Robust Low-Frequency Spread-Spectrum Navigation System
2 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.
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Citations
64 Claims
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1-27. -27. (canceled)
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28. A method comprising:
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providing a plurality of radiolocation transmitters for a desired coverage area; locking the plurality of radiolocation transmitters to a common timing reference; and transmitting a radiolocation signal, using a hybrid spread spectrum waveform that combines a direct sequence modulation with a frequency hopping, a time hopping, or a time gating protocol, from each of the plurality of radiolocation transmitters. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A method comprising:
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providing a plurality of radiolocation transmitters for a desired coverage area; locking the plurality of radiolocation transmitters to a common timing reference; transmitting a radiolocation signal, using a spread-spectrum waveform, from each of the plurality of radiolocation transmitters; turning off or reducing an output power of a first radiolocation transmitter of the plurality of radiolocation transmitters during a first time period; resuming standard output power for the first radiolocation transmitter during a second time period; and turning off or reducing an output power of a second radiolocation transmitter of the plurality of radiolocation transmitters during the second time period. - View Dependent Claims (43, 44, 45, 46, 47)
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48. A method comprising:
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providing a plurality of radiolocation transmitters for a desired coverage area; locking the plurality of radiolocation transmitters to a common timing reference; and transmitting a ground wave radiolocation signal, using a spread-spectrum waveform, from each of the plurality of radiolocation transmitters. - View Dependent Claims (49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59)
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60. A method comprising:
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providing a plurality of radiolocation transmitters for a desired coverage area; locking the plurality of radiolocation transmitters to a common timing reference; and transmitting a radiolocation signal, using a frequency hopping protocol and a spread-spectrum waveform, from each of the plurality of radiolocation transmitters. - View Dependent Claims (61, 62, 63, 64)
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Specification