AU2019259866B2 - Method for adjusting a transmission parameter of a transmitter of an underwater communication device - Google Patents
Method for adjusting a transmission parameter of a transmitter of an underwater communication device Download PDFInfo
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- AU2019259866B2 AU2019259866B2 AU2019259866A AU2019259866A AU2019259866B2 AU 2019259866 B2 AU2019259866 B2 AU 2019259866B2 AU 2019259866 A AU2019259866 A AU 2019259866A AU 2019259866 A AU2019259866 A AU 2019259866A AU 2019259866 B2 AU2019259866 B2 AU 2019259866B2
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B11/00—Transmission systems employing ultrasonic, sonic or infrasonic waves
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C23/00—Non-electrical signal transmission systems, e.g. optical systems
- G08C23/02—Non-electrical signal transmission systems, e.g. optical systems using infrasonic, sonic or ultrasonic waves
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B13/00—Transmission systems characterised by the medium used for transmission, not provided for in groups H04B3/00 - H04B11/00
- H04B13/02—Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy
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- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
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Abstract
The invention relates to a novel method for operating a transmitter of an underwater communication device. The method is to be designed such that a transmitted message can be received correctly by another underwater communication device with a high degree of probability. In the novel method, at least one transmission parameter of a transmitter (1) of an underwater communication device is set as follows: - a transmission message is combined with a transmission test value in a computer (10), - the transmission message is modulated in a modulator (20), thereby obtaining a signal, - the signal is emitted using a transmission converter (24), - the emitted signal is modified by the transmission medium, - the modified signal is received by a receiving hydrophone (34), - the modified signal is demodulated in a demodulator (30), thereby obtaining a demodulated message, - a demodulated test value is ascertained from the demodulated message in the computer (10), said test value being compared with the transmission test value, and - if the demodulated test value does not match the transmission test value or if the demodulated message does not match the transmission message, the at least one transmission parameter is modified with respect to robustness, and the transmission message is emitted again with a modified transmission parameter or modified transmission parameters.
Description
190135P10WO 15.04.2019
Method for Setting Transmission Parameters of a Transmitter of an Underwater Com munication Device
Field of Invention The invention relates to a method for setting transmission parameters of a transmitter of an underwater communication device. The underwater communication device is an optional com munication node of an underwater network.
Background From US 5 018 114 A and US 2005/0088916 Al, methods for operating a transmitter of an underwater communication device are known. Both methods use a transmitter with a computer as well as a modulator, in such a way that the modulator influences a transmission amplifier, which is connected to a transmission converter. A message with a check value is compiled in the computer. In the modulator, the message is modulated while obtaining a time signal. Before transmitting, the message is sent back to the modulator electrically via a demodulator and evaluated. The signal is transmitted with the transmission converter in the event of correct evaluation. Either a transmission operation or a reception operation takes place. A toggle switch is used for this. When an underwater communications device is transmitting, it does not receive, and vice versa. The underwater communication device switches to the receive mode after a transmission, so it cannot receive and decode its own transmissions.
An underwater transmission method called "JANUS" is described in a textbook (authors: John Potter, Joao Alves, Dale Green, Giovanni Zappa, Kim McCoy and Ivor Nissen; published in September 2014, chapter title: "The JANUS underwater communications standard"; book title: "2014 Underwater Communications and Networking, UComms 2014"). In JANUS, transmis sion parameters are the frequency band and the transmission power, for example. JANUS defines a check value (CRC) that confirms the correctness of the message. As the first stage the correct decoding capability of a transmitted message can be derived from this.
Summary An embodiment of the invention provides a method for operating a transmitter of an underwater communication device in such a way that a transmitted message can be received correctly by another underwater communication device with a high probability.
190135P10WO 15.04.2019
The method is used to set at least one transmission parameter of a transmitter of an underwa ter communication device. The method follows the principle of controlling human speech. By hearing their own voice while speaking, a person can correct their pronunciation. In other words, one can change one's voice, depending on how one perceives one's voice, and mod ulate it in such a way that one is understood well by others. Speech is emitted through the mouth, and the emission is perceived in parallel through the ears or the skeleton and is per ceived as good or incomprehensible. It is instantly either spoken again with changed "trans mission parameters" or the "transmission parameters" are retained. The core point is the use of the change by the transmission medium and the simultaneous sending and receiving of one's own transmission. The transmission parameters are estimated without feedback from the receiver.
