LTE/NR RB Utilization Calculation Across Misaligned Grids

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Solution Overview

Problem

The differing numbers of resource blocks (RBs) for LTE and NR in a given bandwidth cause ambiguity in calculating RB utilization during spectrum sharing, leading to inaccuracies in existing methods.

Innovation Solution

Determine the number of available RBs based on the RB grid and resource split for a given slot, considering the misalignment between LTE and NR RBs above the DC subcarrier, using various options for RB allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If spectrum sharing is implemented between LTE and NR, then spectrum utilization efficiency is improved, but RB grid misalignment causes ambiguity in calculating available RBs

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidRB utilization calculation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the frequency spectrum into distinct LTE and NR regions within the same bandwidth. By dividing the total RBs into LTE RBs and NR RBs based on the RB grid structure, the system can accurately calculate available RBs for each technology separately while maintaining overall spectrum sharing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different RB counting methods to different frequency regions. Below the DC subcarrier, LTE and NR RBs are aligned and counted together. Above the DC subcarrier, the patent accounts for the misalignment by adjusting the NR RB count, applying local quality treatment to resolve the measurement ambiguity in different spectrum regions.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If NR RBs are counted above DC subcarrier, then NR resource allocation is improved, but LTE RB count becomes inaccurate due to misalignment

Engineering Contradiction:
ImproveNR resource allocation flexibilityVSAvoidLTE RB utilization measurement
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies different counting approaches to different frequency regions. Above the DC subcarrier, where misalignment occurs, the patent adjusts the NR RB count to account for the shifted LTE RBs, thereby maintaining measurement precision for both technologies simultaneously.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of trying to align LTE and NR RBs perfectly, the patent inverts the approach by explicitly calculating the misalignment offset and using it to adjust the NR RB count. This inversion of the alignment problem into a calculable offset resolves the measurement ambiguity.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If dynamic RB allocation is implemented, then spectrum sharing efficiency is improved, but calculation complexity increases

Engineering Contradiction:
Improvespectrum sharing efficiencyVSAvoidRB utilization calculation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent performs preliminary calculation of the misalignment offset based on the known RB grid structures and DC subcarrier position. By pre-calculating this offset, the system simplifies the dynamic RB allocation process during operation, reducing real-time calculation complexity while maintaining scheduling flexibility.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4229806B1Resource block utilization calculation for spectrum sharing
Publication Date: 2025.09.24 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4229806B1 patent drawingFigure 1~4
  • EP4229806B1 patent drawingFigure 5~11
  • EP4229806B1 patent drawingFigure 12~18

AI summary

A method performed by a network device processor to determine a number of available resource blocks, RBs, in a time slot of a spectrum of a given bandwidth includes determining (2201) whether or not the slot is assigned to LTE and NR. The method includes responsive (2601) to the slot being assigned to LTE and NR and starts from a low frequency with NR and ends at a high frequency with LTE, and the RB segment at a lowest spectrum part assigned to NR and the RB segment at a highest spectrum part assigned to LTE: responsive (2603) to a number m of LTE segments crossing or above a DC subcarrier, determining that the number of available RBs in the slot is A+p-(m-1), or B-p-(m-1), where A and B are LTE and NR cell channel bandwidth, respectively, and p is the number based on a cell channel bandwidth.