Underwater location and communication system
First Claim
1. A communication and position determining device for use in an underwater location and communication system, comprising:
- a control unit for selecting a sequence of one or more data words containing information to be communicated to a second communication and position determining device wherein each data word includes a plurality of data bits,a signal generator responsive to each data word for generating a plurality of concurrent signals whereineach signal represents a data bit of a data word and occupies a different frequency band,a directional receiving hydrophone assembly for receiving each data word transmitted by another communication and position determining device and generating omni, sine and cosine channel signals respectively representing the data word signals and the sine and cosine directional components of the data word signals received by the hydrophone assembly, anda signal processing unit connected from the directional receiving hydrophone and responsive to a first response signal of a first response data word transmitted by another communication and position determining device in response to the interrogation data word fordetecting the time of reception the first response signal, anddetermining the bearing of reception of the first response signal wherein the bearing of reception of the first response signal represents the bearing of the other communication and position determining device with respect to the communication and position determining device, anddetermining the range between the communication and position determining device and the other communication and position determining device as represented by the round trip propagation interval between the communication and position determining units as represented by the interval between the transmission of the interrogation signal of the interrogation data word and the reception of the first response signal of the first response data word,wherein each signal is selected from one of a pair of upswept and downswept frequency modulated signals that can be discriminated from one another and wherein one waveform of the pair represents a logic 1 and the other waveform represents a logic 0, and whereinthe frequency bands are separated from one another by guard bands having widths sufficient to prevent intersymbol interference between the signals representing the data bits of a data word, andsuccessive data words are separated sequentially in time by intervals having a duration sufficient to prevent intersymbol interference between the signals of successive data words, andan acoustic transducer connected from the signal generator for concurrently transmitting the plurality of signals representing a data word.
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Accused Products
Abstract
A communication and position determining device for use in an underwater communication and position determining system wherein the device transmits a sequence of one or more data words, wherein each data word includes a plurality of data bits transmitted in parallel as a corresponding number of concurrently transmitted signals, each of which occupies a different frequency band. The signals have waveforms selected from a pair of fade resistant waveforms that can be discriminated from one another, to represent binary data and the frequency bands are separated from one another by guard bands having widths sufficient to prevent intersymbol interference between the signals representing the data bits of a data word due, for example, to doppler and phase/frequency shifting, and successive data words are separated sequentially in time by intervals having a duration sufficient to prevent intersymbol interference between the signals of successive data words due to multipath reverberation. A single one of the signals of a data word is used for position determination wherein two devices each determine the bearing to one another from the bearing of the signals received from the other and a round trip propagation time determined from the time delay in transmitting an interrogation data word, a first response data word and a second response data word. Various alternative implementations of the invention are described.
136 Citations
27 Claims
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1. A communication and position determining device for use in an underwater location and communication system, comprising:
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a control unit for selecting a sequence of one or more data words containing information to be communicated to a second communication and position determining device wherein each data word includes a plurality of data bits, a signal generator responsive to each data word for generating a plurality of concurrent signals wherein each signal represents a data bit of a data word and occupies a different frequency band, a directional receiving hydrophone assembly for receiving each data word transmitted by another communication and position determining device and generating omni, sine and cosine channel signals respectively representing the data word signals and the sine and cosine directional components of the data word signals received by the hydrophone assembly, and a signal processing unit connected from the directional receiving hydrophone and responsive to a first response signal of a first response data word transmitted by another communication and position determining device in response to the interrogation data word for detecting the time of reception the first response signal, and determining the bearing of reception of the first response signal wherein the bearing of reception of the first response signal represents the bearing of the other communication and position determining device with respect to the communication and position determining device, and determining the range between the communication and position determining device and the other communication and position determining device as represented by the round trip propagation interval between the communication and position determining units as represented by the interval between the transmission of the interrogation signal of the interrogation data word and the reception of the first response signal of the first response data word, wherein each signal is selected from one of a pair of upswept and downswept frequency modulated signals that can be discriminated from one another and wherein one waveform of the pair represents a logic 1 and the other waveform represents a logic 0, and wherein the frequency bands are separated from one another by guard bands having widths sufficient to prevent intersymbol interference between the signals representing the data bits of a data word, and successive data words are separated sequentially in time by intervals having a duration sufficient to prevent intersymbol interference between the signals of successive data words, and an acoustic transducer connected from the signal generator for concurrently transmitting the plurality of signals representing a data word. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 21)
