Volume||4||Issue||04||April-2016||Pages-5244-5251||ISSN(e):2321-7545
Website: http://ijsae.in
DOI: http://dx.doi.org/10.18535/ijsre/v4i04.22
An Ultrasonic Sensor Based Low-Power AcousticModem for Underwater Communication
Authors
Jagdale M.R.1, Puranik V.G.2
1
PG student of Department of Electronics & Communication Engineering
Bhivarabai Sawant Institute of Technology& Research, Wagholi Pune, Maharashtra, India
2
Associate Professor, Department of Electronics & Communication Engineering
Bhivarabai Sawant Institutes of Technology & Research, Wagholi Pune, Maharashtra, India
Email- madhuri3jagdale@gmal.com vishalpura@gmail.com
ABSTRACT:
There is a growing interest in the usage of underwater networked structures for oceanographic applications.
These networks frequently depend upon acoustic communication, which poses some of demanding situations
for reliable data transmission. Commercial underwater modems that do exist have been layout for sparse,
lengthy range software as opposed to for small dense, sensor nets. The modulation method like ASK. This
design makes use of industrial ultrasonic transducer of two hundred kHz bandwidth. Massage from
transmitter can be displayed in visual format as well as it may be analyzed the usage of one of a kind
simulation gear at base station. This paper offers the layout attention, implementation information and
demanding situations in layout attention.
Keywords: Field Programmable Gate Array, Acoustic modem, ASK modulation techniques etc….
1. INTRODUCTION
Creation current advances in processors, reminiscence, and radio generation have made clever, tiny, and
cheap nodes possible. Wireless sensor networks composed of these nodes may be utilized in promising
community architectures. These sensors also gather a number of beneficial information in an unattended
manner. Programs of underwater sensor networks are composed of environmental monitoring, disaster
prevention and aid detection. Because the importance of those packages has currently grown, underwater
sensor networks made of sensor nodes must be in addition investigated. But, little studies have been
conducted in growing the underwater sensor node with verbal exchange functionality.
In an underwater environment, common RF-primarily based verbal exchange is not appropriate due to
statistics. The primary reality is that radio waves require large antennae and excessive transmission power.
the other fact is that the Berkeley Mica 2 Motes, the most famous experimental platform, have been
pronounced to have a transmission range of 120cm in underwater at 433MHz. therefore, we've concluded
that underwater communication has to use an acoustic or ultrasonic wave in preference to a radio wave.
1.1 Traits of underwater acoustic sensor community:
It uses acoustics waves, electromagnetic waves or optical waves:
Transmission loss: it is related to attenuation and Geometric spreading that is proportional to distance and
impartial of frequency.
Noise: It of two type guy made noise and ambient noise. Multipath: a couple of propagation reason to
degradation of acoustic communication sign due to (ISI) Inter symbol Interference.
Doppler unfolds: It reasons degradation in overall performance of virtual communication. It generates
outcomes: a easy frequency translation and continues spreading of frequency
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The underwater modem consists of 3 major components as underwater transducer, analog transceiver and
digital platform for control and signal processing .The transducer is an ultrasound sensor for dependable
verbal exchange. The sensor has frequency of 200 kHz and it has excessive performance and excessive
reliability. The analog transceiver includes a high energy transmitter and a pretty sensitive receiver each of
that are optimized to function inside the transducer resonance frequency variety. The transmitter is
answerable for amplifying the modulated signal from the virtual hardware platform and sending it to the
transducer in order that it is able to be transmitted via the water. The receiver amplifies the signal that is
detected with the aid of the transducer so that the digital hardware platform can effectively demodulate the
sign and analyze the transmitted statistics. Due to its high linearity, the transmitter may be used with any
modulation method that can be programmed into the virtual hardware platform.
The main purpose of a communication system is to transfer information from a source to a Destination. A
message signal containing information is used to control parameters of a carrier signal i.e. the information is
embedded onto the carrier. The carrier could either a sinusoidal wave or a pulse train. At the destination the
carrier plus message must be demodulated so that the message can be received.
2. BLOCK DIAGRAM OF ACOUSTIC MODEM
An Acoustic Transmitter and an Acoustic Receiver Details about the ultrasonic transmitter and receiver are
explained in which we can understand the basic function of Acoustic Transmitter and Receiver.
Fig.1 Block diagram of acoustic modem
The ultrasonic transmitter consists of three components: a frequency generator, an amplifier, and an
ultrasonic sensor. The frequency generator makes a forty kHz frequency and uses an ASK
modulation/demodulation technique that mixed an on-off voltage degree with a carrier wave. Then, the
modulated signals in the frequency generator are dispatched to the amplifier. The amplifier amplifies these
enter alerts. Ultrasonic sensor pressure circuit: The inverter is used for the power of the ultrasonic sensor.
For more transmission electric power, join inverters in parallel .The segment with the voltage to use to the
fine terminal and the terrible terminal of the sensor has been 180 ranges difference. Because it gives the
direct cutting-edge with the capacitor, about two instances of voltage of the inverter output are implemented
to the sensor the voltage level of the amplified indicators is "6V <" +6V.
