Dynamic CCE Structure for Low Latency Control Signaling

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Solution Overview

Problem

In wireless communication systems, particularly in low latency scenarios, it is challenging to allocate sufficient resources for control signaling within shortened transmission time intervals (sTTIs) due to varying resource elements available for control information transmission, leading to inefficient resource allocation and reduced throughput.

Innovation Solution

The proposed solution involves selecting an appropriate aggregation level or control channel element (CCE) structure for downlink control information (DCI) transmission based on the number of symbols and type of reference signals in the sTTI, allowing for dynamic adjustment of resource allocation to ensure sufficient resources for DCI transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed aggregation level or CCE structure is used for DCI transmission in sTTI, then device complexity is reduced, but resource allocation efficiency deteriorates due to varying resource elements available for control information

Engineering Contradiction:
Improvecontrol channel structureVSAvoidresource allocation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the aggregation level and CCE structure variable rather than fixed. The base station dynamically selects appropriate aggregation levels and CCE structures based on the specific sTTI characteristics (number of resource elements available for control information), allowing the control channel to adapt to varying resource conditions and improve resource allocation efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the control channel structure (aggregation level and CCE structure) based on the number of resource elements available for control information in each sTTI. By adjusting these parameters according to available resources, the system optimizes resource allocation efficiency while maintaining manageable device complexity through standardized selection criteria

Inventive Principle:
Principle #35Parameter changes

2Reliability

If more resources are allocated to control signaling in sTTI, then reliability of DCI transmission is improved, but available resources for data transmission are reduced

Engineering Contradiction:
ImproveDCI transmissionVSAvoiddata transmission resources
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent adjusts the aggregation level parameter based on the number of resource elements available for control information. By changing this parameter dynamically, the system allocates appropriate control signaling resources to ensure reliable DCI transmission while maximizing the remaining resources available for data transmission, thus optimizing the trade-off between reliability and resource quantity

Inventive Principle:
Principle #35Parameter changes

3Productivity

If aggregation level or CCE structure varies based on sTTI characteristics, then resource allocation efficiency is improved, but device complexity increases due to multiple configuration options

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidcontrol channel configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent manages device complexity by systematically changing parameters (aggregation level and CCE structure) based on clearly defined sTTI characteristics, specifically the number of resource elements available for control information. This structured approach allows the system to improve resource allocation efficiency while keeping device complexity manageable through standardized selection criteria rather than arbitrary configurations

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3613166B1Physical downlink control channel structure in low latency systems
Publication Date: 2021.12.15 QUALCOMM INC
  • EP3613166B1 patent drawingFigure 1
  • EP3613166B1 patent drawingFigure 2
  • EP3613166B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. A base station may transmit downlink control information (DCI) to a user equipment (UE) in a control region of a shortened transmission time interval (sTTI) using an aggregation level or control channel element (CCE) structure, which may depend or vary based on characteristics of the sTTI. For instance, the CCE structure or the aggregation may vary based on a type of reference signal and/or on an sTTI index because the sTTI index may correspond to the number of resource elements available for DCI within the sTTI. The control region of the sTTI may include transmissions of cell-specific reference signals (CRSs), demodulation reference signals (DMRSs), or channel state information reference signals (CSI-RSs). The number of resource elements available for DCI within the control region may depend on whether such reference signals are present or on whether CRS-based or DMRS-based demodulation is employed.