5G NR Search Space Allocation for PDCCH Blind Detection Limits

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Solution Overview

Problem

In 5G NR systems, the total quantity of blind detections for UE can exceed the maximum supported PDCCH candidates or channel estimates, especially when multiple TRPs and beams are used, leading to implementation complexity and potential performance issues.

Innovation Solution

A method and device for search space allocation and configuration, where if a TRP is configured for a terminal device, part of the search spaces are discarded if the quantity of PDCCH candidates or non-overlapping CCEs exceeds the monitoring limits, thereby preventing overload and improving resource allocation flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple TRPs and beams are configured for UE to support flexible PDCCH transmission, then transmission reliability and coverage are improved, but the total quantity of blind detections exceeds the maximum supported PDCCH candidates

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidtotal quantity of blind detections

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the search space set into multiple groups, where each group is associated with a specific TRP. By dividing the monitoring tasks across different groups, the system maintains multiple TRP configurations for reliability while organizing blind detections in a structured manner that can be managed within device capabilities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the quantity of PDCCH candidates monitored in each search space group based on device capability parameters. By changing the monitoring parameters adaptively, the system supports multiple TRPs when capability allows while preventing the total blind detections from exceeding maximum supported limits.

Inventive Principle:

Principle #35Parameter changes

2Area of stationary object

If the UE monitors all configured search spaces, then control channel coverage is improved, but the quantity of channel estimates exceeds the maximum quantity of channel estimates

Engineering Contradiction:

Improvecontrol channel coverageVSAvoidquantity of channel estimates

Core Design Contradiction:

Area of stationary objectVSQuantity of substance

Solution Approach 1:

The patent introduces dynamic monitoring where the UE selectively monitors search spaces based on actual scheduling needs and capability status. The monitoring behavior changes dynamically - the UE monitors search spaces when needed for coverage but can skip or reduce monitoring when capability limits are approached, balancing coverage with channel estimate constraints.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements partial monitoring where the UE monitors a subset of configured search spaces rather than all of them simultaneously. By performing partial action (monitoring only necessary search spaces), the system maintains adequate control channel coverage while keeping the quantity of channel estimates within maximum limits.

Inventive Principle:

Principle #16Partial or excessive action

3Device complexity

If the NR system specifies a maximum quantity of PDCCH candidates and channel estimates, then device complexity is reduced, but the flexibility of resource allocation is limited

Engineering Contradiction:

Improveimplementation complexityVSAvoidflexibility of resource allocation

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent performs preliminary configuration of search space groups and their associations with TRPs before actual PDCCH monitoring begins. By pre-organizing the monitoring structure and establishing capability-based parameters in advance, the system simplifies the real-time monitoring process while maintaining flexibility to adapt to different TRP configurations and scheduling scenarios.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a universal search space group structure that can handle multiple TRPs, multiple beams, and different capability scenarios through a single framework. The search space group mechanism serves multiple functions - organizing monitoring, managing TRP associations, and adapting to capability constraints - thereby maintaining flexibility without proportionally increasing complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12284656B2Search space allocation method, search space configuration method, and related device

Publication Date: 2025.04.22 VIVO MOBILE COMM CO LTD

AI summary

The present disclosure provides a search space allocation method, a search space configuration method, and a related device. The method includes: in a case that a TRP is configured for a terminal device, discarding part search spaces configured for the terminal device if a quantity of first monitoring objects in a search space set configured for the terminal device exceeds a limit of first monitoring objects that can be monitored by the terminal device, where the first monitoring object includes a PDCCH candidate or a non-overlapping CCE.