PRACH Power Allocation in Dual Connectivity User Terminals
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Solution Overview
Problem
In dual connectivity scenarios of next-generation mobile communication systems, there is no established rule for allocating power to the Physical Random Access Channel (PRACH), which can lead to unpredictable power scaling and dropping, affecting the quality and throughput of uplink communication.
Innovation Solution
The introduction of guaranteed transmission power per cell group for PRACH, allowing user terminals to allocate power based on guaranteed and maximum transmission powers, ensuring adequate power allocation and preventing power-limited states that could disrupt communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If power scaling is applied to PRACH transmissions in dual connectivity, then power allocation becomes flexible across multiple cell groups, but communication reliability deteriorates due to unpredictable power dropping
Solution Approach 1:
The patent applies local quality by differentiating power allocation rules between different cell groups. The master cell group (MCG) is assigned guaranteed transmission power to ensure reliable PRACH access, while the secondary cell group (SCG) uses power scaling for flexibility. This localized differentiation resolves the contradiction by ensuring reliability where needed (MCG) while maintaining adaptability where possible (SCG).
Solution Approach 2:
The patent implements preliminary action by establishing guaranteed transmission power for the MCG before PRACH transmission occurs. This pre-allocation ensures that critical random access procedures have sufficient power reserved, preventing power dropping and ensuring communication reliability before the actual transmission takes place.
2Reliability
If guaranteed transmission power is allocated per cell group, then PRACH access reliability is improved, but device complexity increases due to additional power management mechanisms
Solution Approach 1:
The patent segments the dual connectivity system into two distinct cell groups with different power management approaches: MCG with guaranteed power and SCG with scalable power. This segmentation simplifies the overall power management complexity by creating clear, separate rules for each cell group rather than attempting a unified complex allocation scheme, while still improving PRACH reliability through the guaranteed MCG power allocation.
3Use of energy by moving object
If power scaling is used for uplink transmissions, then power utilization efficiency is improved, but uplink throughput deteriorates due to power dropping
Solution Approach 1:
The patent applies local quality by restricting power scaling to non-critical uplink transmissions (PUSCH, PUCCH, SRS) while guaranteeing power for critical PRACH access. This localized application maintains power utilization efficiency for data transmissions while protecting uplink throughput by ensuring reliable random access and control channel operations are not affected by power dropping.
Data Source
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AI summary
The present invention is designed to adequately allocate power to the PRACH in dual connectivity. A user terminal communicates with a plurality of cell groups, each cell group being comprised of one or more cells that use different frequencies, and this user terminal has a transmission section that transmits a physical random access channel (PRACH) in a random access procedure, and a power control section that executes power control for transmitting the PRACH, and when the transmission power required for the PRACH to transmit to a master base station exceeds a threshold, the power control section executes control to stop uplink transmission to a secondary base station.