Acquisition guard time reduction using triangulation ranging

Abstract

Embodiments provide systems, devices, and methods for determining acquisition guard times and acquisition control parameters or distance metrics for terminals in a satellite communication network using triangulation and single terminal ranging. A terminal or multiple terminals from the network may be selected as ranging terminals; the terminals may include normal user terminals used for determining a satellite position or a satellite distance. Ranging terminals may first enter a network and synchronize to TDMA frame timing by adjusting the acquisition control parameters. An adjusted acquisition control parameter may also be called a transmit timing control parameter. A satellite position or a distance difference between a real-time and a nominal satellite position may be estimated from timing control parameters. Information about the satellite position and/or the distance difference in satellite position may then be used to reduce acquisition guard times for other terminals using various techniques to compute acquisition control parameters.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is a non-provisional claiming priority benefit of U.S. provisional patent application Ser. No. 61 / 180,697, filed on May 22, 2009 and entitled “Acquisition Guard Time Reduction Using Triangulation and Single Terminal Ranging,” the entire disclosure of which is herein incorporated by reference for all purposes. This application is related to U.S. patent application Ser. No. ______, filed concurrently with this application and entitled “Acquisition Guard Time Reduction Using Single Terminal Ranging,” incorporated by reference for all purposes.BACKGROUND[0002]The present invention is related to satellite communications in general and, more specifically, to determining acquisition guard times for very small aperture terminal (VSAT) networks utilizing a time-division multiple access (TDMA) technique. When a terminal enters a TDMA network, the terminal typically needs to synchronize its transmit timing to a TDMA network frame t...

AI Technical Summary

Benefits of technology

[0007]Embodiments of triangulation ranging may provide accurate satellite positions while reducing acquisition guard time, which may improve frame efficiency and acquisition time. Embodiments of triangulation ranging may also be effective for large orbit inclinations.

Problems solved by technology

While these techniques for determining acquisition guard time may be simple, they may result in a large acquisition guard time, in particular for a large orbit inclination.

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