complexity is reduced, but adaptability to different RF exposure conditions and locations is limited

Engineering Contradiction:

Improvepower control mechanismVSAvoidRF exposure condition adaptability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The system segments the power control function into multiple independent components including location assessment module, time window determination module, energy budget calculation module, and transmit power adjustment module. This modular approach maintains manageable complexity while enabling sophisticated adaptive behavior across different RF exposure conditions.

Inventive Principle:

Principle #1Segmentation

4Adaptability or versatility

If wireless devices dynamically adjust transmit power based on location and conditions, then adaptability and energy efficiency are improved, but device complexity and computational requirements increase

Engineering Contradiction:

Improvetransmission optimizationVSAvoidpower control system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The wireless device performs self-assessment of its location relative to the base station, automatically determines appropriate time windows, calculates energy budgets, and adjusts transmit power without requiring complex external control systems. This self-service capability reduces the need for sophisticated network-side control infrastructure while maintaining high adaptability.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS20240214938A1Transmit power control with radio frequency exposure compliance

Publication Date: 2024.06.27 QUALCOMM INC

AI summary

Certain aspects of the present disclosure provide techniques and apparatus for operating a wireless device pursuant to radio frequency (RF) exposure compliance. A method that may be performed by a wireless device includes determining a transmit power associated with a transmission occasion and determining an energy usage associated with the transmission occasion based on the transmit power. The method also includes determining a total energy usage for a time window or a time interval associated with a RF exposure limit based on the energy usage associated with the transmission occasion. The method further includes transmitting a signal in the transmission occasion at the transmit power if the total energy usage satisfies an energy budget.