Power Headroom Reporting with Negative Values
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power headroom reporting in LTE systems only provides positive values, failing to indicate when the required transmit power exceeds the nominal maximum, leading to inefficient resource allocation and potential waste of air interface resources due to lack of knowledge about 'missing' power at User Equipment (UE).
Innovation Solution
Extending power headroom reporting to include negative values, allowing User Equipment (UE) to inform the eNodeB about the amount of missing power in dB, enabling the eNodeB scheduler to adjust resource allocation, modulation, and power control, thereby optimizing bandwidth and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If power headroom reporting only provides positive values, then the reporting mechanism is simple, but the eNodeB cannot determine when required transmit power exceeds nominal maximum, leading to inefficient resource allocation
Solution Approach 1:
The patent extends the power headroom reporting parameter from only positive values to include negative values. When the required transmit power exceeds the nominal maximum, the UE reports a negative power headroom value, enabling the eNodeB to detect power deficiency conditions and adjust resource allocation accordingly, thus resolving the contradiction between simplicity and efficiency
2Measurement precision
If power headroom reporting includes negative values, then the eNodeB can accurately determine missing power and optimize resource allocation, but the reporting mechanism becomes more complex
Solution Approach 1:
The patent modifies the power headroom parameter to accommodate negative values while maintaining the existing reporting framework. The UE calculates power headroom as the difference between nominal maximum power and required transmit power, and reports this value (positive or negative) using the existing 5-bit field, thus achieving enhanced measurement precision without significant increase in system complexity
3Loss of energy
If the eNodeB scheduler adjusts resource allocation based on negative power headroom values, then bandwidth waste is reduced, but the processing complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the UE reports negative power headroom values to the eNodeB, which then adjusts resource allocation in subsequent scheduling decisions. This closed-loop feedback enables the system to reduce bandwidth waste by allocating fewer resource blocks when power is deficient, while the processing complexity remains manageable as it involves standard scheduling adjustments
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method can include determinin g a power headroom report, and transmitting the headroom report. The power headroom repor t can provide both positive and negative values of power headroom accordin g to the determination, in which negative values indicate the missing power in dB to fulfill requirements, such as those given by current resource allo cation and modulation an d coding scheme. This method can be implemented by enco ding instructions for performing this method on a computer-readable medium, su ch that the instructions when execute cause the computer to execut e the method as a computer process. The method can further include receiving a power headroom report. The method can additionally include allocating radio network resources based on the power headroom report.