Multi-Satellite Gateway Polarization Signal Combining

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Solution Overview

Problem

Satellite communication systems face challenges in increasing power for communication links without significantly increasing costs, while also mitigating interference from nearby satellites, which affects signal strength and quality.

Innovation Solution

The system employs multiple satellites and a gateway with multiple antennas to receive and transmit polarized and orthogonally polarized signals, using orthogonal frequency-division multiplexing (OFDM) and interference cancellation techniques to enhance signal strength and power efficiency, allowing for increased return feeder link power with minimal additional power budget.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If satellite power is increased to improve communication link quality, then signal strength is improved, but system cost increases significantly

Engineering Contradiction:
Improvecommunication link powerVSAvoidsystem cost
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent combines signals from multiple satellites at the gateway using signal combining techniques. Multiple lower-power satellite links are merged to achieve the equivalent of a single high-power link, improving return feeder link power without proportionally increasing system cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the communication function across multiple satellites rather than relying on a single satellite. The gateway receives and processes signals from multiple satellites independently, then combines them to achieve higher effective power and improved link quality.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If subscriber terminals use wide beam antennas to easily point at target satellite, then ease of operation is improved, but interference from nearby satellites increases

Engineering Contradiction:
Improveantenna pointing easeVSAvoidinterference from nearby satellites
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful interference from nearby satellites into a beneficial signal by receiving and combining it at the gateway. The gateway collects signals from multiple satellites including those that would otherwise be interference, and combines them constructively to improve the overall signal strength.

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

Solution Approach 2:

The gateway acts as an intermediary between the subscriber terminal and multiple satellites. It receives signals from multiple satellites including potential interferers, processes and combines them, then delivers the combined signal to the subscriber terminal, effectively filtering and managing interference at the gateway level.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple satellites are used to increase bandwidth and signal strength, then communication quality is improved, but system complexity increases

Engineering Contradiction:
Improvecommunication qualityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The gateway is designed with multi-functionality to handle signals from multiple satellites simultaneously. It performs multiple functions including receiving signals from different satellites, separating polarized signals, combining signals, and managing interference, all within a single unified system that manages the complexity centrally.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Productivity

If orthogonal polarization is used to double bandwidth in the same geographic area, then productivity is improved, but signal separation and processing complexity increases

Engineering Contradiction:
Improvebandwidth capacityVSAvoidsignal processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies different polarization properties to different signal paths. The gateway uses polarized and orthogonally polarized antennas to receive signals from different satellites, exploiting the local polarization characteristics to separate and process signals independently, enabling doubled bandwidth capacity.

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 effectively doubles the return feeder link power with a small increase in overall power usage, improving signal strength and quality while maintaining cost efficiency, and compensates for interference from nearby satellites.

Implementation Method 1

The first antenna is configured to receive the polarized signals from the first and second satellites, and a second antenna is configured to receive the orthogonally polarized signals from the first and second satellites

Methodology Applied
Scientific EffectPolarisation: Polarisation

Data Source

PatentEP2055020B1Multi-satellite communication systems
Publication Date: 2017.04.12 VIASAT INC
  • EP2055020B1 patent drawingFigure 1A
  • EP2055020B1 patent drawingFigure 1B
  • EP2055020B1 patent drawingFigure 2

AI summary

Satellite communication systems and methods are disclosed. The communication system may include a gateway in communication with two satellites. The satellites are configured to receive polarized signals from a first plurality of users and orthogonally polarized signals from a second plurality of users. The signal may be an OFDM signal. The subscriber terminals may include an antenna pointed toward at least one of the satellites and configured to receive OFDM signals. The OFDM signal time is proportional to the longest transmission time difference of all subscriber terminals within the geographic area serviced by the satellites. Various other communication schemes are disclosed utilizing multiple satellites are also disclosed.