Transmit Power Control for SAR-Limited Uplink Signal Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic devices face challenges in managing transmit power to comply with specific absorption rate (SAR) regulations, leading to issues such as uplink signal deterioration and dropped calls during real-time services.
Innovation Solution
The method involves determining upper and lower limit values of transmit power based on service scenarios, adjusting power levels dynamically to maintain average power compliance with SAR requirements, thereby reducing the duration of lower power transmission and improving signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electronic device transmits with full power Pmax in a certain duration to improve signal quality, then the signal quality is improved, but the average power exceeds the SAR limit Plimit causing health concerns and regulatory non-compliance
Solution Approach 1:
The patent applies periodic action by dividing the time window into multiple transmission opportunities with different power levels. The device transmits at full power Pmax during certain durations and at reduced power (Plimit-margin) during other durations within the same time window, creating a periodic transmission pattern that achieves both high signal quality during full-power transmission and SAR compliance through averaged power control.
Solution Approach 2:
The patent implements dynamics by dynamically adjusting the transmit power level based on the elapsed time within the time window. The power control mechanism transitions between different power states (Pmax and Plimit-margin) depending on the current time position, allowing the system to adaptively optimize signal quality while maintaining SAR compliance throughout the transmission process.
2Object-affected harmful factors
If the electronic device transmits with reduced power (Plimit-margin) to comply with SAR regulations, then the SAR requirement is satisfied, but the uplink signal deteriorates and causes dropped calls or silence
Solution Approach 1:
The patent uses periodic action to alternate between full-power transmission (Pmax) and reduced-power transmission (Plimit-margin) within the time window. This periodic pattern ensures that SAR compliance is maintained through averaged power control while signal quality is preserved during full-power transmission intervals, preventing dropped calls and silence issues that would result from continuous reduced-power transmission.
Solution Approach 2:
The patent applies preliminary action by calculating and determining the optimal power levels and transmission durations in advance based on the time window parameters and SAR limits. This preliminary power configuration ensures that the device can immediately execute the power control strategy without delay, maintaining both SAR compliance and signal quality from the start of transmission.
3Object-affected harmful factors
If the electronic device uses a fixed time window (e.g., 360s for ICNIRP or 100s for FCC) to control average power, then the SAR regulation is complied with, but the transmission efficiency is reduced due to prolonged lower power transmission
Solution Approach 1:
The patent implements periodic action by structuring the time window into repeated cycles of full-power and reduced-power transmission. This periodic pattern allows the device to maximize the utilization of full-power transmission intervals while ensuring that the averaged power over the complete time window remains within SAR limits, thereby optimizing transmission efficiency without compromising regulatory compliance.
Solution Approach 2:
The patent applies parameter changes by dynamically modifying the transmit power parameter between two discrete levels (Pmax and Plimit-margin) based on the position within the time window. This parameter switching strategy enables the system to achieve the maximum possible transmission efficiency by spending as much time as possible at full power while still satisfying the averaged power constraint imposed by SAR regulations.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A method for controlling an electronic device, includes: obtaining a service scenario of the electronic device; determining an upper limit value and/or a lower limit value of a transmit power based on the service scenario; controlling the electronic device to transmit and receive signals by using the transmit power, and making an average value of the transmit power satisfy an SAR requirement.