Shared LTE Control Region Mapping for NR PDCCH in DSS

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Solution Overview

Problem

The integration of 5G NR and 4G LTE networks through dynamic spectrum sharing (DSS) is hindered by limited resource elements available for NR PDSCH due to LTE CRS ports, leading to insufficient resources for NR user equipment as LTE and NR PDCCHs have different processing steps and resource element mappings.

Innovation Solution

A modified LTE control region is introduced to support both LTE and NR PDCCHs, using LTE resource element mapping and CRS pilots, allowing NR PDCCH to be mapped to additional resource elements, thereby expanding the available resources for NR PDSCH.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LTE CRS ports are used in the control region, then LTE PDCCH functionality is maintained, but the number of available resource elements for NR PDSCH is reduced

Engineering Contradiction:

ImproveLTE PDCCH functionalityVSAvoidresource elements for NR PDSCH

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The control region is segmented into different resource element sets: some resource elements are allocated to LTE CRS ports for LTE PDCCH, while other resource elements are allocated to NR PDCCH. This segmentation allows both LTE and NR control channels to coexist in the same control region without fully consuming all resource elements, thereby preserving resources for NR PDSCH.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of resource allocation by implementing separate resource element mappings for LTE and NR PDCCH within the control region. Instead of treating the control region as a single shared space, it creates multiple mapping layers that operate in different resource element dimensions, allowing NR PDCCH to utilize resource elements that would otherwise be exclusively available for data transmission.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If separate control regions are created for LTE and NR PDCCH, then both technologies can operate independently, but device complexity and resource utilization increase

Engineering Contradiction:

Improveindependent operation of LTE and NR PDCCHVSAvoidcontrol region structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the LTE PDCCH and NR PDCCH into a single shared control region rather than creating separate control regions. By combining both control channels in one region and using unified resource element mapping procedures, the system achieves independent operation of LTE and NR PDCCH while avoiding the complexity of maintaining entirely separate control region structures.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control region is designed with universal functionality to support both LTE and NR PDCCH operations. The resource element mapping mechanism is made multi-functional, capable of accommodating both LTE CRS-based mappings and NR mappings within the same control region, thereby eliminating the need for separate dedicated control regions for each technology.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12550150B2Dynamic spectrum sharing physical downlink control channel enhancement

Publication Date: 2026.02.10 QUALCOMM INC

AI summary

A shared control region is provided for enhanced dynamic spectrum sharing between a first radio access technology (e.g., LTE) and a second radio access technology (e.g., NR). The shared control region is resource element mapped according to a resource element mapping for the first radio access technology (RAT) and includes pilot signals for the first RAT. The shared control region also includes control information for a user equipment in the second RAT.