Bi-directional transponder apparatus and method of operation
First Claim
1. A method for providing a bi-directional, radio frequency (RF) communications link between a mobile platform and a communications station using a single, space-based transponder, comprising:
- segmenting a total bandwidth of said transponder into first and second portions;
setting a power output of said transponder at a predetermined power output level that is below saturation of said power output of said transponder;
using said transponder to transmit RF signals received from said communications station to said mobile platform at said predetermined power output level over said first bandwidth portion of said transponder; and
using said transponder to transmit RF signals received from said mobile platform to said communications station at said predetermined power output level over said second bandwidth portion of said transponder.
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Accused Products
Abstract
A bi-directional radio frequency transponder apparatus and method of operation therefor. The single, bi-directional transponder has its bandwidth segmented into two distinct, non-overlapping frequency portions, one for handling forward link signals from a base station to a mobile platform and the other for handling return link signals from the mobile platform to the base station. The output of the transponder is reduced by at least about 1 dB below saturation, and more preferably by about 1 dB-3 dB below saturation. This prevents suppression of the relative small return link signals in the presence of the much larger forward link signals. The overall cost of the transponder system is reduced by half over that of a conventional dual transponder system without significantly degrading forward link or return link capacity.
58 Citations
30 Claims
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1. A method for providing a bi-directional, radio frequency (RF) communications link between a mobile platform and a communications station using a single, space-based transponder, comprising:
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segmenting a total bandwidth of said transponder into first and second portions;
setting a power output of said transponder at a predetermined power output level that is below saturation of said power output of said transponder;
using said transponder to transmit RF signals received from said communications station to said mobile platform at said predetermined power output level over said first bandwidth portion of said transponder; and
using said transponder to transmit RF signals received from said mobile platform to said communications station at said predetermined power output level over said second bandwidth portion of said transponder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for forming a bi-directional, radio frequency (RF) communications link between a mobile platform and a base station using a single, satellite-based transponder, comprising:
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segmenting a total bandwidth of said transponder into first and second portions;
setting a power output of said transponder at a power output level that is at least about 1 dB below saturation of said power output of said transponder;
using said first bandwidth portion to form a forward transmission link over which RF signals are transmitted from said base station to said mobile platform; and
using said second bandwidth portion to form a return transmission link over which RF signals are transmitted from said mobile platform to said base station. - View Dependent Claims (10, 11, 12, 13)
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14. A method for operating a single radio frequency (RF) transponder to facilitate a bi-directional communications link between a first RF communications station and a second RF communications station, comprising:
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segmenting an overall bandwidth of said transponder into first and second portions;
setting a power output of said transponder at a predetermined power output level that is below saturation of said power output of said transponder;
using said first bandwidth portion to form a forward communications link for RF signals received by said transponder from said first communications station and transmitted by said transponder to said second communications station; and
using said second bandwidth portion to form a return communications link for RF signals received from said second communications station by said transponder and transmitted by said transponder to said first communications station. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. A space based, radio frequency (RF) transponder for facilitating a bi-directional communications link between a communications station and a mobile platform operating within a predefined geographic coverage region in which said communications station is located, said transponder comprising:
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an overall bandwidth partitioned into first and second portions, said first portion forming a forward link transmission path from said communications station to said mobile platform, and said second portion forming a return link transmission path from said mobile platform to said communications station; and
a power output of said transponder being set at a predetermined power output level that is below saturation of said power output of said transponder. - View Dependent Claims (22, 23)
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24. A communications system, comprising:
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a radio frequency (RF) communications station located within a predefined geographic coverage region;
a mobile platform carrying a RF transceiver, said mobile platform operating within said geographic coverage region;
a space-based RF transponder orbiting the earth above said predefined geographic coverage region;
said space-based transponder including;
an overall bandwidth that is segmented into first and second, non-overlapping portions; and
a power output that is set at a predetermined level below saturation;
said first bandwidth portion being used to form a forward transmission link between said RF communications station and said mobile platform; and
said second bandwidth portion being used to form a return transmission link between said mobile platform and said RF communications station. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification