Downlink Control Channel Decoding via Hierarchical CCE Reuse

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Solution Overview

Problem

In next-generation 5G wireless communication systems, existing methods for receiving downlink control channels are inefficient due to the need for repeated channel estimation across different aggregation levels, which hampers decoding efficiency.

Innovation Solution

The method involves configuring a search space that allows channel estimation results from a candidate downlink control channel of a lower aggregation level to be reused for decoding a candidate downlink control channel of a higher aggregation level, thereby reducing the need for redundant channel estimation and enhancing decoding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If channel estimation is performed separately for each aggregation level, then decoding accuracy is maintained, but decoding efficiency deteriorates due to redundant estimation operations

Engineering Contradiction:
Improvedecoding efficiencyVSAvoidprocessing time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent performs channel estimation at the lower aggregation level first, before decoding at higher aggregation levels. The channel estimation results obtained from lower aggregation levels are then reused for higher aggregation level decoding, eliminating redundant estimation operations and improving overall decoding efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The channel estimation results obtained from lower aggregation level candidate channels are made universally applicable to higher aggregation level candidate channels. A single channel estimation can serve multiple decoding operations across different aggregation levels, reducing the total number of estimation operations required

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

2Reliability

If repeated channel estimation is performed for each candidate channel, then decoding reliability is improved, but processing complexity increases

Engineering Contradiction:
Improvedecoding reliabilityVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Channel estimation is performed in advance at lower aggregation levels before the actual decoding process at higher aggregation levels. This preliminary estimation creates a reusable resource that simplifies subsequent decoding operations while maintaining reliability through the hierarchical reuse strategy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of discarding channel estimation results after a single use, the patent recovers and reuses these estimation results across multiple aggregation levels. The estimation results are retained and applied to multiple candidate channels, reducing the need for repeated estimation operations

Inventive Principle:
Principle #34Discarding and recovering

Data Source

PatentEP3641195B1Method for receiving downlink control channel and device therefor
Publication Date: 2022.08.10 LG ELECTRONICS INC
  • EP3641195B1 patent drawingFigure 1(A)~1(B)
  • EP3641195B1 patent drawingFigure 2
  • EP3641195B1 patent drawingFigure 3

AI summary

A method by which a terminal receives a downlink control channel in a wireless communication system is disclosed. Particularly, the method monitors candidate physical downlink control channels (PDCCHs) composed of control channel elements (CCEs), the number of which corresponds to an aggregation level, so as to receive a PDCCH, wherein CCEs for candidate PDCCHs of a higher aggregation level include all of the CCEs for candidate PDCCHs of a lower aggregation level, and the CCEs for candidate PDCCHs of the lower aggregation level included in each of the candidate PDCCHs of the higher aggregation level can be determined using a matrix on the basis of the magnitude of the higher aggregation level and the number of the candidate PDCCHs of the higher aggregation level.