Power Headroom Reporting Across Multiple TCI States
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing power headroom reporting, particularly in scenarios involving multiple transmission configuration indicator states, leading to suboptimal power control and resource utilization.
Innovation Solution
A method for a wireless device to receive configuration parameters and TCI states, and transmit a power headroom medium-access control element based on first power control parameters and pathloss reference signals, enabling accurate reporting of Type 1 power headroom values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple TCI states are configured for a cell, then the system supports diverse transmission configurations and beam directions, but the power headroom reporting complexity increases and power control accuracy deteriorates
Solution Approach 1:
The patent segments the power headroom reporting by associating different TCI states with different uplink power control sets. Each TCI state has a corresponding power control set containing specific parameters (P0, alpha, pathloss reference signals), allowing the system to calculate and report power headroom values separately for each TCI state rather than using a single aggregated value. This segmentation resolves the contradiction by maintaining reporting accuracy through individualized power control parameters while supporting multiple TCI states.
Solution Approach 2:
The patent applies local quality by configuring cell-specific power control parameters that are locally optimized for each TCI state. Different SRS resource sets are associated with different TCI states, and each has its own power control parameters tailored to the specific beam characteristics and pathloss conditions of that TCI state. This localized parameter configuration ensures accurate power headroom reporting for each transmission configuration while maintaining overall system versatility.
2Measurement precision
If separate power control parameters are configured for each TCI state, then power headroom reporting accuracy improves, but the configuration complexity and device overhead increase
Solution Approach 1:
The patent implements universality by creating a unified power control framework where uplink power control sets are universally applicable across multiple TCI states through systematic associations. The base station configures power control parameters in a standardized manner that can be reused across different TCI states and SRS resource sets, reducing the need for entirely separate configurations for each TCI state. This universal framework maintains reporting accuracy while minimizing configuration complexity through pattern-based parameter allocation.
Solution Approach 2:
The patent applies preliminary action by pre-configuring uplink power control sets and associating them with TCI states before actual power headroom reporting occurs. The base station establishes the mapping between TCI states, SRS resource sets, and power control parameters in advance through RRC configuration, so that when power headroom reporting is triggered, the wireless device can directly use the pre-established associations without complex real-time calculations. This preliminary configuration reduces device complexity during operation while maintaining accurate reporting.
3Reliability
If comprehensive power control parameters are maintained for all TCI states, then power control accuracy is preserved, but the signaling overhead and processing requirements increase
Solution Approach 1:
The patent extracts and reports only the essential power headroom information needed for each TCI state rather than transmitting complete power control parameter sets. The wireless device calculates power headroom values based on the pre-configured power control parameters and reports only the resulting PHR values along with indicators identifying which TCI state each value corresponds to. This extraction approach preserves power control accuracy by maintaining complete parameter configurations at the base station while reducing signaling overhead by transmitting only the critical derived information.
Solution Approach 2:
The patent uses copying by having the wireless device compute power headroom values that replicate the base station's expected calculations using the same pre-configured parameters. Instead of transmitting the actual power control parameter sets, the device generates copied results (power headroom values) that reflect the accuracy of parameter maintenance without requiring the parameters themselves to be re-transmitted. This copying mechanism preserves power control reliability while minimizing signaling overhead.
Data Source
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Figure 3
AI summary
A wireless device may receive one or more configuration parameters indicating a plurality of transmission configuration indicator (TCI) states for a cell. In response to the one or more configuration parameters not comprising a two-powerheadroom-report-mode (twoPHRMode) parameter, the wireless device may transmit a power headroom report indicating a power headroom value calculated using power control parameters associated with a TCI state among at least two active TCI states of the plurality of TCI states.