Finally, the ultrasonic sensor transmits these amplified signals. The ultrasonic receiver is composed of five
components: an ultrasonic sensor, an amplifier, an envelope detector, and two comparators. The ultrasonic
sensor receives the transmitted indicators and sends them to the amplifier. Because the received indicators
are a minute sign, to system them inside the subsequent step, they need to be amplified. So, the amplifier
amplifies the obtained indicators. Then, the comparator removes the noise from the amplified indicators and
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sends the indicators to the envelope detector. The envelope detector detects the authentic indicators from the
amplified alerts.
The principle purpose of a conversation device is to switch records from a supply to a vacation spot. A
message sign containing records is used to control parameters of a carrier signal i.e. the information is
embedded onto the provider. The carrier may want to both a sinusoidal wave or pulses teach. On the
vacation spot the provider plus message should be demodulated so that the message can be acquired.
ASK modem:
The ASK modem‟s time and frequency parameters which were selected based on the properties of the
transducer. The „mark‟ frequency represents the frequency used to represent a digital „1 ‟ when converted to
baseband and the „space‟ frequency represents the frequency used to represent a digital „0‟ when converted
to baseband. The sampling frequency is used for sending and receiving themodulated waveform on the
carrier frequency while the baseband frequency is used for all baseband processing.
Table 1. ASK modem parameter
3. ULTRASOUND SENSORS:
The transducer is the device that converts electrical energy to/from acoustic energy, which is equivalent to
the antenna in radios. The T40-16 and R40-16 are matched pair ultrasonic transmitter and receiver
respectively operated at 40 KHz center frequency with 16mm diameter. This transducer utilizes the
piezoelectric properties of engineering ceramic that provides high sound. Pressure and high sensitivity
Specifications of sensor:
It is dual use i.e. Transreceiver
High perforamce, high realiability
Diameter:16mm.
Centeral frequency (KHz): 200.0 + 20
Bandwidth (-6db): 200KHz
Receiving sensitivity at 20cm: -56db
Range (m): 0.2 -1.2
Resolution: 2mm
Capacitance :380pF
Operating Temperature: -200 – 700C
Storage Temperature: -30-800C
These sensors are small in size and simple to use. It doesn‟t need any high security measures. Also it can be
automated with the controller or FPGA. Capacitive transducer act as both transmitter and receiver for
communication.
Sensor is of higher efficiency and has very high reliability. These are safe for use with simple operation.
This can be interfaced with the display devices easily. They can perform easily as they are small in size.
Ultrasound waves are more noise free than the other waves of communication.
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Fig. 2. Ultrasonic sensor
4. CIRCUIT DIAGRAM:
Fig. 3 Circuit diagram of acoustic modem
5. HW/ SW PLATFORM
Papilio One XC3s250 Spartan3 we can be the usage of. Arduino IDE we will use and Language of
programming is relatively exceptional than VHDL however it ultimately gets converted into Bit document
which can be loaded into FPGA. This IDE better handles floating factors and could provide u higher effects
that why we have selected this Spartan-3E FPGA family.
A. Spartan-3E FPGA Family
Fig.4 Kitsetup XC3s250 Spartan3
Specifications
 Densities up to 33,192 logic cells, including optional shift register or distributed RAM support
 Efficient wide multiplexers, wide logic
 Fast look-ahead carry logic
 Enhanced 18 x 18 multipliers with optional pipeline
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








IEEE 1149.1/1532 JTAG programming/debug port
Hierarchical Select RAM™ memory architecture
Up to 648 Kbits of fast block RAM
Up to 231 Kbits of efficient distributed RAM
Up to eight Digital Clock Managers (DCMs)
Clock skew elimination (delay locked loop)
Frequency synthesis, multiplication, division
High-resolution phase shifting
Wide frequency range (5 MHz to over 300 MHz) Eight global clocks plus eight additional clocks per
each half of device, plus abundant low-skew routing.
B. Arduino
Arduino it's far a single board microcontroller supposed used for interactive items or environments more
available. Open supply hardware board designed around an eight-bit Atmel AVR microcontroller, or a 32-bit
Atmel ARM is most important block of board. Current models consists of USB interface, for connect
numerous extension forums it provide 6 analog pins for enter, as well as 14 digital I/O pins.
1) Hardware: An Arduino board includes an Atmel 8-bit AVR microcontroller with complementary
components to facilitate programming and incorporation into other circuits. Some shields talk with the
Arduino board without delay, however many shields are for my part addressable, permitting many shields to
be stacked and used in parallel. ReliableArduinos have used the mega AVR collection of chips. A boot
loader simplifies uploading of packages to programmer an Arduino's microcontroller with the on-chip flash
reminiscence.
2) Software program: The Arduino integrated improvement surroundings (IDE) is a move-platform
application used programming language as Java, and is derived from the IDE for the Processing
programming language and the Wiring projects. It‟s far used to introduce programming beginners surprising
with software program improvement. It includes a code editor. The Arduino IDE comes with a software
library known as Wiring, which makes many commonplace input/output operations a good deal simpler.