The invention also provides a method for setting at least one transmission parameter of a transmitter of an underwater communication device, wherein the method uses a transmitter with a computer and a modulator, in such a way that the modulator influences a transmission amplifier connected to a transmission converter and in such a way that the computer also has a demodulator connected to a receiving hydrophone via an intermediate reception amplifier, the method comprising: a) compiling, in the computer, a transmission message with a transmission check value, b) modulating, in the modulator, the transmission message while obtaining a signal, c) transmitting the signal with the transmission converter, d) modifying the transmitted signal by the transmission medium, e) receiving the modified signal by the receiving hydrophone, f) demodulating, in the demodulator, the modified signal while obtaining a demodulated message, g) determining a demodulated check value from the demodulated message in the com puter, and comparing the demodulated check value with the transmission check value, h) if the demodulated check value and the transmission check value match, performing a content check of the demodulated message with the transmission message, and retaining the at least one transmission parameter for further transmission tasks, or modifying the at least one transmission parameter with a view to optimizing the data rate and/or emission rate for the next transmission, and i) if the demodulated check value and the transmission check value or the demodulated message and the transmission message do not match, changing the at least one transmission
190135P10WO 15.04.2019
parameter with respect to robustness and retransmitting the transmission message with a changed transmission parameter or changed transmission parameters.
According to an advantageous embodiment of the invention, a transmission parameter is the transmission power. The energy resource for underwater communication equipment is valua ble, thus a transmission should only be as "loud" as necessary. If the transmission power is set to "quiet", the communication partner cannot decode correctly, if it is too "loud", overmod ulation occurs or many reflections arise and the sustainability decreases.
According to an advantageous embodiment of the invention, the at least one transmission parameter is a transmission frequency bandwidth with an upper frequency and a lower fre quency. Since the ambient noise is not distributed equally against frequency in the underwater region, there are frequency ranges that lend themselves to or exclude themselves from use, thus the upper frequency and the lower frequency must be optimized accordingly.
According to an advantageous embodiment of the invention, the receiving hydrophone is lo cated at a minimum distance from the transmission converter, wherein the minimum distance is the speed of sound divided by an upper frequency divided by 4, wherein the upper frequency refers to a transmission frequency bandwidth. An incoherent evaluation with a significant field distribution change is thus possible.
Briefly Description of the Drawings Exemplary embodiments of the invention are described in more detail below using the drawing and with the use of the JANUS transmission method by way of example. Here, fig. 1 shows a transmitter of an underwater communication device as a schematic diagram.
Detailed Description of Embodiments The exemplary embodiment relates to a method for setting at least one transmission parameter of an underwater communication device. The method has the following steps (a) to (j). Each step is explained and expanded:
a) The method uses, with reference to fig. 1, a transmitter 1 with a computer 10 with a modulator 20, in such a way that the modulator 20 influences a transmission amplifier 22, which is connected to a transmission converter 24, and in such a way that the computer 10 also has a demodulator 30, which is connected to a receiving hydrophone 34.
190135P10WO 15.04.2019
b) In the computer, a binary transmission message (the message to be transmitted) is compiled with a transmission check value (executed as a CRC for JANUS). For this exemplary embodiment, the message X=50 16 1 139 252 0 192 is selected and the check value 84 is determined for this purpose. Both are compiled into the binary transmission message, HEX 32 10 01 8B FC 00 CO 54, which then totals 64 bits.
c) In the modulator, this binary transmission message is modulated based on the JANUS definition while obtaining a signal. Since the JANUS method is used for this exemplary em bodiment, we call it a JANUS signal. For this purpose, the specification of the frequency band (lower frequency=4000 Hz, upper frequency=8000 Hz), the detection threshold of 0.6 and the transmission power of 160 dB is necessary. The latter specification corresponds to full control of the signal between amplitude values of -1 and 1.
d) The transmission converter 24 transmits the JANUS signal.
e) The transmitted JANUS signal is modified by the transmission medium.
f) All signals and thus also the modified JANUS signal are received by the receiving hy drophone 34 in the transmitter 1 and digitally converted. The modified JANUS signal includes the transmission message and reverberations (discrete echoes or continuous). This reverber ation is caused by reflections on the surface of the water, on the seabed, on fjord slopes or sheet pile walls and as a volume reverberation. The modified JANUS signal also includes the prevailing ambient noise at the location of the transmitter, as well as various other effects. The multi-path superpositioning can cause destructive interference, parts of the signal are erased, and a temporal spread of 50 ms due to the reverberation is assumed. This will now be as sumed. g) In the demodulator 30, the modified JANUS signal is converted back with the JANUS specification while obtaining a demodulated message.
h) A demodulated check value, which is compared with the transmission check value, is determined from the demodulated message in the computer 10. The following three cases can now occur here as an example.
