Subscriber unit for beam acquisition in a satellite communication system and method therefor
First Claim
1. In a subscriber unit, a method for selecting an optimum communications beam from a plurality of communications beams transmitted from a plurality of communications nodes, comprising the steps of:
- measuring a propagation delay of said plurality of communications beams;
measuring a Doppler frequency shift of said plurality of communications beams;
comparing said propagation delay and said Doppler frequency shift of said plurality of communications beams; and
selecting said optimum communications beam based on said comparing step.
3 Assignments
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Accused Products
Abstract
In a communications system, an earth-based subscriber unit (40, FIG. 1) receives at least one communications beam (50, 60, FIG. 1) transmitted from one or more moving satellite communications nodes (10, 20). The earthbased subscriber unit evaluates which communications beam should be selected based on the power received (FIG. 2, 210), Doppler frequency shift (270), link quality, (290), interference level (300), and satellite and network specific parameters (310). By considering these factors, the earth-based subscriber unit selects the communications beam (50, 60) that will provide the optimum service and reduce the likelihood that an inter-satellite hand over of the call will be required while the call is in progress.
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Citations
6 Claims
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1. In a subscriber unit, a method for selecting an optimum communications beam from a plurality of communications beams transmitted from a plurality of communications nodes, comprising the steps of:
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measuring a propagation delay of said plurality of communications beams;
measuring a Doppler frequency shift of said plurality of communications beams;
comparing said propagation delay and said Doppler frequency shift of said plurality of communications beams; and
selecting said optimum communications beam based on said comparing step. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification