Uplink Power Control for Partially Overlapped Subframes
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Solution Overview
Problem
In LTE-A R11, user equipment (UE) experiences power limitations or interference when transmitting uplink channels on carriers with different timing advance values, leading to partial subframe overlap and exceeding maximum transmission power or interference levels.
Innovation Solution
The UE processes uplink channels by adjusting transmission power on the last symbol of partially overlapped subframes, specifically by subtracting or reallocating power from the carrier with the greatest timing advance value, to maintain total transmission power below the maximum or interference level, thereby preventing power or interference issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE transmits uplink channels on carriers with different timing advance values, then uplink transmission synchronization is achieved, but total transmission power exceeds maximum power or interference level
Solution Approach 1:
The patent applies partial action by processing only the last symbol of the partially overlapped subframe on the carrier with the greatest TA value. Instead of reducing power across all symbols or all carriers, the solution selectively handles only the specific symbol and carrier combination that causes the power excess, thereby achieving power control with minimal impact on overall transmission performance
Solution Approach 2:
The patent applies local quality by making different parts of the transmission have different properties. Specifically, the last symbol on the carrier with greatest TA value is treated differently (processed to reduce power) compared to other symbols and carriers. This localized processing ensures that power control is applied precisely where needed without affecting the quality of other transmission portions
2Power
If the UE processes uplink channels by adjusting transmission power on the last symbol of partially overlapped subframes, then total transmission power is maintained below maximum level, but transmission efficiency is reduced
Solution Approach 1:
The patent minimizes the impact on transmission efficiency by applying power adjustment to only the last symbol of the partially overlapped subframe on the carrier with the greatest TA value. This partial action approach ensures that power control is achieved with the smallest possible reduction in overall transmission efficiency, as most other symbols and carriers continue to transmit at optimal power levels
Data Source
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AI summary
An uplink transmission power control method and a user equipment are provided, where the method includes: determining, by a UE, whether uplink channels are simultaneously transmitted over adjacent sub frames between multiple carriers; where the adjacent subframes between the multiple carriers are partially overlapped; and timing advance values of the multiple carriers are different; and if uplink channels are simultaneously transmitted over adjacent sub frames between multiple carriers, processing, by the user equipment, an uplink channel transmitted over the last symbol on a partially overlapped subframe of another carrier except a carrier having the greatest timing advance value, so that total transmission power of the uplink channels is lower than the maximum transmission power or an interference level of the user equipment. In the embodiments of the present invention, when the UE sends the uplink channels through carriers of different TAGs and adjacent subframes between the carriers of different TAGs are partially overlapped, uplink transmission power of the UE may be prevented from exceeding the maximum transmission power of the UE, or uplink transmission power of the UE may be prevented from reaching an interference level so as to result in an interference limitation.