Multi-TRP Power Headroom Reporting for Low-Latency Uplink Scheduling
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Solution Overview
Problem
The challenge in wireless communication systems is the efficient utilization of limited radio resources by base stations to manage uplink and downlink data and control information, particularly in scenarios with multiple TRPs, where latency and delay are critical, and existing methods for transmitting Power Headroom Reports (PHRs) are inadequate.
Innovation Solution
A method and apparatus for transmitting PHRs by user equipment (UE) that enhance PHR reporting by calculating and reporting multiple power headroom values for serving cells, including both single and multi-TRP configurations, optimizing resource allocation and reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the UE transmits PHR for multiple TRPs in twoPHRMode through a cell group configured with twoPHRMode, then the network can obtain detailed power headroom information for each TRP, but the device complexity and processing overhead increase significantly
Solution Approach 1:
The patent segments the PHR information by creating separate fields for different TRPs (e.g., phr-TRP0, phr-TRP1) within the twoPHRMode report structure. This segmentation allows the network to receive detailed power headroom information for each TRP independently while maintaining a structured and organized report format that reduces processing complexity compared to unstructured multi-TRP reporting.
Solution Approach 2:
The patent introduces an intermediary mechanism by using a unified PHR reporting structure that can accommodate both single-TRP and multi-TRP scenarios. The twoPHRMode configuration acts as an intermediary layer that translates multiple TRP power headroom values into a standardized format, enabling backward compatibility while providing enhanced information when needed.
2Reliability
If the network configures twoPHRMode on all cell groups, then PHR interpretation is consistent across all cell groups, but the adaptability to different network configurations is reduced
Solution Approach 1:
The patent implements dynamic configuration by allowing each cell group to be independently configured with or without twoPHRMode. The UE adapts its PHR transmission behavior based on the configuration status of each cell group, transmitting detailed multi-TRP information only to cell groups that are configured to receive it, while maintaining compatibility with cell groups that use traditional single-TRP reporting.
Solution Approach 2:
The patent creates a universal PHR reporting mechanism that can function in multiple modes. The same PHR structure and transmission procedure can be used whether the cell group is configured with twoPHRMode or not, providing backward compatibility and flexible adaptability to different network deployment scenarios without requiring separate reporting mechanisms.
3Loss of information
If the UE includes all power headroom values for multiple TRPs in the PHR, then the network has complete information for scheduling decisions, but the message size and transmission overhead increase
Solution Approach 1:
The patent extracts only the necessary power headroom information for each TRP into dedicated fields within the PHR structure. By selectively including only the relevant phr-TRP0, phr-TRP1, and other TRP-specific fields that are actually needed for scheduling decisions, the patent reduces message overhead compared to including all possible measurement data, while still providing complete information for multi-TRP scheduling.
4Adaptability or versatility
If the UE prioritizes transmitting PHR through cell groups not configured with twoPHRMode, then compatibility is maintained with legacy networks, but the efficiency of delivering accurate power headroom information decreases
Solution Approach 1:
The patent uses a copying approach by maintaining the same basic PHR message structure and transmission procedures for both twoPHRMode-configured and non-configured cell groups. The UE copies the standard PHR formatting and includes appropriate fields based on configuration, ensuring that legacy networks can interpret the reports correctly while networks with twoPHRMode configuration can extract the enhanced multi-TRP information efficiently.
Data Source
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AI summary
A method for transmitting a power headroom report (PHR) by a user equipment (UE) in a wireless communication system is disclosed. The method comprises steps of selecting a first power headroom value among power headroom values for two or more Transmission and Reception Points (TRPs) of a serving cell belonging to a first cell group configured with two PHR mode; generating the PHR including the first power headroom value; transmitting the PHR to a network through a second cell group not configured with the two PHR mode, wherein the first power headroom value is related to a TRP on which a real transmission occurs among the two or more TRPs.