Sounding Reference Signal Power Scaling for Uplink Scheduling
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Solution Overview
Problem
In wireless communication systems, particularly in LTE-based systems with carrier aggregation, the limited maximum transmit power of user equipment poses a challenge when transmitting multiple sounding reference signals across multiple serving cells, necessitating a method to adjust the transmit power of each sounding reference signal to enable accurate uplink scheduling by the base station.
Innovation Solution
A method and apparatus for adjusting the transmit power of sounding reference signals in a wireless communication system, where the user equipment determines and adjusts the transmit power of each sounding reference signal to prevent total power exceeding the maximum allowed, ensuring accurate uplink scheduling by the base station.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sounding reference signals are transmitted in multiple serving cells, then the base station can perform more accurate uplink scheduling, but the total transmit power may exceed the user equipment's maximum allowed power
Solution Approach 1:
The patent adjusts the transmit power parameter of sounding reference signals dynamically based on the number of serving cells and power constraints. The user equipment calculates and applies power scaling factors to modify the transmit power of SRS in each serving cell, ensuring the total power remains within the maximum allowed limit while maintaining adequate signal quality for uplink scheduling
Solution Approach 2:
The patent implements dynamic power adjustment where the transmit power of sounding reference signals is not fixed but adapts based on real-time conditions including the number of active serving cells, power headroom, and scheduling requirements. This dynamic adjustment allows the system to optimize uplink scheduling accuracy while respecting power constraints
2Power
If the transmit power of each sounding reference signal is adjusted to fit within maximum power limits, then power constraints are satisfied, but the scheduling accuracy may be compromised
Solution Approach 1:
The patent applies different power adjustment strategies to different serving cells based on their individual characteristics and requirements. Instead of uniform power reduction, the system selectively adjusts power in specific cells while maintaining higher power in others, preserving local signal quality where it matters most for accurate uplink scheduling
Solution Approach 2:
The patent employs feedback mechanisms where the user equipment monitors power usage and scheduling performance, then adjusts SRS transmit power accordingly. The base station also provides feedback on scheduling accuracy, enabling iterative optimization of power levels to maintain both compliance and precision
Data Source
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AI summary
Provided are a method and apparatus for adjusting sounding reference signal transmission power. A terminal a plurality of transmit powers used for transmitting a plurality of sounding reference signals (SRSs) in a sounding reference symbol. If a total transmission power for the plurality of SRSs exceeds a maximum transmission power, the terminal scales each transmission power by the same scale factor.