Combined Satellite Terrestrial Communication Frequency Interference

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Combined satellite and terrestrial communication systems face interference issues due to shared frequency spectrum, leading to inefficiencies and the need for wasteful bandwidth division or dynamic interference mitigation techniques.

Innovation Solution

The system employs interference isolation through distinct frequency allocation for uplink and downlink communications between satellite and terrestrial components, allowing the same frequencies to be used simultaneously without coordination, utilizing active beam-steering and interference cancellation to minimize self-interference, and optimizing frequency reuse within allocated bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If frequency spectrum is shared between satellite and terrestrial systems, then bandwidth utilization is improved, but interference between components increases

Engineering Contradiction:
Improvebandwidth utilizationVSAvoidinterference
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The system segments the frequency spectrum into distinct uplink and downlink bands. Satellite uplink frequencies are separated from terrestrial uplink frequencies, and satellite downlink frequencies are separated from terrestrial downlink frequencies. This segmentation allows both systems to operate simultaneously in the same spectrum without mutual interference, resolving the contradiction between bandwidth utilization and interference.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If frequency division is used to mitigate interference, then interference is reduced, but bandwidth efficiency deteriorates

Engineering Contradiction:
ImproveinterferenceVSAvoidbandwidth efficiency
Core Design Contradiction:
Object-generated harmful factorsVSQuantity of substance

Solution Approach 1:

The system moves from traditional frequency division (one-dimensional separation) to a two-dimensional frequency allocation scheme where uplink and downlink are independently managed. By establishing distinct frequency relationships for uplink and downlink directions, the system achieves interference mitigation while maintaining high bandwidth efficiency, as each direction can fully utilize its allocated spectrum without wasting frequencies.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Object-generated harmful factors

If dynamic interference mitigation is implemented, then interference management is improved, but system complexity increases

Engineering Contradiction:
Improveinterference managementVSAvoidsystem complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The system implements preliminary frequency allocation where uplink and downlink frequencies are pre-assigned to satellite and terrestrial components according to the invention's specified frequency relationships. This preliminary arrangement eliminates the need for complex real-time dynamic interference mitigation, as interference is prevented by design rather than through ongoing complex control mechanisms, thereby reducing system complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3114777B1Combined satellite and terrestrial communication system for terminals located on a vehicle such as an aircraft using a common set of frequencies.
Publication Date: 2020.01.22 INMARSAT GLOBAL
  • EP3114777B1 patent drawingFigure 1
  • EP3114777B1 patent drawingFigure 2
  • EP3114777B1 patent drawingFigure 3

AI summary

A combined satellite and terrestrial communication system may include at least one satellite earth station, for communication via a satellite with a plurality of terminals using one or more satellite links; a plurality of terrestrial stations, for communication with the plurality of terminals using one or more terrestrial links; wherein the satellite links overlap or coincide in frequency with the terrestrial links; and each of the terminals includes means for inhibiting interference between the satellite links and the terrestrial links.