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11. The communication and position determining device for use in an underwater location and communication system, comprising:
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a control unit for selecting a sequence of one or more data words containing information to be communicated to a second communication and position determining device wherein each data word includes a plurality of data bits, a signal generator responsive to each data word for generating a plurality of concurrent signals wherein each signal represents a data bit of a data word and occupies a different frequency band, wherein the signals have waveforms selected from a pair of fade resistant waveforms that can be discriminated from one another and wherein one waveform of the pair represents a logic 1 and the other waveform represents a logic 0, and the frequency bands are separated from one another by guard bands having widths sufficient to prevent intersymbol interference between the signals representing the data bits of a data word, and successive data words are separated sequentially in time by intervals having a duration sufficient to prevent intersymbol interference between the signals of successive data words, and an acoustic transducer connected from the signal generator for concurrently transmitting the plurality of signals representing a data word, the control unit responsive to a user command to determine the location of the communication and position determining unit with respect to another communication and position determining unit for generating an interrogation data word, the signal generator responsive to the interrogation data word for generating the signals of the interrogation data word wherein at least one signal of the interrogation data word is an interrogation signal, the acoustic transducer is responsive to the signal generator for transmitting the signals of the interrogation data word, including the at least one interrogation signal, a directional receiving hydrophone assembly for receiving a data word transmitted by another communication and position determining device and generating omni, sine and cosine channel signals respectively representing the data word signals and the sine and cosine directional components of the data word signals received by the hydrophone assembly, and a signal processing unit connected from the directional receiving hydrophone and responsive to a first response signal of a first response data word transmitted by another communication and position determining device in response to the interrogation data word for detecting the time of reception the first response signal, and determining the bearing of reception of the first response signal wherein the bearing of reception of the first response signal represents the bearing of the other communication and position determining device with respect to the communication and position determining device, and determining the range between the communication and position determining device and the other communication and position determining device as represented by a round trip propagation interval between the communication and position determining units as represented by the interval between the transmission of the interrogation signal of the interrogation data word and the reception of the first response signal of the first response data word. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 22, 23, 26, 27)
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24. The communication and position determining device for use in an underwater location and communication system, comprising:
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a control unit for selecting a sequence of one or more data words containing information to be communicated to a second communication and position determining device wherein each data word includes a plurality of data bits, a signal generator responsive to each data word for generating a plurality of concurrent signals wherein each signal represents a data bit of a data word and occupies a different frequency band, wherein the signals have waveforms selected from a pair of fade resistant waveforms that can be discriminated from one another and wherein one waveform of the pair represents a logic 1 and the other waveform represents a logic 0, and wherein the frequency bands are separated from one another by guard bands having widths sufficient to prevent intersymbol interference between the signals representing the data bits of a data word, and successive data words are separated sequentially in time by intervals having a duration sufficient to prevent intersymbol interference between the signals of successive data words, and an acoustic transducer connected from the signal generator for concurrently transmitting the plurality of signals representing a data word, and a receiving transducer assembly, including a multi-segment, three dimensional spherical directional receiving transducer for receiving a data word transmitted by another communication and position determining device, and for each of a plurality of angles of rotation in three dimensions of a receiving pattern of the transducer, a combining network connected from selected segments of the spherical receiving transducer for generating segment channel signals respectively representing the data word signals and the directional components of the data word signals received by the transducer at a corresponding angle of rotation of the receiving pattern, and a signal processing unit connected from the combining networks for performing a pattern matching operation comparing the signals of each segment channel with corresponding patterns for a set of pre-selected direction vectors and providing as an output a selected one of the set of pre-selected direction vectors which best corresponds to the received vector signals wherein the selected one of the set of pre-selected direction vectors represents in angle of reception in three dimensions of the data word received from the other communication and position determining unit. - View Dependent Claims (25)
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Specification