190135P10WO 15.04.2019
- First case: The demodulated message is Y=50 16 1 139 252 0 192 84. From this, the demodulated check value is determined, in this case 84, and is compared with the received check value 84. - Second case: The demodulated message is Y=50 16 1 128 225 35 74 195. From this the demodulated check value is determined, in this case 195, and is compared with the transmission check value 195. - Third case: The demodulated message is Y=50 16 1 128 225 35 74 194. From this the demodulated check value is determined, in this case 195, and is compared with the received check value 194.
i) Now two checks are carried out. First check: By default, JANUS uses a CRC check value for syntax checking. It is checked whether the demodulated check value and the trans mission check value match. The above three cases lead to the following situation:
- In the first case: syntax correct. - In the second case: syntax correct. - In the third case: syntax not correct.
Second check: Since the transmitter has the knowledge of which message it has transmitted, a semantic check is also performed. This is a content check of the demodulated message with the transmission message.
- In the first case: semantics correct 4 message correct. - In the second case: semantics not correct + there is a mutation. - In the third case: message incorrect because CRC is already incorrect.
In the second case, a receiver would assume a syntactically correct message without the transmitter's knowledge since the demodulated check value and the transmission check value match. The mutation could cause damage in the further processing process (arranged target depth deeper than seabed, rendezvous position on land, ... ). It continues with step j) analo gously to the third case.
In the first case, the syntax (CRC correct) and the semantics (content comparison) are correct, and the message is not repeated. However, transmission parameters for further broadcast tasks can be modified or maintained with a view to optimizing the data rate and/or emission rate for the next broadcast.
190135P10WO 15.04.2019
j) However, if the demodulated check value and transmission check value or the demod ulated message and the transmission message do not match (second and third cases), the at least one transmission parameter is changed with respect to robustness and the message is retransmitted with the new setting. There is an iterative modulation.
The at least one transmission parameter is the transmission power. The amplitude values, which in the example are between -1 and 1 at 160 dB for the signal, can be halved multiple times. Each halving results in a decrease of 6 dB. For example, if it is determined that the demodulated check value and the transmission check value or the demodulated message and the transmission message do not match (for example, because there is an overmodulation and strong reflections), the transmission power should be reduced by one level (for example, 6 dB) and the message retransmitted. The result is smaller echo inputs and less interference. A re mote communication receiver would also benefit from this approach. With regard to setting the transmission parameter of the transmission power, the temporal spread (echo time) in the changed signal could additionally be measured and taken into account.
The at least one transmission parameter is a frequency bandwidth with an upper frequency (fmax) and a lower frequency (fmin). In JANUS, the carrier frequency (fmax+fmin)/2 is coupled with the length of the symbols by means of the relationship 26/bandwidth, as well as carrier frequency/3=bandwidth. If the transmitter now determines that it cannot decode its own mes sage or that the demodulated check value and the transmission check value or the demodu lated message and the transmission message do not match, it has the option to use a different frequency band and move the frequency band limits fmin and fmax upwards, for example. Since the higher frequency portions of an environmental noise are also absorbed more than lower ones, the shift to higher frequencies makes sense if the range losses can be accepted. A new transmission in the higher frequency band may lead to an improvement in the control circuit. With regard to setting the frequency bandwidth transmission parameter with an upper frequency and a lowerfrequency, an inter-symbol interference (ISI) in the modified signal could be detected and taken into account in order to generate and transmit shorter or longer signals.
The receiving hydrophone 34 is located at a minimum distance from the transmission converter 24, wherein the minimum distance is the speed of sound divided by an upper frequency divided by 4, wherein the upper frequency relates to a transmission frequency bandwidth. A minimum distance is preferred, wherein the minimum distance is the speed of sound divided by the upper
190135P10WO 15.04.2019
frequency multiplied by 3 to 5, preferably by 4, to allow a good incoherent evaluation with a significant field distribution change.
It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.
