Random Access Identifier Computation for High Subcarrier Spacing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication networks face challenges in performing random access with subcarrier spacings higher than 120 kHz and accommodating multiple subcarrier spacings within the same cell, leading to difficulties in distinguishing between random access channel attempts by different devices.
Innovation Solution
A wireless communication device computes a random access identifier associated with a random access channel occasion as a function of the index of the first slot in a system frame, allowing for subcarrier spacings greater than 120 kHz and enabling the selection of appropriate subcarrier spacing for random access, thereby supporting higher subcarrier spacings and multiple spacings in the same cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If known approaches to random access are used, then random access is supported up to 120 kHz subcarrier spacing, but random access fails when subcarrier spacing is higher than 120 kHz because RA-RNTI cannot distinguish between multiple random access channel attempts
Solution Approach 1:
The patent changes the parameters used to compute RA-RNTI by introducing a reference subcarrier spacing (120 kHz) that is different from the actual subcarrier spacing of the random access channel occasion. This allows the system to support higher subcarrier spacings (240 kHz, 480 kHz, 960 kHz) while maintaining reliable random access identification through the modified RA-RNTI computation formula that accounts for the reference slot index rather than the actual slot index at the higher subcarrier spacing.
2Adaptability or versatility
If known approaches are used, then the system works with a single subcarrier spacing, but multiple subcarrier spacings cannot be accommodated in the same cell
Solution Approach 1:
The patent implements a universal random access mechanism that can handle multiple subcarrier spacings (120 kHz, 240 kHz, 480 kHz, 960 kHz) within the same cell by using a reference subcarrier spacing of 120 kHz for RA-RNTI computation. This multi-functional approach allows the system to accommodate different subcarrier spacings without requiring separate random access procedures for each spacing, thereby managing complexity while enhancing adaptability.
3Ease of operation
If the slot index is used directly for RA-RNTI computation at higher subcarrier spacings, then the computation is simple, but multiple random access attempts cannot be distinguished
Solution Approach 1:
The patent introduces a reference slot index based on a reference subcarrier spacing of 120 kHz as an intermediary for RA-RNTI computation. Instead of using the actual slot index at higher subcarrier spacings directly, the system computes the RA-RNTI based on the reference slot index, which serves as a mediator that preserves the ability to distinguish between multiple random access attempts while simplifying the computation through a standardized reference framework.
Data Source
AI summary
A wireless communication device (12) computes a random access identifier (20) associated with a random access channel occasion (18). The wireless communication device (12) in particular computes the random access identifier (20) as a function of an index of the first slot (32) of the random access channel occasion (18) in a system frame (24). In some embodiments, the subcarrier spacing used to determine the index (30) is different than a subcarrier spacing of the random access channel occasion (18). Regardless, the wireless communication device (12) transmits a random access message (16) using the random access channel occasion (18) and the computed random access identifier (20).