Satellite Interference Suppression via Ground-Extracted Opposition Matrices

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Solution Overview

Problem

Existing multi-spot space communication systems face challenges in suppressing interference signals between geographically neighboring satellite access stations, leading to performance degradation and increased complexity, cost, and payload constraints due to the need for extensive additional equipment and inflexible station location choices.

Innovation Solution

A method and system utilizing an onboard multi-spot communication payload with opposition matrices and remote-controlled attenuators/phase shifters, coupled with ground-based spectrum monitoring and signal processing, to calculate and adjust signal rejection parameters, effectively eliminating interference signals without requiring extensive additional hardware.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional space equipment (opposition matrix, frequency conversion chains, on-board computer) is added to suppress interfering signals, then signal interference suppression capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improveinterference suppression capabilityVSAvoidnumber of additional space equipment
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the interference suppression functionality from the space domain and relocates it to the ground domain. Specifically, the opposition matrix calculation and control signal generation are performed on the ground based on received interference characteristics, while only the essential hardware (reception antenna, frequency conversion chains, and opposition matrix hardware) remains in space. This extraction principle resolves the contradiction by eliminating the need for complex on-board computing and control systems while maintaining interference suppression capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces ground-based monitoring and control systems as intermediaries between the satellite and the interference sources. The ground station receives signals from the satellite, analyzes interference characteristics, calculates opposition matrix parameters, and sends control signals back to adjust the satellite's reception. This intermediary approach allows complex processing to occur on the ground rather than requiring complex space equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If additional space equipment is added for interference suppression, then interference suppression capability is improved, but payload mass and consumption increase

Engineering Contradiction:
Improveinterference suppression capabilityVSAvoidsatellite payload mass
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts the computationally intensive functions (opposition matrix calculation, interference analysis) from the satellite payload and relocates them to ground-based systems. This extraction significantly reduces the mass and power requirements of the satellite payload, as the complex processing is performed on the ground rather than being carried in space.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If spatial spacing between ground stations is increased to greater than twice the beam diameter, then mutual isolation between access stations is improved, but flexibility in station location selection is reduced

Engineering Contradiction:
Improvemutual isolation between access stationsVSAvoidflexibility in station location choice
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter of isolation from being purely spatial (physical distance between stations) to being signal-processing based (electronic isolation through opposition matrix). By using adaptive signal processing techniques that calculate and apply opposition matrices based on actual interference characteristics, the system achieves high isolation ratios without requiring large physical separations between ground stations. This allows operators to select station locations based on infrastructure availability rather than being constrained by spatial spacing requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where ground stations monitor actual interference levels, send this information to the satellite operator, who then adjusts the opposition matrix parameters accordingly. This closed-loop feedback system enables dynamic adaptation to changing interference conditions, maintaining high isolation ratios regardless of the physical spacing between stations.

Inventive Principle:
Principle #23Feedback

4Reliability

If opposition matrix with remote-controlled attenuators and phase shifters is used, then interference rejection is improved, but device complexity and control requirements increase

Engineering Contradiction:
Improveinterference rejection ratioVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the complex control logic and opposition matrix calculation from the space domain and performs it on the ground. The ground-based system receives interference characteristics, calculates the required opposition matrix parameters, and sends simple control signals to adjust the satellite's attenuators and phase shifters. This extraction significantly simplifies the control system architecture by eliminating the need for complex on-board computation and decision-making.

Inventive Principle:
Principle #2Taking out (Extraction)

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 reduces hardware needs, minimizing payload mass, consumption, and dissipation while offering flexibility in satellite access station location choices, ensuring effective interference suppression and maintaining system performance.

Implementation Method 1

calculate the opposition law and apply said law in the opposition matrix in order to suppress interfering signals present on the communication channels of the payload

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP3975434B1System and method for suppressing interfering uplink signals generated inside a spatial system for multi-spot communication
Publication Date: 2024.02.28 THALES SA
  • EP3975434B1 patent drawingFigure 1
  • EP3975434B1 patent drawingFigure 2
  • EP3975434B1 patent drawingFigure 3

AI summary

A method for suppressing interfering signals generated between satellite access stations of a multi-spot communication system is implemented by a distributed air-to-ground subsystem. This subsystem comprises, onboard a multi-spot communication payload, one or more opposition matrices, switches from an input switching set connected to the outputs of the receiving antenna sources, and switches from an output selection ring connected to the upstream outputs of the transmitting antenna sources. On the ground, it includes a GWt satellite access station equipped with a CSM communication spectrum monitoring system and a computer. The suppression method comprises a series of steps (304, 306, 308, 310, 312, 314, 316, 318) for testing the satellite access of the various GW stations, allowing each opposition matrix to be selectively tuned.The multi-spot spatial communication system incorporating the interfering signal suppression subsystem is described.