Differential Cyclic Delay Diversity MIMO for Inter-Cell Interference

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Solution Overview

Problem

Femto cells and macro cells experience significant inter-cell interference due to their coexistence, which is exacerbated by the inability of femto cells to perform cell planning and their indoor installation, leading to increased interference and near-far problems.

Innovation Solution

A transmitting/receiving apparatus and method that determines whether a terminal is in a femto cell or macro cell region to differentially apply cyclic shift values, generating delay signals with specific phase or time differences to reduce interference by optimizing signal timing and reception zones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If femto cells are installed indoors without cell planning, then ease of installation and user flexibility are improved, but inter-cell interference with macro cells worsens

Engineering Contradiction:

Improveease of installationVSAvoidinter-cell interference

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies different cyclic shift values based on the terminal's location (femto cell region or macro cell region). By determining whether the terminal is in a femto cell or macro cell region and setting corresponding cyclic shift values, the system creates location-specific signal characteristics that reduce inter-cell interference while maintaining the flexibility of indoor femto cell installation.

Inventive Principle:

Principle #3Local quality

2Device complexity

If cyclic shift values are uniformly applied to all terminals, then device complexity is reduced, but inter-cell interference increases

Engineering Contradiction:

Improvecomplexity of cyclic shift configurationVSAvoidinter-cell interference

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent dynamically determines the appropriate cyclic shift value based on the terminal's current location. The system includes a terminal location determiner that identifies whether the terminal is in a femto cell or macro cell region, and a cyclic shift value setting unit that selects the appropriate cyclic shift value accordingly. This dynamic adaptation reduces inter-cell interference without requiring complex manual configuration.

Inventive Principle:

Principle #15Dynamics

3Object-affected harmful factors

If differential cyclic shift values are applied based on terminal location, then inter-cell interference is reduced, but the complexity of determining terminal location and setting appropriate values increases

Engineering Contradiction:

Improveinter-cell interferenceVSAvoidcomplexity of location determination and cyclic shift configuration

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system automatically determines the terminal's location and selects the appropriate cyclic shift value without requiring manual intervention. The terminal location determiner and cyclic shift value setting unit work autonomously to identify the terminal's region and configure the appropriate parameters, reducing the need for complex manual setup while minimizing inter-cell interference.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8892122B2Transmitting and receiving apparatuses and methods using a differential cyclic delay diversity MIMO scheme

Publication Date: 2014.11.18 PANTECH CORP

AI summary

Disclosed are a transmitting/receiving apparatus and method using a differential cyclic delay diversity MIMO scheme.