NR Random Access Timing Across Multiple Numerologies
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Solution Overview
Problem
The 3GPP NR system lacks detailed methods for random access channel uplink transmission supporting different numerologies, slot structures, carriers, and transmission of multiple beams, which complicates initial system access and synchronization processes.
Innovation Solution
A wireless device transmits a first random access preamble, determines a time window for monitoring a response, receives a random access response, and prepares for potential retransmission based on subcarrier spacings, allowing efficient uplink transmission timing adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the NR system supports various numerologies and slot structures for different service requirements, then the system's adaptability and versatility are improved, but the device complexity and difficulty of detecting and measuring increase
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting subcarrier spacing values based on different service requirements and channel conditions. The system supports multiple numerologies (different subcarrier spacing values) and allows flexible configuration of random access parameters to adapt to various scenarios while maintaining manageable complexity through standardized procedures.
2Reliability
If the NR system transmits physical signals through multiple beams to overcome poor channel environment, then the reliability is improved, but the device complexity and difficulty of detecting and measuring increase
Solution Approach 1:
The patent applies segmentation by dividing the random access procedure into distinct phases and message exchanges (preamble transmission, random access response, contention resolution). This structured approach to multi-beam transmission allows the system to handle complex beam management through standardized, segmented procedures rather than monolithic complex operations.
Solution Approach 2:
The patent uses parameter changes to adapt beam transmission characteristics based on channel conditions. By dynamically adjusting parameters such as subcarrier spacing, power levels, and timing configurations, the system can optimize reliability in poor channel environments while maintaining manageable detection complexity through standardized parameter sets.
3Ease of manufacture
If detailed methods for random access channel uplink transmission are not defined, then the ease of manufacture is improved, but the measurement precision and transmission timing accuracy deteriorate
Solution Approach 1:
The patent applies preliminary action by pre-defining standardized random access procedures, message formats, and timing relationships before actual deployment. The specification establishes predetermined rules for preamble transmission timing, random access response windows, and contention resolution procedures, ensuring transmission timing accuracy is achieved through pre-planned standardized methods rather than ad-hoc configurations.
Data Source
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AI summary
Provided is a method and apparatus for performing a random access procedure. A wireless device may transmit a random access preamble and may monitor for a random access response. The wireless device may determine to transmit a second random access preamble or to transmit uplink data responsive to the random access response. A time for preparing the second random access preamble may be determined based on a subcarrier spacing associated with the random access preamble or a subcarrier spacing associated a downlink channel associated with the random access response. A time for preparing the uplink data may be determined based on a subcarrier spacing associated with the uplink data or a subcarrier spacing associated a downlink channel associated with the random access response.