Radio Terminal Power Control via Uplink Reflection Detection
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Solution Overview
Problem
Handheld devices operating at higher frequencies face challenges in detecting human tissue proximity to prevent excessive power density exposure, which is regulated by safety thresholds, and existing antenna arrays suffer from phase variation and limited detection distance.
Innovation Solution
The apparatus uses a scheduled uplink transmission as a proximity detection reference signal, integrating safety control with the transmission source, and employs multiple antennas to differentiate between reflection and direct radio path coupling, enabling accurate detection of proximal objects through power headroom reports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing antenna arrays are used for proximity detection, then detection capability is provided, but phase variation and limited detection distance occur
Solution Approach 1:
The antenna array is segmented into dedicated transmit antennas and receive antennas, allowing separate optimization of transmission and detection functions. This segmentation enables the system to detect reflections with improved accuracy while maintaining stable operation by isolating the detection path from transmission phase variations.
Solution Approach 2:
The patent introduces an intermediary detection mechanism using scheduled uplink transmissions as reference signals. By using these transmissions as intermediaries to probe the environment and detect reflections, the system achieves accurate proximity detection without directly using the main communication signals, thereby avoiding phase variation issues.
2Productivity
If transmission power is increased to improve communication performance, then data rate is improved, but power density exposure to human tissue increases
Solution Approach 1:
The system implements feedback through power headroom reports that include MPE event indicators. When proximity detection identifies potential human tissue exposure, the system feeds back power reduction commands to the transmit antennas, dynamically adjusting transmission power to maintain both communication performance and safety compliance.
Solution Approach 2:
The transmission power is made dynamic rather than static. The system continuously monitors proximity conditions and adjusts transmit power in real-time based on detected reflections and MPE event indicators, allowing maximum power when safe and reduced power when human tissue is detected.
3Measurement precision
If dedicated detection antennas are added to improve detection accuracy, then detection precision is improved, but device complexity increases
Solution Approach 1:
The antenna array serves multiple functions: dedicated transmit antennas for communication and dedicated receive antennas for proximity detection. This multi-functionality allows the system to achieve accurate detection without requiring separate detection hardware, as the receive antennas are part of the existing antenna array structure.
Solution Approach 2:
The detection function is merged with the existing communication infrastructure by using scheduled uplink transmissions as reference signals for proximity detection. This combining approach allows the system to achieve accurate detection without adding completely separate detection hardware, thereby limiting the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for effective reduction of transmitted power when human tissue is detected, ensuring compliance with safety thresholds and improving the accuracy of proximity detection, thereby enhancing safety and operational efficiency.
Implementation Method 1
detect at the second antenna reflection of the uplink transmission
Data Source
AI summary
An apparatus including at least one processor; and at least one memory including computer program code with the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to control: receiving scheduling information for uplink transmission; performing at least one scheduled uplink transmission according to the scheduling information; controlling content of a power headroom report in dependence upon detection of a reflection of the scheduled uplink transmission; and transmitting the power headroom report having content controlled in dependence upon detection of the reflection of the scheduled uplink transmission.