Satellite Beam Switching Timing Control for SNR Maintenance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-geostationary satellite systems face challenges in maintaining signal-to-noise ratio (SNR) due to beam pointing inaccuracies, leading to gaps in coverage and unequal signal strengths when user terminals switch between satellite beams, with existing solutions either resulting in excessive traffic, high hardware costs, or accepting poorer quality of service.
Innovation Solution
A timing-based approach is used to determine beam switchover times, correlating angular offsets and timing discrepancies to adjust switch times or correct satellite attitude, ensuring equal signal strengths and maintaining SNR by obtaining beam pointing information from user terminals and using it to adjust switch times or satellite pointing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If user terminals switch beams based on comparing received power, then beam switching can be performed, but excessive overhead traffic is generated
Solution Approach 1:
The system pre-calculates beam switchover times based on satellite ephemeris data and terminal position, storing them in a look-up table. This preliminary action eliminates the need for real-time power comparison and signaling during beam switching, thus reducing overhead traffic while maintaining switching functionality
Solution Approach 2:
The system measures actual received power at the terminal and compares it with expected power levels. The discrepancy is fed back to adjust beam switchover times, creating a closed-loop system that maintains constant SNR without requiring excessive overhead traffic for coordination
2Reliability
If tight tolerances are imposed on beam pointing, then SNR can be maintained, but hardware cost increases
Solution Approach 1:
Instead of relying on tight physical tolerances in beam pointing hardware, the system changes the operational parameter by dynamically adjusting beam switchover times based on measured power discrepancies. This software-based parameter adjustment achieves reliable SNR maintenance without requiring expensive tight-tolerance hardware
Solution Approach 2:
The invention replaces the mechanical approach of ensuring precise beam pointing through expensive hardware tolerances with a computational approach using timing adjustments. This substitution eliminates the need for high-precision mechanical alignment while maintaining system reliability
3Ease of manufacture
If beam pointing errors are accepted, then hardware costs are reduced, but quality of service deteriorates
Solution Approach 1:
The system continuously measures received power and uses this feedback to calculate timing adjustments that compensate for beam pointing errors. This feedback mechanism maintains quality of service despite relaxed hardware tolerances, allowing cost-effective manufacturing without sacrificing performance
Data Source
AI summary
A system and method for maintaining signal-to-noise ratio when a user terminal switches beams includes a user terminal that generates beam-pointing information. The beam-pointing information is used either to alter the time at which the user terminal switches communications from a first beam to a second beam transmitted from a satellite or to adjust the attitude of the satellite, thereby correcting any error in pointing angle of the beams transmitted from the satellite to the user terminal.