Radio Station Transmit Power Control for SIR Target Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In UMTS systems, base stations face challenges in detecting changes in control signal transmit power due to rapid counteraction by closed loop power control, limiting the time available to adjust the Signal-to-Interference Ratio (SIR) target, which can lead to power step cancellation.
Innovation Solution
A modified power control algorithm in mobile stations that temporarily ignores or adjusts power control commands to create a time window for base stations to detect data signal transmission and adjust SIR targets, allowing for increased control signal power during data transmission without immediate counteraction by inner loop power control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If closed loop power control is used to adjust transmit power based on SIR feedback, then power control precision is improved, but the time available for base station to detect and adjust SIR target is reduced
Solution Approach 1:
The mobile station applies the power change before the base station can respond with power control commands. By preemptively adjusting the control signal power level at the desired time, the system creates a time window where the power change is effective before the closed loop control counteracts it.
Solution Approach 2:
The invention counteracts the harmful effect of rapid power control response by applying a preliminary power change that precedes the base station's power control commands. This preliminary action prevents the immediate counteraction that would otherwise cancel out the power adjustment.
2Reliability
If control signal transmit power is increased during data transmission, then reliable control signal reception is improved, but power consumption increases
Solution Approach 1:
The system dynamically adjusts the control signal power level based on transmission state. The power is increased when data transmission occurs and decreased when data transmission is discontinuous, allowing the system to adapt power consumption to actual operational needs while maintaining reliability during critical transmission periods.
Solution Approach 2:
The power adjustment is applied periodically according to the data transmission schedule. By synchronizing power changes with the periodic data transmission pattern, the system ensures adequate power for reliable control signal reception during active transmission while conserving power during idle periods.
3Speed
If power control commands are responded to immediately, then power control responsiveness is improved, but power step cancellation occurs
Solution Approach 1:
The mobile station applies power changes in advance before the base station's power control commands can take effect. This preliminary action creates a temporal separation that prevents the immediate counteraction and ensures power steps are stable long enough to be effective.
Solution Approach 2:
The mobile station autonomously manages the timing of its power adjustments, using its own transmission schedule to determine when to apply power changes. This self-service approach allows the mobile station to control its own power behavior and prevent cancellation by the base station's power control loop.
Data Source
Figure 1
AI summary
A radio station (100), transmits a continuous control signal and a discontinuous data signal simultaneously. It receives UP and DOWN power control commands and adjusts its transmit power by in response to the UP power control commands, increasing its transmit power by a power step, in response to the DOWN power control commands, decreasing its transmit power by a power step, in response to initiating transmission of the data signal, increasing the transmit power of the control signal, and in response to terminating transmission of the data signal, decreasing the transmit power of the control signal; In response to initiating or terminating transmission of the data signal, the radio station (100) temporarily modifies its response to the power control commands.