Underwater communications system with adaptable carrier frequency
First Claim
1. An underwater communications system comprising:
- a transmitter which transmits electromagnetic and/or magnetic signals to a remote receiversaid transmitter comprising a data input, and a modulator for modulating the input data onto a carrier signal,at least one of said transmitter and said remote receiver being underwaterwherein said transmitter and said receiver are operable to communicate within a near field of said electromagnetic and/or magnetic signals, said near field of said electromagnetic and/or magnetic signals corresponding to the region around said transmitter where at least one of inverse distance squared (1/r2) and inverse distance cubed (1/r3) field components of said electromagnetic and/or magnetic signals is greater than an inverse distance (1/r) field component thereofand wherein said underwater communications system is operable to vary a frequency of said carrier signal based on range of operation.
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Accused Products
Abstract
An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.
84 Citations
27 Claims
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1. An underwater communications system comprising:
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a transmitter which transmits electromagnetic and/or magnetic signals to a remote receiver said transmitter comprising a data input, and a modulator for modulating the input data onto a carrier signal, at least one of said transmitter and said remote receiver being underwater wherein said transmitter and said receiver are operable to communicate within a near field of said electromagnetic and/or magnetic signals, said near field of said electromagnetic and/or magnetic signals corresponding to the region around said transmitter where at least one of inverse distance squared (1/r2) and inverse distance cubed (1/r3) field components of said electromagnetic and/or magnetic signals is greater than an inverse distance (1/r) field component thereof and wherein said underwater communications system is operable to vary a frequency of said carrier signal based on range of operation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification