CN105187133B - Carrier frequency self-adaptive underwater communication method and device - Google Patents
Carrier frequency self-adaptive underwater communication method and device Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 18
- 238000010295 mobile communication Methods 0.000 claims abstract description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 55
- 230000003044 adaptive effect Effects 0.000 claims description 10
- 230000005540 biological transmission Effects 0.000 claims description 10
- 238000012790 confirmation Methods 0.000 claims description 9
- 238000005259 measurement Methods 0.000 claims description 8
- 238000012545 processing Methods 0.000 claims description 5
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Abstract
The invention relates to a carrier frequency self-adaptive underwater communication method and a device thereof, wherein an underwater mobile communication terminal is used for communicating with a relay platform through an underwater acoustic channel; the data obtained by the relay platform is communicated with the land communication device through a wired channel or a wireless channel, and the acquired information is sent to the land communication device for storage and analysis. The invention enables the carrier frequency value to be configurable, and can be adjusted according to the specific situation of the channel so as to adapt to the characteristics of the channel; the invention has stable performance, high precision, high frequency conversion speed, continuous phase output when the frequency is changed and strong anti-interference capability.
Description
Technical field
The present invention relates to field of underwater acoustic communication, especially a kind of adaptive subsurface communication method of carrier frequency and its device.
Background technology
Actual underwater acoustic channel is extremely complex, and it has the water surface and water-bed two interfaces.Due to temperature, salinity and static pressure
Influence, the different depth velocity of sound is different in water, there is velocity of sound vertical distribution, and sound wave can be made to produce refraction.Up-and-down boundary
Reflection and the refraction in water cause actual underwater acoustic channel not to be single approach channel but multipath channel.Done to reduce multipath
The influence disturbed, generally using non-coherent detection methods.Frequency shift keying communication mode can be realized using non-coherent detection methods.Cause
This, frequency shift keying is widely used in underwater sound communication.
For traditional frequency shift keying communication mode being applied in underwater sound communication, carrier frequency is fixed, and this is to suitable
Underwater acoustic channel complicated and changeable under different marine environment is answered to cause significant limitation.Acoustic propagation under water is main to be damaged by propagating
The time-varying and space-variant of mistake, noise and channel are determined.The characteristic of propagation loss, noise and channel is by the environment residing for channel and position
Influence is put than larger.Such as, the acoustic propagation characteristic and characteristic of channel difference of inshore region and deep-sea area are just very big.The underwater sound leads to
Letter link can be divided into five classes according to distance：Overlength, length, medium, short, extremely short journey channel.To an operating distance in 10-100km
Long-haul system speech, bandwidth is limited in several kHz.The bandwidth of moderate distance (1-10km) system is in tens of KHz magnitude.Only
Have under conditions of distance is less than 100m, can just obtain the bandwidth more than 100kHz.Considering underwater acoustic channel, these are complicated and changeable
Situation and characteristic, the carrier frequency value of this subsurface communication method can be adjusted according to operating distance, with the spy of adaptive channel
Property.
The content of the invention
The technical problem to be solved in the present invention is：Propose the water that a kind of carrier frequency value can be adjusted according to operating distance
Lower communication means and its device, to adapt to underwater acoustic channel characteristic complicated and changeable.
The technical solution adopted in the present invention is：A kind of adaptive subsurface communication method of carrier frequency, under water mobile communication
Terminal is communicated with relaying platform by underwater acoustic channel；The data that relaying platform is obtained pass through wire message way or wireless channel again
Communicated with land communicator, giving land communicator by the information of collection is stored and analyzed, specifically include with
Lower step：
1) when mobile communication terminal is initially devoted to precalculated position in water under water, according to the distance foundation with relaying platform
Data determine that initial carrier frequency is communicated；
2) mobile mobile communication terminal under water, it is whole to mobile communication under water under water in mobile communication terminal moving process
Hold and measured with relaying the distance of platform；
3) according to step 2) distance that measures determines carrier reference and carries out the mark frequency and spacing of 2FSK communications
Frequency；
4) after step 3) in all new communication frequencys determine after, mobile communication terminal sends to relaying platform and reported under water
Proclamation knows new communication frequency, and waits relaying platform to send confirmation message；Receive after confirmation message, under water mobile communication terminal
Communication frequency is changed to new communication frequency with relaying platform；
5) with step 4) the middle new communication frequency determined is communicated, and change the carrier frequency of modulator and the phase of demodulator
Related parameter.
Further, step 2 of the present invention) in measuring method be：Message is collected by transmission time information to enter
Row measurement, will be written in message at the time of sending message in the way of timestamp；By formula
Measure the distance of mobile communication terminal and relaying platform under water:L=340td；Wherein, message is from mobile communication terminal under water along just
The transmission timestamp for sending message to path is Tz1, the time of reception for the message that relaying platform is received along forward path is Tz2；
The time of reception that mobile communication terminal receives message along reverse path under water is Tf1, relay platform and send message along reverse path
Transmission timestamp is Tf2；The propagation delay time of mobile communication terminal and relaying platform is t under waterd。
Further say, step 3 of the present invention) in, mobile communication terminal under water is calculated using linear interpolation
It is with relaying the carrier reference corresponding to the distance of platform：Wherein, la、lbFor setting
Reference range, fa、fbFor corresponding carrier frequency, and la＜ l ＜ lb。
Meanwhile, the present invention also provides the device used in a kind of adaptive subsurface communication method of carrier frequency, including under water
Mobile communication terminal, relaying platform and land communicator；Described mobile communication terminal under water passes through water with relaying platform
Acoustic channel is communicated；The data that relaying platform is obtained are led to by wire message way or wireless channel with land communicator again
Letter, gives land communicator by the information of collection and is stored and analyzed；Described mobile communication terminal under water includes measurement
Module, control module, coding and decoding module, modulator, demodulator and underwater acoustic transducer；Described measurement module will measure or
Obtained underwater information is monitored, control module is sent to；Described control module is encoded data by coding and decoding module,
Then 2FSK digital modulations are carried out by modulator；2FSK becomes acoustical signal by underwater acoustic transducer by data signal, passes through the underwater sound
Transmission；After the order and confirmation that described relaying platform is sent are transmitted through underwater acoustic channel, by underwater acoustic transducer by
Voice signal is changed into electric signal, through digital demodulation, and control module is sent to after decoding.
Further, described modulator tires out including FREQUENCY CONTROL word register group, alternative data selector, phase
Plus device, sine ROM look-up tables, D/A converter and low pass filter；Single-chip microcomputer is write to described FREQUENCY CONTROL word register group
Enter and the frequency control word corresponding to FSK carrier frequencies；The described alternative data selector output phase of baseband signal control
Input of the carrier frequency control word signal answered to phase accumulator；Described D/A converter exports low-pass filtered device and obtained
To corresponding fsk signal.
Further say, described demodulator includes underwater acoustic transducer acoustical signal reception device, the reception being sequentially connected
Circuit, digital waveform harvester and signal processing apparatus；Described underwater acoustic transducer acoustical signal reception device will be received
Fsk signal through underwater acoustic transducer by acoustical signal be converted to after electric signal, received processing of circuit input digital waveform collection fill
Progress digital waveform collection is put, signal transacting is then carried out by described signal processor.
The beneficial effects of the invention are as follows：So that carrier frequency value is configurable, it can be adjusted according to the concrete condition of channel,
With the characteristic of adaptive channel；And inventive can be stablized, precision is high, frequency conversion speed fast, frequency shift when phase output
Continuously, strong antijamming capability.
Brief description of the drawings
The present invention is further described with reference to the accompanying drawings and examples.
Fig. 1 is the theory diagram that subsurface communication terminal is communicated with land communicator；
Fig. 2 is the functional block diagram of mobile communication terminal under water；
Fig. 3 is FSK modulation device functional block diagram；
Fig. 4 is the theory diagram of demodulator.
Embodiment
Presently in connection with accompanying drawing and preferred embodiment, the present invention is further detailed explanation.These accompanying drawings are simplified
Schematic diagram, only illustrates the basic structure of the present invention in a schematic way, therefore it only shows the composition relevant with the present invention.
The block diagram that subsurface communication terminal as shown in Figure 1 is communicated with land communicator；
In general, mobile communication terminal is measurement or detection means under water, for measuring or monitoring underwater information, such as temperature
Degree, pressure, sound etc..Platform is relayed as subsurface communication and the relay point of marine communication, can be fixed, as on bank
Fixing device；Can also be mobile, such as some relaying platforms are located on the lash ship moved.Mobile communication terminal is with water
Communicated after platform by underwater acoustic channel.The data for relaying platform acquisition are led to by wire message way or wireless channel with land again
T unit is communicated, and giving land communicator by the information of collection is stored and analyzed.
