Communications system
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.
1. A communications system comprising:
a data input;
a modulator, for modulating data onto a carrier signal;
a transmitter,
a remote receiver,
wherein the transmitter is provided with an antenna for transmitting modulated electromagnetic and/or magnetic signals to a remote receiver and at least one of the transmitter and/or remote receiver is placed in a fluid propagating medium; and
a digital data compressor for compressing data that is to be transmitted, wherein said the digital data compressor is configured to reduce occupied transmission bandwidth such as to increase the range of signal reception underwater.
2. The communications system of claim 1 wherein each said antenna is an electrically insulated, magnetic coupled antenna.
3. The communications system of claim 1 wherein each said antenna is an electric field coupled antenna.
4. The communications system of claim 1 further comprising a demodulator, for demodulating modulated signals received by the receiver.
5. The communication system of claim 1 further comprising a digital data de-compressor for decompressing the demodulated signals output from the demodulator.
6. The communications system of claim 1 wherein the said data input includes at least one of a text input; an audio input for capturing audio signals; an image input for capturing an image and a video input for capturing a video image.
7. The communications system of claim 1 wherein each said antenna includes at least one of loops and solenoids.
8. The communications system of claim 1 wherein each said antenna is surrounded with a material with a permittivity to match to that of the propagating medium.
9. The communications system of claim 1 wherein the propagating medium is substantially water.
10. The communications system of claim 1 wherein one or more intermediate transceivers are provided between the transmitter and the remote receiver to relay signals between said transmitter and said remote receiver.
11. The communications system of claim 10 wherein at least one of the said one or more intermediate transceivers and one of said transmitter or remote receiver are under water and are operable to pass a signal between one another through a water propagation path.
12. The communications system of claim 10 wherein at least one of the said plurality of intermediate transceivers and one of said transmitter or remote receiver are in air and are operable to pass a signal between one another through an air propagation path.
13. The communications system of claim 1 wherein the said transmitter and said remote receiver are each placed in a fluid propagating medium.
14. The communication system of claim 1 wherein the said transmitter is placed in a first fluid propagating medium and the said remote receiver is place in a second fluid propagating medium.
15. The communications system of claim 1 wherein at least part of the communications system is positioned in a fluid propagating medium.
16. The communications system of claim 1 wherein the propagating medium is a non-water fluid or gas.
17. The communications system of claim 1 wherein said transmitter and said receiver are operable to communicate within a near field of said electromagnetic and/or magnetic signals.
18. The communications system of system of claim 1 wherein said near field of said electromagnetic and/or magnetic signals corresponds to the region around said transmitter wherein at least one of inverse distance squared (1/r 2 ) and inverse distance cubed (1/r 3 ) field components of said electromagnetic and/or magnetic signals is greater than an inverse distance (1/r) field component thereof.
19. A communications system comprising:
a data input;
a modulator, for modulating data onto a carrier signal;
a transmitter, and
a remote receiver,
wherein the transmitter is provided with an antenna for transmitting modulated electromagnetic and/or magnetic signals to a remote receiver, at least one of the transmitter and/or remote receiver is placed in a fluid propagating medium and each of said transmitter and receiver is operable to communicate within a near field of said electromagnetic and/or magnetic signals, said near field corresponding to the region around the transmitter wherein at least one of inverse distance squared (1/r 2 ) and inverse distance cubed (1/r 3 ) field components of said electromagnetic and/or magnetic signals is greater than an inverse distance (1/r) field component thereof.