Satellite Terrestrial Frequency Sharing via Gain and Power Control

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Solution Overview

Problem

Satellite radioterminal communications systems face challenges in efficiently utilizing frequency spectrum, particularly in densely populated areas where satellite signals are blocked, and the existing spectrum allocations do not support wideband technologies due to fragmented frequency bands.

Innovation Solution

Allowing two satellite radioterminal communications systems to share the same frequency in geographically overlapping footprints by adjusting the receive antenna gain and Effective Isotropic Radiated Power (EIRP) of ancillary terrestrial components to minimize interference and maintain Quality of Service (QoS).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If satellite signals are used in densely populated areas, then satellite communications can be provided, but the signals are blocked by high-rise structures and do not penetrate into buildings

Engineering Contradiction:

Improvesatellite signal availabilityVSAvoidsignal blockage by structures

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the coverage area into satellite footprint regions and terrestrial network regions, allowing each to operate independently in areas where they are most effective. The terrestrial network segments fill the coverage gaps in densely populated areas where satellite signals are blocked.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an interference reduction mechanism as an intermediary between satellite and terrestrial systems. This intermediary manages the interaction between the two systems, reducing harmful interference while enabling both to operate in overlapping regions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If terrestrial networks reuse satellite frequency bands, then system capacity is increased, but interference between satellite and terrestrial systems occurs

Engineering Contradiction:

Improvesystem capacityVSAvoidinterference between systems

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful interference into a beneficial arrangement by carefully coordinating the operation of satellite and terrestrial systems. The interference is managed and reduced to acceptable levels, allowing both systems to operate simultaneously and increase overall capacity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes key operating parameters including antenna gain, EIRP (Effective Isotropic Radiated Power), and frequency allocation to optimize the coexistence of satellite and terrestrial systems. These parameter adjustments reduce interference while maintaining system capacity.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If existing satellite spectrum allocations are used, then current systems can operate, but the bands are fragmented and do not support wideband technologies

Engineering Contradiction:

Improvesupport for wideband technologiesVSAvoidcontinuity of frequency bands

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges fragmented satellite frequency bands into larger continuous allocations by coordinating with terrestrial network frequency usage. This combining of previously separate allocations enables wideband technologies like WCDMA to operate effectively.

Inventive Principle:

Principle #5Merging (Combining)

4Productivity

If two satellite systems share the same frequency in overlapping footprints, then frequency utilization is improved, but interference between the systems increases

Engineering Contradiction:

Improvefrequency utilizationVSAvoidinter-system interference

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies different operational characteristics to different geographic regions within the footprint. In some areas, one satellite system operates with higher power while the other uses lower power, creating local quality variations that reduce overall interference while improving frequency utilization.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7925209B2Systems and methods for inter-system sharing of satellite communications frequencies within a common footprint

Publication Date: 2011.04.12 ATC TECHNOLOGIES LLC

AI summary

Two satellite communications systems can use the same frequency or frequencies in geographically overlapping footprints, without creating undue interference in a given system that is caused by the same frequency signal(s) that is/are used by the other system. In particular, an aggregate Effective Isotropic Radiated Power (EIRP) of the radioterminals and/or ancillary terrestrial components of a second satellite communications system in the common footprint is sufficiently low, and/or the receive antenna gain of a first satellite communications system is sufficiently low compared to the receive antenna gain of the second satellite communications system, so as to increase an aggregate receiver noise that is seen by the first satellite system receivers by an amount that does not substantially change a Quality of Service (QoS) of the first satellite communications system.