Uplink Power Control Lookahead for Stable Intra-Slot Transmissions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in 5G NR, changes in transmission power within a slot during uplink carrier aggregation can cause issues such as failed channel estimation and demodulation due to constellation rotation, especially for modulation schemes higher than QPSK (e.g., M-QAM), leading to inefficiencies.
Innovation Solution
The method involves calculating and adjusting transmission power allocations for overlapping uplink transmissions to eliminate power changes within a slot, using uplink power control components in user equipment and base stations to manage channel priorities and requested transmission powers, ensuring consistent power levels across multiple channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmission power is adjusted dynamically for each symbol in a slot during uplink carrier aggregation, then power allocation efficiency is improved, but transmission power stability deteriorates causing constellation rotation and demodulation failure
Solution Approach 1:
The patent applies preliminary action by performing lookahead detection of transmission power changes before they occur. The UE detects potential power changes in advance and adjusts power allocations proactively to prevent constellation rotation, rather than reacting after the damage is done. This is implemented through detecting overlapping transmissions and anticipating power adjustments that would cause instability.
Solution Approach 2:
The patent implements feedback mechanisms where the UE monitors and detects transmission power allocations across multiple uplink channels, identifies potential power changes that would cause instability, and provides feedback to adjust power allocations. This closed-loop approach ensures power stability while maintaining allocation efficiency.
2Adaptability or versatility
If transmission power changes are allowed within a slot for overlapping uplink transmissions, then power utilization flexibility is improved, but channel estimation accuracy deteriorates due to constellation rotation
Solution Approach 1:
The patent applies preliminary anti-action by detecting potential transmission power changes that would cause constellation rotation and taking preventive measures before the rotation occurs. The UE identifies overlapping transmissions and anticipates power changes, then adjusts power allocations in advance to counteract the harmful effect of constellation rotation on channel estimation.
3Productivity
If dynamic power adjustment is implemented for each uplink channel, then uplink communication efficiency is improved, but system complexity increases due to multiple channel coordination requirements
Solution Approach 1:
The patent applies merging by combining multiple uplink channel transmissions that overlap in time and would otherwise require separate power adjustments. The UE detects overlapping transmissions across multiple channels and applies unified power allocation rules, merging the coordination requirements into a single decision-making process that maintains efficiency while reducing complexity.
Data Source
AI summary
A UE may calculate an allocation of a transmission power for a first uplink transmission on a first uplink channel and at least one second uplink transmission on at least one second uplink channel, the transmission power being allocated in each symbol of a plurality of symbols in a slot. The UE may detect a transmission power change in the allocation of the transmission power in the slot for at least one of the first uplink transmission or the at least one second uplink transmission. The UE may determine whether to adjust the allocation of the transmission power for the at least one of the first uplink transmission or the at least one second uplink transmission to eliminate the transmission power change in the slot for the at least one of the first uplink transmission or the at least one second uplink transmission.