Adaptive Random Access Preamble Repetition for TDD Alignment
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Solution Overview
Problem
In wireless communication systems, determining the optimal number of times to repeat a random access preamble for uplink synchronization is challenging, particularly in configurations where the number of uplink slots does not align with integer multiples of 3, 5, or 7, leading to potential mismatches with TDD configurations.
Innovation Solution
A communication method and apparatus that determine the number of times to repeat a random access preamble based on received signal power and sets including integer multiples of 3, 5, or 7, ensuring alignment with TDD configurations, and adjust frequency and time domain positions of random access occasions to avoid overlap and improve synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal repeatedly sends the random access preamble multiple times to increase received power, then the uplink synchronization reliability is improved, but the random access duration becomes excessively long
Solution Approach 1:
The patent implements dynamic adjustment of the random access preamble repetition quantity based on received signal power measurements. The terminal adapts the repetition count to match TDD configuration patterns (integer multiples of 3, 5, or 7), allowing the system to optimize between reliability and duration in real-time rather than using fixed repetition values
Solution Approach 2:
The patent changes the parameter of repetition quantity from static to dynamic by introducing adaptive selection based on received power and TDD configuration matching. This allows the system to select optimal repetition counts that satisfy both reliability requirements and duration constraints through parameter optimization
2Adaptability or versatility
If the set of repetition quantities does not include integer multiples of 3, 5, or 7, then the flexibility in selecting repetition counts is improved, but the alignment with TDD configuration is worsened
Solution Approach 1:
The patent applies local quality by creating specialized subsets of repetition quantities tailored to specific TDD configurations. Different TDD patterns (with 3, 5, or 7 uplink slots) have corresponding customized repetition sets, allowing optimal local matching between repetition patterns and TDD structures while maintaining overall system flexibility
Solution Approach 2:
The system dynamically selects appropriate repetition quantity sets based on the detected TDD configuration type. This dynamic adaptation ensures that the repetition pattern always aligns with the active TDD structure, resolving the conflict between flexibility and precision through context-aware parameter selection
3Device complexity
If the random access occasion RO positions are not adjusted, then the configuration simplicity is maintained, but the overlap between frequency and time domain positions causes resource conflict
Solution Approach 1:
The patent resolves resource conflicts by adjusting RO positions across multiple dimensions - both frequency domain offsets and time domain shifts are applied. This multi-dimensional positioning allows the system to separate overlapping random access occasions effectively, eliminating resource conflicts while maintaining configuration manageability
Data Source
AI summary
A terminal receives a reference signal from an access network device. The terminal determines, based on a received power of the reference signal and a first set, a quantity of repetition times of sending a random access preamble by the terminal, where the first set is a set of quantities of times of repeatedly sending the random access preamble by the terminal, and the first set includes at least one or more of the following elements: an integer multiple of 3, an integer multiple of 5, or an integer multiple of 7. The terminal repeatedly sends the random access preamble to the access network device on a random access occasion RO based on the quantity of repetition times.