C. Terminal: Terminal emulation application for RS-232: useful and small terminal emulation application
for the Serial port verbal exchange. Its makes use of seven com ports, you may use Transmit Macros. It is
com port development device Terminal is easy serial port (COM) terminal emulation software. For
communicating specific devices terminal makes use of. For serial verbal exchange applications, it's far very
useful debugging tool.
Features:  Without set up, best unmarried and small .exe record ~300KB.
 simple record send -Rx and TX characters counter
 baud price up to 256kbps & custom baud price as much as 64 COM ports -log to document (hex &
string)
 scripting (with graph/visualization guide)
 Remote manipulate over TCP/IP telnet -run applications from macro commands.
6. RESULTS:
Test Environment for Underwater Data Communication:
To test we have used an Aquarium for Underwater data communication. The test environment for this
acoustic data experiment setup used as a fixed two sensors which is act as transmitter sensor (in fig. shows
input transducer) on one side and another is act as receiver sensor (in fig. shows output transducer) and
water as transmission medium.
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It transmit any alphabet 8-bit data from transmitter and at receiver receive that data here, one example is
character „A‟ is transmitted at transmitter and it work from transmitter to receiver to give output waveform
in each block the result shown in below: yellow color waveform indicate as transmit data and blue
waveform indicate as receiver data.
Fig. 5 Water as transmission medium and the ultrasonic transducer setup
The communication experiment is done in following steps from transmitter part to receiver part. Data
transmitted in the laptop it contain serial port. Digital data transmit from transmitter side sensor. The
transmitted signal propagated through the water. Receiver receives this digital data at the receiver side
sensor. Finally this signal is in digital signal and displayed on the Terminal simulation programmer window.
Fig. 6 Snapshot of wave forms of transmitter & receiver
Result display on terminal software:
Here, sending message to transmitter is WELCOME TO PUNE IN JSPEM COLLAGE WAGHOLI it
receive at receiver side of modem
Fig. 6.1 Snapshot of input on Terminal (Message displayed at transmitter)
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Fig 6.2. Snapshot of output on Terminal (Message displayed at receiver)
7. CONCLUSIONS:
Through related work, we knew the requirement that the underwater sensor networks must perform the
acoustic communication. According to this requirement, this research with regard to an acoustic modem has
significant meaning when performing acoustic communication. However, the hardware to support acoustic
communication did not exist at all prior to our work. This work developed an acoustic modem as hardware
to perform acoustic communication.
Thus, the advantages of our acoustic modem are as follows. First, our acoustic modem is a low- powered
acoustic modem. In the energy consumption perspective, our modem was the best of all the others. Second,
our modem is a low cost based acoustic modem with the capability of digital data communication. Because
there had been no prior existing modem with this capability based on low-cost, our modem is significant in
this regard.
Acknowledgement
The authors would like to graciously thank Principal and Dr. Angle sir Head of the Department BSIOTR
PUNE, for their extended support in project. Finally I would like to thank V.G. Puranik, Associate professor
BSIOTR PUNE, who has provided me with the best knowledge about the project.
REFERENCES
1. Heungwoo Nam &Sunshin An, Low Power Acoustic Modem for UWC in UWSN, Korea University,
Anam-dong, Sungbuk-gu, seoul, korea, Post Code-136701.
2. MilicaStojanovic, Underwater Acoustic Communication, North Eastern University, Boston, MA
021115.
3. B.Benson, Y.Li, R.Kastner and B.Faunee, K.Domand, D.Kimball, C.Schurgers, “Design of Low cost
UWAM for Short Range Sensor Network ” LA Jolla, LA92093.
4. Ian F.Akyildiz, Dario Pompili and TommaroMelodia, Underwater Acoustic Sensor Networks:
Research Challenges, Atlanta, GA 30332, USA.
5. Akyildiz, I.F., Pompili, D., Melodia, T.: Underwater Acoustic Sensor Networks: Research
Challenges. Elsevier‟s Journal of Ad Hoc Networks 3(3), 257–281 (2005)
6. Benthos,
Inc.,
Fast
And
Reliable
Access
To
Undersea
Data,
http://www.benthos.com/pdf/Modems/ModemBrochure.pdf
7. Link Quest, Inc., Underwater Acoustic Modems, http://www.link-quest.com/html/uwm hr.pdf
8. ya, Engel, J., Chen, J., Fan, Z., Liu, C.: CORAL: Miniature Acoustic Communication Subsystem
Architecture for Underwater Wireless Sensor Networks. In: The 4th IEEE International Conference
on Sensors (October 2005)
Jagdale M.R. , Puranik V.G. IJSRE Volume 4 Issue 4 April 2016
Page 5250
9. Zhang, J., Huang, Z., Liu, X.: Acoustic Communication in Wireless Sensor Networks. In: CS651,
Wireless Sensor Networks, pp. 1–8 (December 2005)
10. Crossbow Technologies, Inc., http://www.xbow.com/ Wills, J., Ye,W., Heidemann, J.: Low-Power
Acoustic Modem for Dense Underwater Sensor Networks. In: Proceedings of the First ACM
International Workshop.
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