NR-U PDCCH Blind Decoding for Dynamic LBT Sub-Bands

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Solution Overview

Problem

In NR-U systems with multiple 20MHz bands, LBT based on 20MHz measurement units lead to dynamic changes in available bands, causing potential service failures and increased power consumption due to unnecessary blind decodings on all RRC configured PDCCH resources.

Innovation Solution

A method for a UE to perform blind decoding only on PDCCH resources indicated by a first-type radio signal, dynamically adjusting according to LBT results, ensuring sufficient PDCCH resources and reducing unnecessary decodings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE monitors all RRC configured PDCCH resources for blind decoding, then the PDCCH resources are sufficient to ensure service continuity, but the UE power consumption increases and processing complexity rises

Engineering Contradiction:
Improveservice continuityVSAvoidUE power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the PDCCH monitoring behavior adaptive rather than static. The UE dynamically adjusts which PDCCH resources to monitor based on LBT outcomes received from the network. When LBT succeeds on certain sub-bands, the UE monitors PDCCH on those sub-bands; when LBT fails, the UE skips monitoring on those sub-bands. This dynamic adjustment resolves the contradiction by maintaining service reliability through selective monitoring while reducing power consumption by avoiding unnecessary monitoring on unavailable sub-bands.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of PDCCH monitoring configuration based on LBT results. The network signals to the UE which sub-bands are available through LBT, and the UE changes its monitoring parameters accordingly. Instead of monitoring all configured PDCCH resources uniformly, the UE modifies its monitoring behavior to match the actual available spectrum resources, thereby reducing power consumption while maintaining service continuity on available sub-bands.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the UE performs blind decoding on all configured PDCCH resources, then no service failure occurs due to LBT failures, but the UE processing complexity increases

Engineering Contradiction:
Improveservice availabilityVSAvoidUE processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the PDCCH monitoring configuration dynamic based on real-time LBT outcomes. The UE receives signaling from the network indicating which sub-bands have successfully passed LBT, and accordingly adjusts its blind decoding operations only to those sub-bands. This dynamic approach ensures service availability on available sub-bands while significantly reducing processing complexity by eliminating blind decoding attempts on sub-bands that are currently unavailable due to LBT failures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent extracts the unnecessary blind decoding operations from the UE's processing workload. By receiving LBT outcome information from the network, the UE can identify and remove (extract) the PDCCH monitoring tasks on sub-bands that are currently unavailable. This leaves only the essential blind decoding operations on available sub-bands, thereby reducing processing complexity while maintaining service availability where possible.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the system configures PDCCH resources on each 20MHz band to adapt to dynamic band availability, then service continuity is maintained, but the signaling overhead increases

Engineering Contradiction:
Improveservice continuityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies universality by using a single LBT outcome signaling mechanism that serves multiple purposes. The network signals LBT results for multiple sub-bands using a unified approach, and this single signaling operation enables the UE to adjust its PDCCH monitoring across all affected sub-bands. This multi-functional signaling reduces overhead compared to separate signaling for each sub-band while maintaining service continuity through comprehensive band availability information.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3849264B1Method for and apparatus in user equipment for wireless communication, and method for and apparatus in base station for wireless communication
Publication Date: 2025.09.24 APOGEE NETWORKS LLC
  • EP3849264B1 patent drawingFigure 1~3
  • EP3849264B1 patent drawingFigure 4~5
  • EP3849264B1 patent drawingFigure 6~9

AI summary

Disclosed are a method for and an apparatus in a user equipment for wireless communication, and a method for and an apparatus in a base station for wireless communication. The method for a user equipment for wireless communication comprises: a user equipment receiving first information, wherein the first information is used for indicating M instances of DCI blind decoding; in a first time-domain resource, respectively monitoring a first type of wireless signals on each sub-band from among S sub-bands; and in the first time-domain resource, at most executing, on the S sub-bands, M1 instances of DCI blind decoding from among the M instances of DCI blind decoding, wherein the first type of wireless signals detected on the S sub-bands are used for determining the M1 instances of DCI blind decoding from the M instances of DCI blind decoding. The method allows a base station to dynamically adjust blind decoding of a UE side on a PDCCH resource according to a result of LBT, thereby ensuring enough PDCCH resources and also avoiding the PDCCH resources excessively occupying PDSCH resources, and avoiding excessive instances of blind decoding.