Inter-Cell Interference Reduction via Unique Channel Configuration Sets

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Solution Overview

Problem

Wireless communications systems face challenges in accurately estimating channel characteristics due to inter-cell interference, which impairs the effectiveness of interference reduction methods like joint detection and equalization.

Innovation Solution

Assigning unique channel configuration sets, including training sequences, spreading codes, and channel observation windows, to neighboring base stations to differentiate and reduce inter-cell interference, allowing for better detection and mitigation of signal degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If frequency reuse mechanism is implemented to increase spectrum efficiency, then frequency spectrum use efficiency is improved, but inter-cell interference increases

Engineering Contradiction:
Improvefrequency spectrum use efficiencyVSAvoidinter-cell interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the channel observation period into multiple parts, with different base stations observing at different time segments. This temporal segmentation allows neighboring base stations to observe channel characteristics at different times, reducing mutual interference while still enabling accurate channel estimation for each base station.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If training sequence is used to estimate channel characteristics, then channel estimation capability is improved, but estimation accuracy deteriorates due to inter-cell interference

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidinter-cell interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a channel observation window as an intermediary mechanism that isolates the training sequence observation period from interference. By defining specific time windows where only the target base station transmits, the system creates an interference-free environment for channel estimation, acting as a mediator between the training sequence and the channel estimation process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If joint detection or equalization methods are applied to reduce interference, then signal detection performance is improved, but effectiveness deteriorates without accurate channel characteristics

Engineering Contradiction:
Improvesignal detection performanceVSAvoidchannel characteristics accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent performs channel characteristic observation and interference covariance matrix calculation as preliminary actions before applying joint detection or equalization methods. By pre-acquiring accurate channel information through interference-free observation windows, the system prepares the necessary accurate parameters that enable subsequent interference reduction techniques to work effectively.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1889371B1Method and system for interference reduction
Publication Date: 2016.04.13 CISCO TECHNOLOGY INC
  • EP1889371B1 patent drawingFigure 1A~1B
  • EP1889371B1 patent drawingFigure 2~3
  • EP1889371B1 patent drawingFigure 4

AI summary

A method and system for interference reduction for telecommunication systems are disclosed. The system comprises a base station control device (BCD) for configuring one or more parameters for operating one or more base stations (BSs), a first BS covering a first cell having one or more mobile terminals therein, a second BS covering a second cell neighboring to the first cell and sharing a predetermined frequency band with the first cell, wherein one or more radio frames constructed for communications between the first BS and any mobile terminal of the first cell and one or more radio frames constructed for communications between the second BS and any mobile terminal of the second cell are distinguishable by defining different channel configuration sets having one or more operation parameters, wherein the parameters includes a training sequence, a spreading code, and a channel observation window position.