MIMO Antenna Arrangement for Deterministic Orthogonal Channels

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Solution Overview

Problem

In fixed point microwave communication systems, maintaining orthogonality of virtual orthogonal channels is challenging due to the presence of reflected waves and sensitive antenna direction changes, which affect channel capacity and require complex synchronization and feedback mechanisms.

Innovation Solution

The proposed MIMO communication system uses a specific antenna arrangement where transmission and reception antennas are vertically aligned, with geometric parameters set to ensure eigenvalue multiplicity conditions, allowing for orthogonal channel formation without the need for feedback information and independent local oscillators, thus maintaining orthogonality and channel capacity even with reflected waves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If feedback information is used for construction of unitary matrix in SVD method, then channel capacity is maximized and orthogonality is maintained, but system overhead increases and reverse channel is required

Engineering Contradiction:
Improvechannel capacityVSAvoidsystem overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the feedback information requirement from the SVD method by using a specifically designed deterministic antenna arrangement. This arrangement creates inherent orthogonality through geometric configuration (vertical arrangement with specific spacing), allowing the system to achieve maximum channel capacity without the complex feedback mechanism that the invention seeks to remove.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The antenna arrangement itself serves the function of creating orthogonal channels through its geometric configuration. The vertical arrangement with specific spacing relationships causes reflected waves to maintain orthogonality automatically, making the system self-sufficient without requiring external feedback control to maintain channel independence.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If carrier synchronization is achieved between antennas, then MIMO operation is enabled, but severe restrictions are imposed on system construction

Engineering Contradiction:
ImproveMIMO operationVSAvoidsystem construction restrictions
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent removes the requirement for complex carrier synchronization mechanisms by using a deterministic antenna arrangement that creates inherent orthogonality. This extraction of the synchronization requirement simplifies system construction while maintaining MIMO functionality through the geometric configuration of vertically arranged antennas with specific spacing.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3098989B1MIMO communication system having deterministic communication path and antenna arrangement method therefor
Publication Date: 2019.03.06 NEC CORP
  • EP3098989B1 patent drawingFigure 1
  • EP3098989B1 patent drawingFigure 2
  • EP3098989B1 patent drawingFigure 3

AI summary

A MIMO communication system having deterministic channels the orthogonality of which can be ensured even if a reflected wave other than the direct wave is present during line-of-sight communication is provided. The MIMO communication system is used in a line-of-sight environment and has deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged. The transmission side, the reception side, or both transmission and reception sides of the MIMO communication system have a channel matrix calculation processing means for calculating a channel matrix for establishing an orthogonal channel as a communication channel. The transmission and reception antennas forming the channel matrix are horizontally arranged with respect to the ground.