Downlink Control Channel Symbol Mapping for Nested Aggregation Levels

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Solution Overview

Problem

In wireless communication systems, the existing techniques for transmitting downlink control information in a search space using different aggregation levels are deficient, leading to ambiguity and incorrect identification by user equipment (UE), resulting in reduced throughput due to nested aggregation levels where control information is mistakenly identified as being transmitted using a different aggregation level.

Innovation Solution

The method involves mapping modulated control symbols to resource element groups (REGs) or resource elements (REs) differently based on the aggregation level, including interleaving and out-of-order mapping for various aggregation levels, to ensure correct identification of the control channel by the UE, even when aggregation levels are nested.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the same mapping method is used for all aggregation levels, then the implementation is simple, but the user equipment cannot correctly identify the control channel when aggregation levels are nested

Engineering Contradiction:
Improvecontrol channel identification accuracyVSAvoidmapping method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by using different mapping methods for different aggregation levels. Specifically, aggregation level 1 uses a first mapping method while aggregation levels 2, 4, and 8 use a second mapping method. This allows the system to optimize for control channel identification accuracy in nested scenarios without requiring all aggregation levels to use complex differentiating mappings, thus resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #3Local quality

2Reliability

If different mapping methods are used for all aggregation levels to prevent ambiguity, then the control channel identification accuracy improves, but the implementation complexity increases

Engineering Contradiction:
Improvecontrol channel identification accuracyVSAvoidmapping method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements local quality by applying different mapping strategies to different aggregation levels based on their specific needs. Aggregation level 1 uses a first mapping method while levels 2, 4, and 8 use a second mapping method. This targeted approach prevents ambiguity in nested aggregation level scenarios without requiring all levels to use complex differentiated mappings, thus resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If nested aggregation levels are supported, then the system flexibility improves, but the user equipment may mistakenly identify control information transmitted at one aggregation level as being transmitted at another aggregation level

Engineering Contradiction:
Improveaggregation level support flexibilityVSAvoidcontrol information identification accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent resolves this contradiction by applying different mapping methods to different aggregation levels. Aggregation level 1 uses a first mapping method while levels 2, 4, and 8 use a second mapping method. This allows the system to maintain flexibility in supporting nested aggregation levels while preventing misidentification through localized mapping differentiation where it is most needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses mapping method differentiation as a form of 'color change' to distinguish between aggregation levels. By assigning different mapping patterns (analogous to different colors) to different aggregation levels, the system enables user equipment to reliably identify the correct aggregation level even when nested levels are present, thus maintaining both flexibility and reliability.

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP4304125A1Symbol mapping for a downlink control channel
Publication Date: 2024.01.10 QUALCOMM INC
  • EP4304125A1 patent drawingFigure 1
  • EP4304125A1 patent drawingFigure 2
  • EP4304125A1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. An apparatus for wireless communication may receive a plurality of modulated control symbols over interleaved resources of an aggregation level candidate on a downlink control channel, de-interleave the resources based at least in part on an aggregation level associated with the downlink control channel, and decode the plurality of modulated control symbols into control information. Alternatively, the apparatus for wireless communication may receive a plurality of modulated control symbols interleaved over resources of an aggregation level candidate on a downlink control channel, de-interleave the plurality of modulated control symbols based at least in part on an aggregation level associated with the downlink control channel, and decode the plurality of modulated control symbols into control information.