Power Headroom Reporting in Multi-Carrier LTE Systems
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Solution Overview
Problem
The existing Power Headroom Reporting (PHR) mechanism in LTE systems is limited to single-carrier systems and cannot be applied to multi-carrier systems, preventing user equipment in LTE-Advanced systems from reporting power headroom, which hinders base station uplink scheduling.
Innovation Solution
The solution enables power headroom reporting in multi-carrier systems by allowing user equipment to trigger and report power headroom independently or associatively based on Component Carriers (CC) or Power Amplifiers (PA), using configured PHR-related parameters to facilitate better uplink scheduling by base stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing PHR mechanism is applied to multi-carrier systems, then the system can report power headroom for multiple carriers, but the complexity of the reporting mechanism increases significantly
Solution Approach 1:
The patent segments the power headroom reporting by introducing separate reporting mechanisms for different component carriers. Each carrier can be independently configured with its own PHR parameters (periodicPHR-Timer, prohibitPHR-Timer, dl-PathlossChange), allowing the system to handle multi-carrier scenarios through modular, independent reporting units rather than a monolithic complex mechanism
Solution Approach 2:
The patent introduces dynamic triggering conditions for PHR based on pathloss changes specific to each carrier. The trigger conditions (pathloss change exceeding dl-PathlossChange threshold, timer expirations) allow the system to adaptively activate reporting only when necessary for each carrier, reducing unnecessary reporting overhead while maintaining accuracy across multiple carriers
2Measurement precision
If power headroom reporting is enabled for each component carrier independently, then the scheduling accuracy improves, but the signaling overhead increases
Solution Approach 1:
The patent applies local quality by configuring PHR parameters independently for each component carrier based on its specific characteristics. Each carrier can have customized periodicPHR-Timer, prohibitPHR-Timer, and dl-PathlossChange values tailored to its channel conditions and traffic requirements, optimizing reporting precision locally without uniformly increasing overhead across all carriers
Solution Approach 2:
The patent utilizes parameter changes by allowing the network to dynamically adjust PHR-related parameters (periodicPHR-Timer periods, prohibitPHR-Timer values, dl-PathlossChange thresholds) for each carrier via RRC configuration. This enables the system to optimize the balance between scheduling accuracy and signaling overhead by adjusting parameter values based on actual network conditions and carrier importance
Data Source
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AI summary
A method, device and system for reporting power headroom are provided, and the method includes the following steps: a user equipment determines whether it triggers power headroom reporting (PHR) (101); if triggering PHR, the user equipment reports power headroom independently or associatively basing on a component carrier (CC) or a power amplifier (PA) (102). The technical solution realizes power headroom reporting in a multi-carrier system by reporting power headroom independently or associatively basing on the CC or the PA, and can make a base station equipment process uplink scheduling better according to the power headroom coming from the user equipment.