Dynamic Aggregation Level Determination for Downlink Control Channels

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Solution Overview

Problem

In wireless communication systems, the existing LTE design restricts downlink control channel transmission to PRB pairs with the same number of resource elements, leading to ambiguity in supported sizes of candidate control channel signals when PRB pairs have different available resources, affecting code rate and resource utilization.

Innovation Solution

A method for transmitting downlink control channels within a set of PRB pairs with varying resource elements, where the radio network node allocates PRB pairs and determines supported aggregation levels based on available resources, discarding positions with excessive code rates for higher aggregation levels to ensure efficient multiplexing and decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If PRB pairs with different numbers of resource elements are used for downlink control channel transmission, then spectral utilization and resource efficiency are improved, but ambiguity in supported sizes of candidate control channel signals arises

Engineering Contradiction:
Improvespectral utilizationVSAvoidambiguity in supported sizes
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent changes the parameter of aggregation level determination from fixed to dynamic. The network node determines the set of supported aggregation levels based on the actual number of resource elements available in each PRB pair, allowing adaptation to varying resource conditions while maintaining unambiguous control channel transmission

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system transitions from static aggregation level configuration to dynamic determination. The set of supported aggregation levels is determined adaptively based on the specific resource element availability in allocated PRB pairs, enabling the system to respond to changing resource conditions without creating ambiguity

Inventive Principle:
Principle #15Dynamics

2Reliability

If PRB pairs with the same number of resource elements are used for downlink control channel transmission, then unambiguous aggregation level determination is maintained, but resource utilization efficiency decreases

Engineering Contradiction:
Improveunambiguous aggregation level determinationVSAvoidresource utilization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the determination criterion from fixed resource element counts to dynamic assessment of available resources. By determining supported aggregation levels based on actual resource element availability in each PRB pair, the system maintains reliability through systematic determination while improving resource utilization

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the downlink frequency carrier into multiple PRB pairs that can be independently allocated and assessed. Each PRB pair's resource element availability is evaluated separately, allowing flexible combination of PRB pairs with different resource characteristics while maintaining overall system reliability

Inventive Principle:
Principle #1Segmentation

3Reliability

If positions with excessive code rates are discarded for higher aggregation levels, then transmission reliability is improved, but the number of available transmission positions decreases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidnumber of available transmission positions
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the code rate threshold from a fixed constraint to a dynamic parameter. The threshold is determined based on the specific aggregation level and resource availability, allowing positions to be retained or discarded adaptively. This maintains reliability by applying appropriate thresholds while preserving more transmission positions than fixed constraints would allow

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2946514B1Methods and nodes in a wireless communication system
Publication Date: 2020.03.11 HUAWEI TECH CO LTD
  • EP2946514B1 patent drawingFigure 1
  • EP2946514B1 patent drawingFigure 2
  • EP2946514B1 patent drawingFigure 3

AI summary

Methods(300, 500) and nodes (110, 120) for transmission of downlink control channel signals in a downlink frequency carrier of a wireless communication system (100), wherein at least two PRB pairs, configurable for the transmission of a downlink control channel have different numbers of time-frequency resource elements available for the transmission of said downlink control channel. The method (300) comprises allocating (301) at least one set (S) of PRB pairs; arranging (302) time-frequency resource elements from said set (S) into an aggregation comprising at least one level; determining (303) a set (LS) of aggregation levels supported for the transmission of a downlink control channel within the allocated (301) set of PRB pairs, based on the number of time-frequency resource elements available for the transmission of a downlink control channel in PRB pairs of the set (S); and transmitting (304) the downlink control channel within said set (S) of PRB pairs.