EPDCCH Resource Indexing for Mixed PDCCH Subframes

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently identifying and managing uplink channel resources for HARQ feedback information, particularly in mixed scenarios with both PDCCH and EPDCCH within the same association set of downlink subframes, leading to complexities in determining CCE and ECCE indices for PUCCH resource allocation.

Innovation Solution

The system monitors downlink control messages in a set of subframes, determines an index for enhanced control channel elements (ECCEs) based on the total number of subframes, and uses this index to identify uplink control channel resources for transmitting ACK/NACK indications, allowing continuous or selective indexing across each subframe regardless of EPDCCH configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate indexing methods are used for PDCCH and EPDCCH in mixed scenarios, then resource allocation flexibility is improved, but system complexity and difficulty in determining CCE and ECCE indices increases

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the separate indexing procedures for PDCCH and EPDCCH into a unified indexing method. By treating both control channel types using the same CCE indexing approach, the system maintains resource allocation flexibility for different channel types while eliminating the complexity of maintaining separate indexing logic, thus resolving the contradiction between adaptability and system complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies a universal indexing mechanism that works for both PDCCH and EPDCCH regardless of their specific configurations. The same CCE index determination rules are used universally across different control channel types and association sets, providing flexibility through configuration while simplifying the system by eliminating the need for type-specific indexing procedures

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

2Ease of operation

If continuous indexing across all subframes is implemented, then resource management is simplified, but resource utilization efficiency may be reduced due to ignoring PDCCH-only subframes

Engineering Contradiction:
Improveresource management simplicityVSAvoidresource utilization efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent changes the indexing parameter scope to include all downlink subframes regardless of their control channel type. By continuously incrementing CCE indices across all subframes in the association set rather than resetting or skipping PDCCH-only subframes, the system achieves simpler resource management through unified indexing while maintaining efficient resource utilization through continuous index progression

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If separate handling of PDCCH and EPDCCH indexing is performed, then accuracy in resource identification is improved, but operational complexity and potential for errors increases

Engineering Contradiction:
Improveresource identification accuracyVSAvoidoperational complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent segments the association set into individual subframes and processes each subframe through the same standardized CCE indexing procedure. This segmentation approach maintains accurate resource identification by treating each subframe independently with consistent rules, while reducing operational complexity by eliminating the need for complex conditional logic to differentiate between PDCCH and EPDCCH handling

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2921014B1Pucch resource determination for epdcch
Publication Date: 2020.04.29 QUALCOMM INC
  • EP2921014B1 patent drawingFigure 1
  • EP2921014B1 patent drawingFigure 2
  • EP2921014B1 patent drawingFigure 3

AI summary

Methods, systems, and devices are described for indexing control channel elements to determine uplink channel resources. Downlink control messages may be monitored in a set of downlink subframes. The monitoring may include monitoring physical downlink control channel (PDCCH) messages in at least one of the subframes and monitoring enhanced physical downlink control channel (EPDCCH) messages in at least one of the subframes. A downlink control message may be received in at least one subframe. The downlink control message may include an EPDCCH message. An index for enhanced control channel elements (ECCEs) may be determined based at least in part on the set of downlink subframes. The determined index of the ECCEs may be used to identify uplink control channel resources. The ECCEs may be indexed in a manner that is specific to a cell in a wireless communication system, or which is configured for a particular mobile device.