Virtual Central Subcarrier Configuration for Inter-Cell Interference Coordination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing communication systems are not backward-compatible with orthogonal transmission or multi-carrier transmission technologies, leading to interference issues and inability to function normally when these advanced methods are employed.

Innovation Solution

A method and device for configuring a central subcarrier by mapping downlink control channels and data channels in a way that aligns frequency domains and subcarriers between cells, using virtual central subcarriers and specific frequency constraints to prevent interference and ensure compatibility with existing systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If orthogonal transmission or multi-carrier transmission is implemented to prevent control channel interference, then control channel receiving performance is improved, but existing communication systems become incompatible and unable to function normally

Engineering Contradiction:
Improvecontrol channel receiving performanceVSAvoidbackward compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a virtual central subcarrier as an intermediary concept that bridges the gap between new communication systems using orthogonal transmission and existing systems. The virtual central subcarrier is a logical construct that allows existing systems to interpret and operate within the new framework without fundamental changes, while enabling the new system to achieve interference coordination benefits

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the central subcarrier frequency parameter by introducing a virtual central subcarrier offset. This parameter change allows the system to maintain the appearance of traditional single-carrier operation for legacy systems while actually implementing multi-carrier or orthogonal transmission in the physical layer, thus achieving both backward compatibility and improved control channel performance

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If downlink control channels are transmitted in different frequency ranges for different cells to achieve orthogonal transmission, then inter-cell interference is reduced, but frequency alignment and resource coordination between cells become more complex

Engineering Contradiction:
Improvecontrol channel interferenceVSAvoidfrequency coordination complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent creates equipotentiality in the frequency domain by establishing a standardized relationship between virtual central subcarriers and physical resource blocks across all cells. By defining that the virtual central subcarrier corresponds to a specific physical resource block (typically the first PRB), the system achieves frequency alignment without requiring complex cell-specific coordination, as all cells operate from the same reference point

Inventive Principle:
Principle #12Equipotentiality

Solution Approach 2:

The patent segments the frequency domain into virtual resource units based on the virtual central subcarrier, which serves as a reference point for allocating physical resource blocks. This segmentation approach allows each cell to independently manage its frequency resources while maintaining overall system coordination through the common virtual reference framework

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2571218B1Method and device for configuring central sub-carrier
Publication Date: 2018.07.11 HUAWEI TECH CO LTD
  • EP2571218B1 patent drawingFigure 1
  • EP2571218B1 patent drawingFigure 2~3
  • EP2571218B1 patent drawingFigure 4

AI summary

A method and a device for configuring a central subcarrier are disclosed. The method comprises: mapping a first downlink control channel onto a part (f1) of a downlink bandwidth (fW) of a cell, and configuring a first virtual central subcarrier in f1, where f1 is different or partly different from a bandwidth f2 mapped to a second downlink control channel, at least one subcarrier is overlapped between f1 and f2, or at least one idle subcarrier exists between f1 and f2, or at least one non-idle subcarrier and at least one idle subcarrier exist between f1 and f2; the first virtual central subcarrier is located on a grid position of a central frequency, a distance between the first virtual central subcarrier and a second virtual central subcarrier configured in f2 is an integer multiple of a frequency domain width of the subcarrier, and borders of physical resource blocks (PRBs) are aligned between the cell and the neighboring cell; and mapping a downlink data channel onto fW of the cell, and configuring a central subcarrier on fW.