PRACH Occasion Priority Rules for Overlap-Free Random Access
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Solution Overview
Problem
In mobile communication systems, overlapping PRACH occasions configured with different repetition numbers can lead to ambiguity about which ROs are used, resulting in potential degradation of PRACH transmission and reception performance.
Innovation Solution
A method to determine invalid PRACH occasions based on overlapping configurations, using criteria such as repetition number, priority, and serving cell, to resolve ambiguity and prevent performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple PRACH occasions with different configurations are allocated to enhance coverage and support various services, then system adaptability and coverage are improved, but ambiguity arises about which ROs are used and performance degradation occurs
Solution Approach 1:
The patent applies local quality by assigning different priorities to different PRACH occasions based on their configuration characteristics (repetition number, SSB association, etc.). Each PRACH occasion is evaluated locally against the priority criterion, allowing the system to maintain multiple configurations for adaptability while locally determining which specific RO to use based on priority, thus resolving the ambiguity and performance degradation issue.
2Reliability
If PRACH occasions with different repetition numbers are configured to support varying coverage requirements, then coverage enhancement is achieved, but ambiguity about RO selection arises
Solution Approach 1:
The patent changes the parameter of priority assignment based on PRACH occasion configuration parameters such as repetition number and SSB association. By introducing priority as a derived parameter from these configuration parameters, the patent enables clear RO selection (resolving information loss) while maintaining multiple configurations for different coverage requirements.
3Adaptability or versatility
If overlapping PRACH occasions are allowed to support multiple services simultaneously, then service diversity is improved, but PRACH reception performance degrades due to overlap ambiguity
Solution Approach 1:
The patent applies local quality by evaluating each PRACH occasion individually against the priority criterion (based on repetition number, SSB association, and configuration index). This local evaluation approach allows the system to support multiple services through overlapping configurations while locally determining the single highest-priority RO to use, thereby maintaining reception accuracy despite service diversity.
Data Source
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AI summary
A method according to an embodiment of the present disclosure includes transmitting a Physical Random Access CHannel (PRACH), and receiving a Random Access Response (RAR). The PRACH is transmitted based on at least one PRACH occasion. The at least one PRACH is determined based on a plurality of PRACH occasions. The at least one PRACH is based on a valid PRACH occasion. Among the plurality of PRACH occasions, a second PRACH occasion related to a second configuration that overlaps with a first PRACH occasion related to a first configuration is determined to be invalid.