Target-Cell SSB Index Derivation With Timing Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing 5G NR technologies face challenges in deriving SSB indices for inter-frequency neighbor cells with different subcarrier spacings, as the deriveSSB-IndexFromCell flag is not applicable in such scenarios.
Innovation Solution
The method involves receiving SSB information and a flag from a serving cell to allow using the reference cell's timing for deriving the SSB index of a target cell, calculating a tolerance for frame boundary alignment, and determining the SSB index based on this tolerance, even when the subcarrier spacings differ.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the deriveSSB-IndexFromCell flag is used for SSB index derivation, then the SSB index can be derived using reference cell timing, but this approach is not applicable when the inter-frequency target cell has a different subcarrier spacing than the serving cell
Solution Approach 1:
The patent changes the parameter from strict timing alignment to tolerance-based alignment. By calculating a tolerance value (Δt) based on the maximum timing difference between reference cell and target cell SSB bursts, the system allows SSB index derivation to work across different subcarrier spacings. The UE determines whether the absolute timing difference is within the calculated tolerance, and if so, proceeds with SSB index derivation using the reference cell timing.
2Measurement precision
If strict frame boundary alignment is required for SSB index derivation, then timing accuracy is improved, but measurement time increases and scheduling restrictions occur
Solution Approach 1:
Instead of requiring perfect frame boundary alignment, the patent applies partial alignment by introducing a tolerance threshold (Δt). The UE performs SSB index derivation when the timing difference is within this tolerance, which is sufficient for accurate measurement without requiring strict alignment. This reduces measurement time and scheduling restrictions while maintaining adequate timing accuracy for SSB index derivation.
Data Source
AI summary
Disclosed are methods, systems, and computer-readable medium to perform operations including: receiving, by a user equipment (UE) from a serving cell serving the UE, a message comprising: (i) synchronization signal block (SSB) information associated with a target SSB burst of a target cell, and (ii) a flag indicating that the UE is allowed to use timing of a reference cell to derive an index of the target SSB burst, wherein the target SSB burst comprises one or more SSBs; calculating a tolerance of a frame boundary alignment between the reference cell and the target cell; and determining, based on the tolerance, an index of the target SSB burst.