In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
190135P10WO 15.04.2019
Reference character list
1 Transmitter 10 Computer
20 Modulator 22 Transmission amplifier 24 Transmission converter
30 Demodulator 32 Reception amplifier 34 Reception hydrophone
Claims (5)
1. A method for setting at least one transmission parameter of a transmitter of an under water communication device, wherein the method uses a transmitter with a computer and a modulator, in such a way that the modulator influences a transmission amplifier connected to a transmission converter and in such a way that the computer also has a demodulator con nected to a receiving hydrophone via an intermediate reception amplifier, the method compris ing: a) compiling, in the computer, a transmission message with a transmission check value, b) modulating, in the modulator, the transmission message while obtaining a signal, c) transmitting the signal with the transmission converter, d) modifying the transmitted signal by the transmission medium, e) receiving the modified signal by the receiving hydrophone, f) demodulating, in the demodulator, the modified signal while obtaining a demodulated message, g) determining a demodulated check value from the demodulated message in the com puter, and comparing the demodulated check value with the transmission check value, h) if the demodulated check value and the transmission check value match, performing a content check of the demodulated message with the transmission message, and retaining the at least one transmission parameter for further transmission tasks, or modifying the at least one transmission parameter with a view to optimizing the data rate and/or emission rate for the next transmission, and i) if the demodulated check value and the transmission check value or the demodulated message and the transmission message do not match, changing the at least one transmission parameter with respect to robustness and retransmitting the transmission message with a changed transmission parameter or changed transmission parameters.
2. The method according to claim 1, wherein the at least one transmission parameter is a transmission power.
3. The method according to claim 1 or 2, wherein the at least one transmission parameter is a transmission frequency bandwidth with an upper frequency and a lower frequency.
4. The method according to claim 3, wherein the receiving hydrophone is located at a minimum distance from the transmission converter, wherein the minimum distance is the
190135P10WO 15.04.2019
speed of sound divided by the upper frequency divided by 4, wherein the upper frequency refers to the transmission frequency bandwidth.
5. The method according to claim 1 or 2, wherein the receiving hydrophone is located at a minimum distance from the transmission converter, wherein the minimum distance is the speed of sound divided by an upperfrequency divided by 4, wherein the upperfrequency refers to a transmission frequency bandwidth.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102018003299.0A DE102018003299B3 (en) | 2018-04-24 | 2018-04-24 | Method for setting transmission parameters of a transmitter of an underwater communication device |
| DE102018003299.0 | 2018-04-24 | ||
| PCT/EP2019/059795 WO2019206740A1 (en) | 2018-04-24 | 2019-04-16 | Method for adjusting a transmission parameter of a transmitter of an underwater communication device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2019259866A1 AU2019259866A1 (en) | 2020-09-03 |
| AU2019259866B2 true AU2019259866B2 (en) | 2021-06-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| AU2019259866A Active AU2019259866B2 (en) | 2018-04-24 | 2019-04-16 | Method for adjusting a transmission parameter of a transmitter of an underwater communication device |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP3785248B1 (en) |
| AU (1) | AU2019259866B2 (en) |
| DE (1) | DE102018003299B3 (en) |
| WO (1) | WO2019206740A1 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012162655A1 (en) * | 2011-05-26 | 2012-11-29 | Drexel University | Joint papr reduction and rate adaptive ultrasonic ofdm physical layer for high data rate through-metal communications |
| WO2016164146A2 (en) * | 2015-03-16 | 2016-10-13 | Lockheed Martin Corporation | Apparatus and method for increased data rates in underwater communications using orbital angular momentum |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5018114A (en) | 1988-12-13 | 1991-05-21 | The United States Of America As Represented By The Secretary Of The Navy | Adjustable frequency diversity acoustic communications system |
| US20050088916A1 (en) | 2001-12-30 | 2005-04-28 | Weiqing Zhu | Water acoustic coherently communication system and signal processing method having high code rate, low probability of error |
| CN107612629A (en) | 2017-10-19 | 2018-01-19 | 厦门大学 | A kind of hidden underwater acoustic communication method based on environment sensing |
-
2018
- 2018-04-24 DE DE102018003299.0A patent/DE102018003299B3/en not_active Expired - Fee Related
-
2019
- 2019-04-16 EP EP19718343.7A patent/EP3785248B1/en active Active
- 2019-04-16 AU AU2019259866A patent/AU2019259866B2/en active Active
- 2019-04-16 WO PCT/EP2019/059795 patent/WO2019206740A1/en not_active Ceased
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012162655A1 (en) * | 2011-05-26 | 2012-11-29 | Drexel University | Joint papr reduction and rate adaptive ultrasonic ofdm physical layer for high data rate through-metal communications |
| WO2016164146A2 (en) * | 2015-03-16 | 2016-10-13 | Lockheed Martin Corporation | Apparatus and method for increased data rates in underwater communications using orbital angular momentum |
Also Published As
| Publication number | Publication date |
|---|---|
| DE102018003299B3 (en) | 2019-05-02 |
| AU2019259866A1 (en) | 2020-09-03 |
| WO2019206740A1 (en) | 2019-10-31 |
| EP3785248B1 (en) | 2022-03-16 |
| EP3785248A1 (en) | 2021-03-03 |
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