OAM Mode Multiplexing With Dynamic Weighting For Wireless Antennas

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Solution Overview

Problem

The directivity of antennas in wireless communication devices is reduced as the absolute value of orbital angular momentum (OAM) mode increases, limiting the reception power and the number of OAM modes that can be multiplexed for higher throughput.

Innovation Solution

A wireless communication device and method that modulate signals into multiple OAM modes with real values and calculate weighting factors based on the wireless environment to multiplex signals across multiple antenna elements, allowing for a larger number of OAM modes to be used without increasing beam spreading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If electromagnetic waves in multiple OAM modes are multiplexed to increase transmission capacity, then throughput is improved, but antenna directivity is reduced and reception power decreases

Engineering Contradiction:
ImprovethroughputVSAvoidreception power
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent applies dynamic beamforming by calculating weighting factors for each antenna element based on the wireless environment (channel state information). This allows the system to dynamically adjust the beam pattern to maintain directivity toward the reception side even when multiple OAM modes are multiplexed, thereby resolving the contradiction between increased throughput and maintained reception power

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of OAM mode selection to include fractional modes (e.g., 0.5, 1.5, 2.5) in addition to integer modes. This parameter expansion allows for more multiplexing opportunities while the calculated weighting factors compensate for the directivity loss, enabling both higher throughput and adequate reception power

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the number of OAM modes used for multiplexing is increased to improve data transmission capacity, then throughput is enhanced, but the beam spreading increases and directivity is reduced

Engineering Contradiction:
Improvedata transmission capacityVSAvoidbeam spreading
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system dynamically calculates optimal weighting factors for each antenna element based on real-time wireless environment information. This dynamic adjustment compensates for the beam spreading effect that occurs when multiple OAM modes are multiplexed, maintaining focused beam directivity while enabling higher data transmission capacity through increased mode multiplexing

Inventive Principle:
Principle #15Dynamics

3Productivity

If integer OAM modes are used for multiplexing, then spatial multiplexing is achieved, but the number of usable modes is limited compared to fractional modes

Engineering Contradiction:
Improvemultiplexing capacityVSAvoidOAM mode selection flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent extends the OAM mode parameter from discrete integer values to continuous fractional values (e.g., 0.5, 1.5, 2.5). This parameter expansion significantly increases the available modes for multiplexing, enhancing both multiplexing capacity and system adaptability. The calculated weighting factors ensure that these additional fractional modes can be effectively utilized without compromising beam directivity

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances throughput by enabling the multiplexing of a greater number of OAM modes, improving data transmission capacity while maintaining antenna directivity, thereby increasing reception power and efficiency.

Implementation Method 1

a modulation unit modulating signals including data in a plurality of first orbital angular momentum (OAM) modes where the plurality of first orbital angular momentum, OAM, modes are real values different from each other

Methodology Applied
Scientific EffectOrbital Angular Momentum (OAM): Angular Momentum

Implementation Method 2

a transmission processing unit multiplexing each of the signals in the plurality of first OAM modes for each of the plurality of antenna elements by using the factors

Methodology Applied
Scientific EffectElectromagnetic wave multiplexing:

Data Source

PatentEP3691151B1Wireless communication device and wireless communication method
Publication Date: 2022.06.22 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3691151B1 patent drawingFigure 1
  • EP3691151B1 patent drawingFigure 2(a)~2(b)
  • EP3691151B1 patent drawingFigure 3(a)~3(b)

AI summary

A wireless communication device includes a plurality of antenna elements; a modulation unit modulating signals including data in a plurality of first OAM modes having different real number values; a calculation unit calculating factors indicating weights corresponding to each of the signals in the plurality of first OAM modes modulated by the modulation unit for each of the plurality of antenna elements, based on information indicating a wireless environment of a counter wireless communication device that is a transmission destination of the data; and a transmission processing unit multiplexing each of the signals in the plurality of first OAM modes for each of the plurality of antenna elements by using the factors, and outputting the signals obtained through multiplexing for each of the plurality of antenna elements to each of the plurality of antenna elements.