Random Access Procedure in Unlicensed Band Wireless Systems
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Solution Overview
Problem
In wireless communication systems, performing a random access procedure in an unlicensed band is challenging due to the need for efficient channel access and collision avoidance with other devices, especially when multiple beam resources are involved.
Innovation Solution
A method for a user equipment (UE) to perform a random access procedure in a wireless communication system supporting an unlicensed band, involving multiple channel access procedures with different configurations, including varying transmission power, beam configurations, and energy detection thresholds, to successfully transmit a random access channel preamble, ensuring successful channel access and minimizing collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single channel access procedure is used for random access in unlicensed band, then the procedure is simple, but collision avoidance and access reliability are insufficient
Solution Approach 1:
The patent divides the channel access procedure into multiple distinct procedures (first channel access procedure and second channel access procedure) with different configurations. The first procedure uses initial parameters while the second procedure uses modified parameters including adjusted transmission power and energy detection thresholds. This segmentation allows the system to try different access strategies to improve reliability without requiring a completely complex unified procedure.
Solution Approach 2:
The patent modifies key parameters between the first and second channel access procedures, including transmission power levels, energy detection thresholds, and beam configurations. When the first procedure fails, the system transitions to the second procedure with adjusted parameters, allowing adaptation to changing channel conditions and improving overall access reliability while maintaining manageable complexity through structured parameter management.
2Adaptability or versatility
If multiple beam resources are used for random access, then coverage and access opportunities increase, but collision probability and procedure complexity increase
Solution Approach 1:
The patent associates different beam configurations with different channel access procedures. The first channel access procedure uses an initial beam configuration while the second procedure uses a modified beam configuration. This segmentation of beam resources across different procedures helps manage complexity by organizing beam management within structured procedure frameworks rather than requiring simultaneous management of all beams.
Solution Approach 2:
The patent enables dynamic switching between different beam configurations based on the success or failure of channel access procedures. When the first procedure fails, the system dynamically transitions to the second procedure with different beam settings, allowing adaptation to channel conditions and improving access success probability while maintaining manageable complexity through conditional transitions.
3Reliability
If transmission power is increased for random access preamble, then access success probability improves, but energy consumption and interference increase
Solution Approach 1:
The patent implements dynamic transmission power adjustment across different channel access procedures. The first procedure uses an initial transmission power level, and the second procedure uses a modified power level based on the outcome of the first procedure. This dynamic approach allows the system to increase power only when necessary (when the first procedure fails), improving access success probability while minimizing unnecessary energy consumption and interference.
Solution Approach 2:
The patent modifies transmission power as a key parameter when transitioning from the first to the second channel access procedure. By adjusting the power level based on procedure outcome and channel conditions, the system optimizes the trade-off between access success probability and energy consumption, avoiding sustained high-power transmission while maintaining reliability through conditional power increases.
Data Source
AI summary
The present invention provides a method for performing a random access procedure by a terminal in a wireless communication system supporting an unlicensed band and a terminal for performing the same. Particularly, the present invention provides a method for, when a terminal and a base station can transmit or receive a signal using various beam resources, performing a random access procedure for the base station by the terminal via an unlicensed band, and the terminal for performing the same.