RIS Reflection Control for Side-Lobe and Signal Strength Balance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Reconfigurable Intelligent Surfaces (RISs) in wireless telecommunications face challenges in minimizing side-lobe levels, which lead to energy wastage, interference, reduced signal quality, and coverage area, due to their passive nature and inability to amplify signals.

Innovation Solution

A method for controlling communication devices with reflecting elements that adjusts reflection magnitude and phase based on location, using window functions and controllable units like variable capacitance diodes, to optimize the balance between side-lobe levels and received signal levels, allowing for independent control of reflection magnitude and phase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If uniform reflection magnitude is applied across all reflecting elements, then the main lobe signal strength is maximized, but side-lobe levels increase causing interference and energy wastage

Engineering Contradiction:
Improvemain lobe signal strengthVSAvoidside-lobe interference
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent applies different reflection magnitudes to different reflecting elements based on their positions in the array. Elements at the edges of the array are assigned lower reflection magnitudes compared to central elements, creating a non-uniform distribution that suppresses side-lobes while maintaining main lobe strength. This is achieved through location-based control where each element's reflection coefficient is adjusted according to its spatial coordinates in the array.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If reflection magnitude is reduced at array edges to minimize side-lobes, then side-lobe interference is reduced, but overall received signal level decreases

Engineering Contradiction:
Improveside-lobe interferenceVSAvoidreceived signal level
Core Design Contradiction:
Object-generated harmful factorsVSPower

Solution Approach 1:

The patent changes the reflection magnitude parameter spatially across the array rather than applying a uniform value. By implementing a gradient where central elements have higher reflection magnitudes and edge elements have lower magnitudes, the system achieves an optimal balance between maintaining sufficient received signal power and suppressing side-lobe interference. This parameter variation is controlled based on element location coordinates.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If all reflecting elements are activated uniformly, then coverage area is maximized, but energy wastage increases due to side-lobe radiation

Engineering Contradiction:
Improvecoverage areaVSAvoidenergy wastage
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The patent implements location-dependent control where reflecting elements are selectively activated or deactivated based on their positions in the array. Edge elements may be deactivated or assigned lower reflection magnitudes while central elements remain fully active, creating an effective aperture that reduces side-lobe radiation and energy wastage while maintaining adequate coverage area through the coordinated phase and magnitude control of active elements.

Inventive Principle:
Principle #3Local quality

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 spectral efficiency and signal quality by reducing interference and energy wastage, while maintaining a balance between side-lobe levels and received signal strength, thereby improving the overall performance of wireless communication networks.

Implementation Method 1

A RIS may be defined as a relay that receives an incident signal from an emitter and then re-radiates it in a specific direction

Methodology Applied
Scientific EffectSignal reflection: Reflection

Implementation Method 2

A RIS comprises a large number of reflecting elements that can dynamically tune the phase of the incident signal to improve the performance of radio networks

Methodology Applied
Scientific EffectPhase tuning:

Implementation Method 3

the at least one reflecting element comprises a controllable unit including a variable capacitance diode connected in series or in parallel with a resistor, and controlling the reflection phase comprises varying the capacitance

Methodology Applied
Scientific EffectCapacitance variation: Capacitance

Implementation Method 4

controlling the reflection magnitude comprises varying the resistance of the resistor

Methodology Applied
Scientific EffectResistance variation: Electrical Resistance

Data Source

PatentEP4354751A1Method and device for controling a communication device
Publication Date: 2024.04.17 FOND B COM
  • EP4354751A1 patent drawingFigure 1~2
  • EP4354751A1 patent drawingFigure 3~4
  • EP4354751A1 patent drawingFigure 5A~5B

AI summary

The invention concerns a method for controlling a communication device configured to reflect a signal between an emitter and a receiver, the communication device comprising reflecting elements positioned on a surface of the communication device, the method comprising, at a device: • obtaining data defining an amount of energy to reflect associated to at least one reflecting element, based on the element's location on the surface of the communication device.