GEO Relay Satellite Optical Multiple-Access System
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Solution Overview
Problem
Current satellite communication systems, particularly those in geostationary Earth orbit (GEO), face limitations in supporting high-data-rate communications for multiple users due to their inflexible pre-allocation methods and inability to handle high data rates for modern, high-data-volume users, especially when compared to optical communication systems.
Innovation Solution
The implementation of an optical multiple-access (OMA) system using a GEO relay satellite equipped with a focal plane array (FPA) and bandpass filters, allowing for simultaneous detection and transmission of high-data-rate signals from multiple low-Earth orbit (LEO) satellites, enabling on-demand access and supporting hundreds of concurrent users with high-rate data delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional RF relay systems use pre-allocation methods, then system stability is maintained, but adaptability and flexibility are reduced
Solution Approach 1:
The patent implements dynamic resource allocation where the RF relay system continuously monitors channel conditions and user demands, adjusting power allocation and routing decisions in real-time based on current system state, transforming the static pre-allocation approach into a dynamic adaptive system
Solution Approach 2:
The system employs feedback mechanisms where channel quality indicators, buffer status, and user demand information are continuously reported to the relay satellite, which then adjusts its forwarding and power allocation decisions based on this feedback to maintain both flexibility and stability
2Productivity
If RF relay systems increase data rate capacity, then high-data-volume user support improves, but power consumption and interference increase
Solution Approach 1:
The patent dynamically changes transmission parameters including power level, modulation scheme, and coding rate based on channel conditions and user requirements, allowing the system to achieve high data rates when needed while reducing power consumption during normal operation
Solution Approach 2:
The system allocates high power and advanced modulation only to the subset of users and channels that require high data rates, while using lower power and simpler schemes for other users, avoiding unnecessary power consumption across the entire system
3Quantity of substance
If RF relay systems increase the number of supported users, then service coverage improves, but power per user and data rate decrease
Solution Approach 1:
The patent applies different power levels, modulation schemes, and resource allocation strategies to different users and channels based on their specific requirements, channel conditions, and QoS needs, allowing high data rates for priority users while supporting more users overall with appropriate resource distribution
Solution Approach 2:
The system segments users into different service classes and channels, allocating resources differently to each segment, allowing simultaneous support of high-rate users and low-rate users without compromising the data rate of critical users
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
The OMA system provides flexible, high-data-rate communication capabilities, supporting continuous and on-demand access for numerous users, overcoming the limitations of conventional radio frequency relay systems by utilizing narrow optical beams for efficient power delivery and interference reduction, thus enhancing satellite communication efficiency.
Implementation Method 1
a bandpass filter in optical communication with the first telescope and/or the FPA... The FPA detect the inbound free-space optical signal, which is filtered by the bandpass filter to transmit light at the first wavelength and reject light at other wavelengths
Implementation Method 2
a focal plane array (FPA) disposed in a back focal plane of the first telescope... The FPA detect the inbound free-space optical signal
Data Source
AI summary
A wide-field telescope and focal plane array (FPA) that look at Earth and satellites in low- and medium-Earth orbit (LEO and MEO) from a satellite in higher orbit, such as geostationary Earth orbit (GEO), can serve as a node in an on-demand, optical multiple access (OMA) communications network. The FPA receives asynchronous low-rate signals from LEO and MEO satellites and ground stations at a signal rate determined in part by the FPA frame rate (e.g., kHz to MHz). A controller tracks the low-rate signals across the FPA as the signal sources orbit Earth. The node also includes one or more transmitters that relay the received information to other nodes via wavelength-division multiplexed (WDM) free-space optical signals. These other signals may include low-rate telemetry communications, burst transmissions, and continuous data relay links.