IAB DU Resource Configuration for Paired Spectrum Allocation

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Solution Overview

Problem

Existing IAB networks face challenges in efficiently managing resource allocation for paired spectrum, particularly in FDD carriers, where separate configurations for uplink and downlink are needed but current frameworks lack sufficient flexibility and dynamic adjustment.

Innovation Solution

A per-cell DU resource configuration framework is introduced for FDD carriers, allowing two semi-static configurations per cell, with symbol patterns and availability attributes for each symbol type, enabling flexible use of soft symbols and explicit release by a parent IAB node.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If IAB uses unpaired spectrum for uplink and downlink, then implementation is simpler and interference management is easier, but spectrum utilization is inefficient and available resources are limited

Engineering Contradiction:
Improveimplementation simplicityVSAvoidspectrum utilization efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent divides the paired spectrum into separate uplink and downlink portions, allowing IAB to utilize both while managing interference through specific techniques. The spectrum is segmented into frequency range 1 for downlink and frequency range 2 for uplink, enabling efficient resource allocation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism where the IAB node performs full-duplex communications with both the donor node and the UE simultaneously. This intermediary role allows the IAB to bridge communications while managing the complexity of paired spectrum utilization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If IAB uses paired spectrum for uplink and downlink, then spectrum utilization efficiency improves and available resources increase, but implementation complexity increases and interference management becomes more difficult

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidimplementation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by configuring different numerologies for uplink and downlink transmissions. Specifically, a first subcarrier spacing is configured for downlink and a second subcarrier spacing for uplink, optimizing each direction's transmission characteristics while managing interference locally at the IAB node.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces dynamic switching capabilities where the IAB node can switch between different operating modes (full-duplex, half-duplex) and adjust numerology configurations based on traffic conditions and interference levels, making the system adaptable rather than static.

Inventive Principle:
Principle #15Dynamics

3Productivity

If IAB performs full-duplex communications in paired spectrum, then uplink and downlink transmissions can occur simultaneously improving efficiency, but self-interference and interference to/from donor node and UE increase

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidself-interference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes key transmission parameters including subcarrier spacing, cyclic prefix lengths, and time resource allocations to mitigate interference. By adjusting these parameters dynamically, the system optimizes full-duplex operation while reducing self-interference and interference to other links.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary actions by pre-configuring interference mitigation measures before full-duplex transmission begins. This includes pre-calculating reference signal configurations, setting up interference cancellation algorithms, and establishing resource allocation patterns that prevent interference issues before they occur.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4133852B1Support of IAB operation in paired spectrum
Publication Date: 2026.04.29 QUALCOMM INC
  • EP4133852B1 patent drawingFigure 1
  • EP4133852B1 patent drawingFigure 2
  • EP4133852B1 patent drawingFigure 3

AI summary

Aspects relate to an integrated access backhaul (IAB)-Distributed Unit (DU) resource configuration framework for paired (e.g., frequency division duplex (FDD)) spectrum. Two DU resource configurations per cell may be supported for paired spectrum, including one for a first spectrum band (e.g., a downlink frequency band) and another for a second spectrum band (e.g., an uplink frequency band) of the paired spectrum. Each DU resource configuration may include a respective symbol pattern of symbol types (e.g., downlink (DL), uplink (UL), flexible) for a plurality of slots, as well as a corresponding availability attribute for each symbol type (e.g., hard, soft, or not available). A DU of an IAB node in an IAB network may receive the two DU resource configurations for the paired spectrum from a central unit (CU) of an IAB donor node in the IAB network.