The functional block diagram of mobile communication terminal such as Fig. 2 under water.The underwater information that wherein measurement module measurement or monitoring are obtained,
Send control module to, control module is encoded data by coding module, 2FSK digital modulations then carried out by modulator,
2FSK becomes acoustical signal by underwater acoustic transducer by data signal, is transmitted by underwater acoustic channel, after repeated platform is received, will adopt
The information of collection is forwarded to land communicator and is stored and analyzed.The order and confirmation that relaying platform is sent are believed through the underwater sound
After road transmission, electric signal is changed into from voice signal by underwater acoustic transducer, through digital demodulation, control module is sent to after decoding.
The course of work is with step：
1st, when mobile communication terminal is initially devoted to precalculated position in water under water, according to the distance foundation with relaying platform
Empirical data determines that initial carrier frequency is communicated.
2nd, under water in mobile communication terminal moving process, the distance to mobile communication terminal under water and relaying platform is carried out
Measure, measuring method is：
Message is collected by transmission time information to measure, and will be written at the time of sending message in the way of timestamp
In message.Assuming that the transmission timestamp that message sends message from mobile communication terminal under water along forward path is Tz1, relay platform
The time of reception of the message received along forward path is Tz2；Mobile communication terminal receives the reception of message along reverse path under water
Moment is Tf1, the transmission timestamp that relaying platform sends message along reverse path is Tf2；If mobile communication terminal is with relaying under water
The propagation delay time of platform is td, the clock jitter of two nodes is Δ t；
Then
Tz2=Tz1+td+ Δ t formulas 1
Tf1=Tf2+td- Δ t formulas 2
As available from the above equation
Formula 3
Then now under water mobile communication terminal with relaying platform distance:L=340td
3rd, carrier reference is determined according to distance and carries out the mark frequency and space frequency of 2FSK communications.Determine method
For：
Several groups of typical range values and the corresponding carrier frequency used are selected first as reference range value and frequency
Value.Distance carrier frequency corresponding in the range of corresponding reference range is calculated using linear interpolation.Such as, reference range
la、lbCorresponding carrier frequency is respectively fa、fb, then the mobile communication terminal under water calculated according to linear interpolation is with
After platform apart from l (la＜ l ＜ lb) corresponding to carrier reference be：
On the basis of resulting reference frequency, appropriate adjustment is carried out, can obtain carrying out the mark frequency of 2FSK communications
And space frequency, such as mark frequency is 0.9f, and space frequency is 1.1f.
Below using reference range as 1Km, 10Km situation illustrates embodiment.It is 1Km, 10Km for reference range
Distance, according to underwater acoustic channel situation and empirical data, often select corresponding carrier frequency left for 50KHz or so and 10KHz
Right frequency is carrier reference.
According to above computational methods, for mobile communication terminal under water and relaying platform apart from l be 5Km in the case of, then
Corresponding carrier reference is：34KHz.Appropriate adjustment is carried out, can obtain carrying out the mark frequency and sky of 2FSK communications
Number frequency, such as mark frequency are 30.6KHz, and space frequency is 37.4KHz.
4th, after new communication frequency is determined, mobile communication terminal sends message to relaying platform and informs new traffic frequency under water
Rate, and wait relaying platform to send confirmation message.Receive after confirmation message, mobile communication terminal and relaying platform are to prepare under water
Change communication frequency is new communication frequency.
5th, communicated with new communication frequency, it is necessary to change the carrier frequency of modulator and the relevant parameter of demodulator.
FSK modulation device functional block diagram such as Fig. 3, principal functional structure is by phase accumulator, sine ROM look-up tables, D/A
Conversion, low pass filter, FREQUENCY CONTROL word register group, alternative data selector etc. are constituted.
Single-chip microcomputer writes and the frequency control word corresponding to FSK carrier frequencies to frequency register group；Assuming that being determined
New FSK carrier frequencies are respectively f0, f1, then produce corresponding frequencies frequency control word be respectively：K0For to f0/ 10 round, K1
For to f1/ 10 round.
Baseband signal control alternative data selector exports corresponding carrier frequency control word signal to phase accumulator
Input；According to DDS operation principle, D/A conversion outputs are low-pass filtered to can obtain corresponding fsk signal.
