Power Headroom Management in Wireless Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face challenges in managing power headroom to minimize spurious emissions and comply with spectral mask requirements, particularly in efficiently allocating bandwidth and adjusting power levels across different frequency subcarriers.
Innovation Solution
The method involves identifying bandwidth allocations, determining their locations within the frequency band, and selecting power backoff parameters using predefined mappings to reduce transmit power while ensuring compliance with spectral masks, employing pre-configured lookup tables to associate spectral assignments with corresponding power reductions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the terminal operates at maximum power amplifier output power, then the data rate and transmission capacity are maximized, but spurious emissions increase and spectral mask requirements are violated
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the power amplifier output power based on the bandwidth allocation size. Different power backoff values are applied depending on whether the allocation is small, medium, or large, thereby optimizing the balance between data rate and spurious emissions for each allocation scenario
Solution Approach 2:
The system implements dynamic power management where the power backoff is not fixed but adapts based on real-time bandwidth allocation decisions. The terminal autonomously determines the appropriate power level based on the allocated bandwidth, making the power setting dynamic rather than static
2Object-generated harmful factors
If power backoff is applied to minimize spurious emissions, then spectral mask requirements are met, but the available power headroom is reduced
Solution Approach 1:
The patent implements parameter changes by selecting different power backoff values based on the bandwidth allocation size. Small allocations receive larger backoff values to minimize spurious emissions, while large allocations receive smaller backoff values to preserve power headroom, optimizing the trade-off for each scenario
Solution Approach 2:
The power backoff is made dynamic and adaptive rather than fixed. The terminal autonomously determines the appropriate backoff level based on the actual bandwidth allocation received from the eNodeB, allowing the system to optimize power usage in real-time based on actual transmission needs
3Device complexity
If fixed power backoff values are used for all bandwidth allocations, then the system is simple to implement, but power management efficiency is reduced
Solution Approach 1:
The patent transforms fixed power backoff into dynamic power backoff that adapts to different bandwidth allocation scenarios. The terminal autonomously determines the appropriate backoff value based on the allocation size, significantly improving power management efficiency while maintaining relatively simple implementation through predefined thresholds
Solution Approach 2:
The system implements parameter changes by establishing different power backoff values corresponding to different bandwidth allocation sizes (small, medium, large). This segmented approach to power management improves efficiency by optimizing power usage for each allocation scenario while keeping the implementation simple through clear categorization
Data Source
AI summary
Systems and methodologies are described that facilitate power headroom management in a wireless communication system. As described herein, a predefined relationship between locations along a system frequency band and corresponding power backoff parameters is utilized to minimize spurious emissions outside the system frequency band and/or excessive interference by, for example, associating locations near one or more edges of the permitted frequency band with substantially high power backoff parameters. As further described herein, the predefined relationship can be known a priori to the base station and the mobile terminal.