Uplink Power Control via Channel Quality Difference
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Solution Overview
Problem
In LTE-based small cell base stations, existing uplink power control methods fail to efficiently manage transmission power to minimize battery consumption while maintaining required channel quality, leading to potential performance degradation and increased battery drain when transmission power exceeds maximum limits.
Innovation Solution
A method and apparatus that control uplink transmission power by determining a target channel quality value based on available transmission power, using a power headroom report, and adjusting transmit power control through a difference between target and received channel quality values, with smoothing using an exponential filter, to allocate fewer resource blocks than maximum, thereby reducing battery consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transmission power is increased to maintain channel quality, then received channel quality is improved, but battery consumption increases
Solution Approach 1:
The patent implements closed-loop power control where the base station measures the actual received channel quality (SINR) and compares it with the target channel quality. Based on this feedback, the base station sends TPC commands to adjust the mobile terminal's transmission power dynamically, ensuring channel quality requirements are met while minimizing unnecessary power consumption.
Solution Approach 2:
The patent dynamically adjusts transmission power based on real-time channel conditions, mobile terminal location, and available power headroom. The system transitions from static power allocation to dynamic power control, adapting power levels to current operational needs and preventing both over-power and under-power transmission.
2Reliability
If transmission power exceeds maximum power, then channel quality may be maintained, but uplink performance degrades and battery consumption becomes severe
Solution Approach 1:
The patent performs preliminary checks before transmission by obtaining the power headroom report from the mobile terminal, which indicates the difference between maximum power and current power consumption. This preliminary information allows the base station to determine an appropriate target channel quality value that will not cause power exceeding, preventing performance degradation before it occurs.
Solution Approach 2:
The patent incorporates a cushioning mechanism by using the power headroom as a buffer indicator. The base station uses this headroom information to set target channel quality values that maintain a safety margin, preventing the transmission power from exceeding maximum limits and causing harmful effects to uplink performance.
3Reliability
If target channel quality is determined without considering available power, then channel quality requirement may be met, but transmission power may exceed maximum power
Solution Approach 1:
The patent changes the parameter used for target channel quality determination from a fixed value to a dynamic value based on power headroom. When power headroom is large, the target channel quality can be set higher; when power headroom is small, the target is adjusted downward. This parameter adaptation ensures transmission power remains within maximum limits while meeting channel quality requirements.
Data Source
AI summary
A method for controlling, by a base station, uplink transmission power of a mobile terminal. The base station receives an available transmission power amount of the mobile terminal from the mobile terminal. The base station determines a target channel quality value corresponding to a current location of the mobile terminal, on the basis of the available transmission power amount.The base station determines a received channel quality value using an uplink data channel received from the mobile terminal. Further, the base station determines a transmit power control (TPC) using a difference between the target channel quality value and the received channel quality value.