US 6,130,859 AGranted

Method and apparatus for carrying out high data rate and voice underwater communication

AssigneeDivecom Ltd.

InventorsMenashe Sonnenschein, Dov Wulich, Elazar Sonnenschein

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Abstract

An underwater apparatus for transmitting and receiving high rate data and voice communication including a transmitter, a receiver, and a Doppler frequency shift compensator. The transmitter includes a data source comprising digital data to be transmitted by the apparatus through the water, a serial-to-parallel data processor for splitting the serial digital data into n parallel data channels, a n-channel modulator for receiving the n parallel data channels and for modulating those channels with n pairs of ultrasonic carriers to produce a modulated signal. The transmitter also includes a hydrophone for receiving and transmitting the modulated signal. The receiver includes a hydrophone for receiving a modulated signal. The receiver also includes RF circuitry for amplifying and shaping the received modulated signal, a serial-to-parallel data processor for splitting the amplified and shaped data into n parallel channels, a n-channel demodulator for demodulating the shaped signal and for outputting n channels of digital data, and a parallel-to-serial data processor for receiving n parallel channels of data from the demodulator and for combining those channels into serial data. The Doppler compensator measures the frequency of at least one of two unmodulated signals transmitted as part of the modulated signal and compares the measured frequency with a predetermined frequency. Operation of the demodulator is adjusted to compensate for any deviation between the measured and predetermined frequency.

Claims31

Dependent claims

An underwater modulator-demodulator (modem) apparatus for transmitting and receiving data at a high rate through water, said modem comprising:

a. A transmitting section comprising:
data source means, comprising digital data to be transmitted through water;
serial-to-parallel data processing means, for splitting a serial data into n parallel channels;
n-channel modulator means, for receiving data from said n parallel channels and for modulating the same with n pairs of ultrasonic carriers, thereby producing a modulated signal;
and
hydrophone means, for receiving said modulated signal from said n channel modulator means, and for transmitting same into water;
b. A receiving section comprising:
hydrophone means, for receiving a modulated signal from the water, and for conveying the same into an RF circuit;
RF circuitry, for amplifying and shaping the received modulated signal, and for converting the received modulated signal to serial digital data and for conveying the same into serial-to-parallel means;
serial-to-parallel means, for receiving said serial digital data from the RF circuit, and for splitting the same into n parallel channels;
n-channel demodulator means, for demodulating said serial digital data conveyed to the demodulator from said RF circuit, and for outputting n parallel channels of digital data;
and
parallel-to-serial means for receiving n parallel channels of outputted data from the demodulator means, and for converting the data into serial data;
and
c. means for compensating for the Doppler effect on a transmitted signal propagating through water comprising, in the modulator means of the transmitting section, means for transmitting two unmodulated carriers and, in the receiving section, a frequency adjusting device for measuring the frequency of at least one of said two unmodulated carriers and for comparing said measured frequency with a predetermined frequency and for adjusting the n-channel demodulator means for any deviation between said measured frequency and said predetermined frequency.

12 more elements

An underwater communication apparatus for transmitting and receiving data comprising:

a transmitter comprising:
a digital data source;
a serial-to-parallel converter for receiving serial digital data from said digital data source and for converting said received serial digital data to more than two parallel data channels;
a multi-channel modulator for receiving more than two parallel data channels from said serial-to-parallel converter and for modulating each of said more than two parallel data channels with an ultrasonic carrier to produce a modulated signal;
and
a transmitting hydrophone for receiving said modulated signal and for transmitting said modulated signal in water;
a receiver comprising:
a receiving hydrophone for receiving a modulated signal;
a RF circuit connected to said hydrophone for receiving therefrom said received modulated signal, said RF circuit amplifying and shaping said received modulated signal and converting said received modulated signal to serial data;
a serial-to-parallel converter for receiving said serial data from said RF circuit and for converting said serial data to more than two parallel data channels;
a multi-channel demodulator for receiving from said serial-to-parallel converter said more than two parallel data channels and for demodulating each of said more than two parallel data channels and for outputting more than two parallel data channels;
and
a parallel-to-serial converter for receiving from said multi-channel demodulator said more than two parallel data channels and for converting said more than two parallel data channels into serial data;
and
Doppler effect compensator comprising, in the multi-channel modulator, a transmitter for transmitting two unmodulated carriers and, in the receiver, a frequency adjusting device for measuring the frequency of at least one of said two unmodulated carriers and for comparing said measured frequency with a predetermined frequency and for adjusting said multi-channel demodulator for any deviation between said measured frequency and said predetermined frequency.

12 more elements

Dependencies are inferred from the claim text.