Uplink Transmit Power Backoff for Thermal Overheating

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Solution Overview

Problem

Wireless communication devices supporting high data rates, such as those using advanced radio access technologies like LTE, face overheating issues due to high power consumption and thermal management challenges, particularly with power amplifiers operating at full power, which existing uplink flow control methods like reducing Medium Access Control (MAC) layer data rates or buffer status reports do not effectively address.

Innovation Solution

Implementing methods and apparatus for uplink flow control that include determining if an overload metric has exceeded a threshold, and modifying the transmit power of uplink control channels by selectively not transmitting during off-cycle periods or applying a power back-off to reduce thermal issues, specifically by duty cycling the uplink control channel or reducing the maximum transmit power limit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high data rates are supported using advanced radio access technologies, then communication throughput is improved, but thermal overheating and power consumption increase

Engineering Contradiction:
Improvedata rateVSAvoidthermal overheating
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent implements periodic action by introducing discontinuous transmission cycles for uplink control channels, where transmissions are periodically enabled or disabled based on thermal conditions. The system monitors temperature and dynamically adjusts the transmission cycle, enabling periodic uplink control channel transmissions only when thermal thresholds are met, thereby reducing average power consumption and thermal overheating while maintaining high data rate capability when needed.

Inventive Principle:
Principle #19Periodic action

2Temperature

If transmit power is reduced to mitigate thermal issues, then temperature is improved, but communication reliability deteriorates

Engineering Contradiction:
Improvethermal overheatingVSAvoidcommunication reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies dynamics by implementing dynamic transmit power adjustment and discontinuous transmission cycling for uplink control channels. The system continuously monitors thermal conditions and dynamically adapts the transmission strategy - enabling full power transmission when cool and reducing to periodic or disabled transmission when thermal thresholds are exceeded. This dynamic adaptation maintains communication reliability by ensuring sufficient transmission power is available when thermal conditions permit, while preventing overheating when they do not.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback mechanisms by continuously monitoring thermal conditions and using this information to adjust uplink control channel transmission behavior. The system measures temperature, compares it against thresholds, and feeds this information back to control the transmission cycling and power level. This closed-loop feedback ensures that transmit power is reduced only when necessary to prevent overheating, thereby maintaining communication reliability while managing thermal issues.

Inventive Principle:
Principle #23Feedback

3Device complexity

If existing uplink flow control methods are used to manage power, then device complexity is reduced, but thermal mitigation effectiveness is insufficient

Engineering Contradiction:
Improvecontrol mechanism simplicityVSAvoidthermal overheating
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent applies segmentation by dividing the uplink control channel transmission into discrete, controllable segments or cycles. Instead of treating uplink control channel transmission as a continuous process, the system segments it into individual transmission opportunities that can be independently enabled or disabled based on thermal conditions. This segmentation allows for granular control over power consumption while maintaining relatively simple implementation through basic transmission cycling logic.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2742745B1Methods and apparatus for overload mitigation using uplink transmit power backoff
Publication Date: 2018.01.03 QUALCOMM INC
  • EP2742745B1 patent drawingFigure 1~2
  • EP2742745B1 patent drawingFigure 3
  • EP2742745B1 patent drawingFigure 4~5

AI summary

Certain aspects of the disclosure relate generally to uplink flow control of wireless devices for mitigation of overload issues. A user equipment (UE) may reduce an average transmit power for the uplink channel based on whether an overload metric (e.g., temperature metric) exceeds a threshold value. The UE may perform duty cycling for an uplink control channel when an overactive uplink control channel is a dominating factor in a thermal issue. The UE may further reduce a maximum power transmit limit (MTPL) for one or more uplink channels, such as physical uplink control channel (PUCCH) and physical uplink shared channel (PUSCH).