In specific implementation process, the scope that can set carrier frequency value is 100Hz-200KHz, frequency step 10Hz.With
The need for the parameter of upper frequency range and frequency step can meet most of actual underwater environment.
If K is frequency control word, selecting system clock fc=655.36KHz,
According to frequency stepIt is 16 to obtain N=16, i.e. phase accumulator word length.
Output frequencyThe scope for considering set carrier frequency value is 100Hz-
200KHz, then frequency control word span is 10≤K≤20000.
Assuming that determining that new FSK carrier frequencies are respectively that mark frequency is 30.6KHz, space frequency is 37.4KHz, then
Produce corresponding frequencies frequency control word be respectively：K0For 3060, K1For 3740.
The relevant parameter of the demodulator of mobile communication terminal under water and relaying platform need to be changed simultaneously.The principle frame of demodulator
Figure such as Fig. 4.Acoustical signal is converted to and carried out after electric signal, received processing of circuit by the fsk signal received through underwater acoustic transducer
Digital waveform is gathered, i.e. A/D conversions, then carries out signal transacting by digital signal processor.Signal transacting is completed by software, right
The situation of new frequency is changed in the fsk signal carrier frequency received, it is necessary to change the parameter of corresponding signal processing module, is such as filtered
The parameters such as the coefficient of device.
The embodiment of the simply present invention described in description above, the reality of various illustrations not to the present invention
Matter Composition of contents is limited, and person of an ordinary skill in the technical field can be to described in the past specific after specification has been read
Embodiment is made an amendment or deformed, without departing from the spirit and scope of the invention.
Claims (4)
1. a kind of adaptive subsurface communication method of carrier frequency, it is characterised in that：Mobile communication terminal leads to relaying platform under water
Underwater acoustic channel is crossed to be communicated；The data that relaying platform is obtained are entered by wire message way or wireless channel with land communicator again
Row communication, gives land communicator by the information of collection and is stored and analyzed, specifically include following steps：
1) when mobile communication terminal is initially devoted to precalculated position in water under water, according to the distance with relaying platform according to data
Determine that initial carrier frequency is communicated；
2) mobile mobile communication terminal under water, under water in mobile communication terminal moving process, to mobile communication terminal under water with
The distance of relaying platform is measured；
3) according to step 2) distance that measures determines carrier reference and carries out the mark frequency and space frequency of 2FSK communications；
4) after step 3) in all new communication frequencys determine after, mobile communication terminal sends message to relaying platform and accused under water
Know new communication frequency, and wait relaying platform to send confirmation message；Receive after confirmation message, mobile communication terminal is with water
Communication frequency is changed to new communication frequency after platform；
5) with step 4) the middle new communication frequency determined is communicated, and change the carrier frequency of modulator ginseng related to demodulator
Number；
Described step 2) in measuring method be：Message is collected by transmission time information to measure, and will send message
Moment is written in message in the way of timestamp；By formulaMeasure mobile communication under water whole
End and the distance of relaying platform:L=340td；Wherein, message sends the hair of message from mobile communication terminal under water along forward path
It is T to send timestampz1, the time of reception for the message that relaying platform is received along forward path is Tz2；Mobile communication terminal edge under water
The time of reception that reverse path receives message is Tf1, the transmission timestamp that relaying platform sends message along reverse path is Tf2；Water
The propagation delay time of lower mobile communication terminal and relaying platform is td。
2. a kind of adaptive subsurface communication method of carrier frequency as claimed in claim 1, it is characterised in that：Described step 3)
In, use linear interpolation calculate under water mobile communication terminal with relaying platform distance corresponding to carrier reference for：Wherein, la、lbFor the reference range of setting, fa、fbFor corresponding carrier frequency, and la＜ l
＜ lb。
3. the device used in a kind of adaptive subsurface communication method of carrier frequency as claimed in claim 1, it is characterised in that：
Including mobile communication terminal under water, relaying platform and land communicator；Described mobile communication terminal under water is flat with relaying
Platform is communicated by underwater acoustic channel；The data that relaying platform is obtained are communicated dress by wire message way or wireless channel with land again
Put and communicated, giving land communicator by the information of collection is stored and analyzed；Described mobile communication terminal under water
Including measurement module, control module, coding and decoding module, modulator, demodulator and underwater acoustic transducer；Described measurement module
The underwater information that will be measured or monitoring is obtained, sends control module to；Described control module is by data by coding and decoding module
Encoded, 2FSK digital modulations are then carried out by modulator；2FSK becomes acoustical signal by underwater acoustic transducer by data signal,
Transmitted by underwater acoustic channel；After the order and confirmation that described relaying platform is sent are transmitted through underwater acoustic channel, pass through the underwater sound
Transducer is changed into electric signal from voice signal, through digital demodulation, and control module is sent to after decoding；
Described modulator includes FREQUENCY CONTROL word register group, alternative data selector, phase accumulator, sine ROM and looked into
Look for table, D/A converter and low pass filter；Single-chip microcomputer writes and FSK carrier frequencies to described FREQUENCY CONTROL word register group
Frequency control word corresponding to rate；The described alternative data selector of baseband signal control exports corresponding carrier frequency control
Input of the word signal processed to phase accumulator；Described D/A converter exports low-pass filtered device and obtains corresponding FSK letters
Number.
