Virtual Power Headroom Reporting for Carrier Aggregation Scheduling
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Solution Overview
Problem
In LTE-Advanced carrier aggregation scenarios, existing methods fail to effectively report power headroom reports (PHRs) in various transmission scenarios, leading to inadequate uplink scheduling by the eNB.
Innovation Solution
A method and apparatus for reporting PHRs that involve calculating and reporting virtual type1 and type2 PHRs, even when no PUSCH or PUCCH is transmitted, and encapsulating PHRs with mode indicating information to cover all UL CCs, allowing for flexible reporting based on transmission scenarios and power backoff conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PHR reporting is performed only when PUSCH is actually transmitted, then the reporting procedure is simple, but the eNB cannot obtain accurate power headroom information when PUSCH transmission is suspended
Solution Approach 1:
The patent introduces virtual PHR reporting that calculates and reports power headroom information in advance based on reference formats, even when PUSCH transmission is not actually occurring. This preliminary action ensures the eNB has current power headroom information for scheduling decisions without waiting for actual PUSCH transmission events.
Solution Approach 2:
The patent creates virtual copies of PHR information by calculating power headroom based on reference transmission formats. These virtual PHR values are generated as copies of what the PHR would be under reference conditions, allowing the eNB to make scheduling decisions based on representative power headroom data even when actual transmission conditions differ.
2Loss of information
If separate PHR reporting is performed for each component carrier, then the eNB obtains detailed power information per carrier, but the signaling overhead and reporting complexity increase
Solution Approach 1:
The patent merges PHR reporting for multiple component carriers into a single unified reporting mechanism. By combining the power headroom information from multiple carriers into one report, the system reduces signaling overhead and reporting complexity while maintaining complete power information for all carriers through the unified structure.
3Measurement precision
If PHR is reported frequently to ensure accurate scheduling, then the scheduling accuracy improves, but the uplink control channel resources are consumed
Solution Approach 1:
The patent implements periodic PHR reporting based on configured periods and triggers. Instead of continuous reporting, the system uses periodic action where PHR is reported at scheduled intervals or when specific trigger conditions are met, balancing scheduling accuracy with resource conservation by avoiding unnecessary frequent reports.
Data Source
AI summary
A method and apparatus are disclosed for reporting a power headroom report (PHR) in a carrier aggregation scenario. The method includes the following steps: when a user equipment (UE) reports the PHR in a scenario where a physical uplink control channel (PUCCH) and a physical uplink shared channel (PUSCH) can be transmitted concurrently, if no PUSCH is transmitted over the Uplink Primary Component Carrier (UL PCC) configured by an eNB for the UE, then a virtual type1 PH and/or a virtual type2 PH corresponding to the UL PCC are reported; if a PUSCH rather than a PUCCH is transmitted over the UL PCC configured by the eNB for the UE, then the type1 PH corresponding to the UL PCC is reported or the virtual type2 PH and the type1 PH corresponding to the UL PCC are reported. User equipment is also disclosed.