Satellite Terminal Spectrum Inversion for LEO-GEO Interference Avoidance

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Solution Overview

Problem

Current low earth orbit (LEO) and geosynchronous earth orbit (GEO) satellite systems face interference issues due to operating in the same frequency bands, leading to constraints on aperture and reliability, especially in hilly or forested areas.

Innovation Solution

The solution involves reversing the spectrum configuration for LEO satellite systems, allowing them to operate on the same frequencies as GEO systems without interference, by using higher millimeter wave frequencies to create narrow pencil-beams and forming nulls to reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If LEO and GEO satellite systems operate in the same frequency bands, then spectrum utilization is improved, but interference between systems increases

Engineering Contradiction:

Improvespectrum utilizationVSAvoidinterference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the traditional frequency assignment approach by assigning higher frequencies to LEO uplink and lower frequencies to GEO downlink, rather than using the conventional configuration. This spectral inversion, combined with reversed diplexing, creates frequency separation that eliminates interference while allowing both systems to operate simultaneously in what would otherwise be overlapping bands

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces a new dimension of frequency management by implementing reversed diplexing configuration, where the uplink and downlink frequency relationships are inverted compared to traditional systems. This creates an additional degree of freedom in spectrum management, allowing LEO and GEO systems to coexist without interference by operating in effectively different frequency dimensions

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If LEO systems use conventional frequency configuration, then ease of implementation is improved, but aperture constraints and reliability deteriorate

Engineering Contradiction:

Improveease of implementationVSAvoidreliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the frequency parameters of the LEO satellite system by assigning higher millimeter wave frequencies to LEO uplink and lower frequencies to downlink. This parameter change enables the system to overcome aperture constraints and improve reliability in challenging environments such as hilly or forested areas, while maintaining implementation feasibility through systematic frequency reconfiguration

Inventive Principle:

Principle #35Parameter changes

3Reliability

If LEO systems transmit with higher power to overcome terrain obstacles, then communication reliability is improved, but interference to GEO satellites increases

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidinterference to GEO satellites

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the frequency assignment to place LEO uplink in higher frequency bands and GEO downlink in lower frequency bands. This spectral inversion creates automatic frequency separation that prevents LEO transmissions from interfering with GEO satellites, eliminating the need to reduce transmission power while maintaining communication reliability

Inventive Principle:

Principle #13The other way round (Inversion)

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 enables LEO systems to communicate directly overhead at all latitudes without impacting GEO satellite operations, providing more robust interference protection and increased reliability, especially in challenging terrain.

Implementation Method 1

using higher millimeter wave frequencies to create narrow pencil-beams

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

forming nulls to reduce interference

Methodology Applied

Scientific EffectAntenna radiation pattern control: Electromagnetic Induction

Data Source

PatentUS20250132814A1Terminal with interference avoidance between satellite systems using common spectrum

Publication Date: 2025.04.24 LOGOS SPACE SERVICES INC

AI summary

A satellite communication system includes a first frequency reference generator of a terminal, a broadband communication receiving channel, a second frequency reference generator of the terminal, and a broadband communication transmission channel. The first frequency reference generator generates a first frequency reference signal in a first frequency band. The broadband communication receiving channel for receiving broadband data at the terminal using the first frequency reference signal, wherein a legacy satellite system comprises a legacy communication transmission channel for transmitting data from a legacy satellite in the first frequency band. The second frequency reference generator generates a second frequency reference signal in a second frequency band. The broadband communication transmission channel for transmitting broadband data from the terminal using the second frequency reference signal, wherein the legacy satellite system comprises a legacy communication receiving channel for receiving data at the legacy satellite using the second frequency band.