4. a kind of adaptive underwater communication device of carrier frequency as claimed in claim 3, it is characterised in that：Described demodulator
Including underwater acoustic transducer acoustical signal reception device, receiving circuit, digital waveform harvester and the signal transacting being sequentially connected
Device；Described underwater acoustic transducer acoustical signal reception device changes acoustical signal the fsk signal received through underwater acoustic transducer
For electric signal, input digital waveform harvester carries out digital waveform collection after received processing of circuit, then by described letter
Number processor carries out signal transacting.
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| CN107124230B (en) * | 2017-04-25 | 2018-09-04 | 腾讯科技（深圳）有限公司 | Sound wave communication method, terminal and server |
| CN108809881B (en) * | 2018-05-02 | 2021-07-20 | 燕山大学 | Improved EXP3 algorithm-based underwater self-adaptive OFDM communication method |
| CN112152704B (en) * | 2019-06-28 | 2022-10-25 | Oppo广东移动通信有限公司 | Communication control method, communication control device, storage medium, and electronic apparatus |
| CN110336619B (en) * | 2019-07-05 | 2021-10-08 | 中国人民解放军海军大连舰艇学院 | Mobile communication equipment on sea |
| CN110601772A (en) * | 2019-09-20 | 2019-12-20 | 深圳市智慧海洋科技有限公司 | Communication method and device for connecting water network and underwater network |
| CN114442655A (en) * | 2020-11-04 | 2022-05-06 | 中国科学院沈阳自动化研究所 | ROV remote driving monitoring method based on satellite communication |
| CN114024595B (en) * | 2021-11-15 | 2023-06-06 | 湖南金龙智造科技股份有限公司 | Communication method and system for amphibious terminal |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101021562A (en) * | 2006-11-20 | 2007-08-22 | 重庆大学 | Method for ultrasonic distance measuring under low signal-to-noise ratio and range finder thereof |
| CN102546323A (en) * | 2010-12-14 | 2012-07-04 | 中国科学院声学研究所 | Peer-to-peer network based on underwater sound and radio mixed channel |
| CN103209224A (en) * | 2013-04-28 | 2013-07-17 | 上海海事大学 | P2P (peer-to-peer)-based underwater acoustic sensor network system and data transmission method thereof |
| CN103686602A (en) * | 2013-12-16 | 2014-03-26 | 广州舟之翼电子科技有限公司 | Ship wireless transmission control device and method |
Family Cites Families (1)
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| US9369214B2 (en) * | 2007-06-05 | 2016-06-14 | Robert Alan Fleming | Inter-diver signaling device and process |
-
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101021562A (en) * | 2006-11-20 | 2007-08-22 | 重庆大学 | Method for ultrasonic distance measuring under low signal-to-noise ratio and range finder thereof |
| CN102546323A (en) * | 2010-12-14 | 2012-07-04 | 中国科学院声学研究所 | Peer-to-peer network based on underwater sound and radio mixed channel |
| CN103209224A (en) * | 2013-04-28 | 2013-07-17 | 上海海事大学 | P2P (peer-to-peer)-based underwater acoustic sensor network system and data transmission method thereof |
| CN103686602A (en) * | 2013-12-16 | 2014-03-26 | 广州舟之翼电子科技有限公司 | Ship wireless transmission control device and method |
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