Download - International Journal Of Scientific Research And

An Ultrasonic Sensor Based Low-Power AcousticModem for Underwater
Communication
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
[email protected]
2
Associate Professor, Department of Electronics & Communication Engineering
Bhivarabai Sawant Institutes of Technology & Research, Wagholi Pune, Maharashtra, India
[email protected]
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.
1.2 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.
Jagdale Madhuri R et al
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
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.
www.ijetst.in
Page 1
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.
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:
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 onoff 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 cuttingedge 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 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.
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.
ASK modem:
The ASK modem’s time and frequency parameters
which were selected based on the properties of the transducer.
Jagdale Madhuri R
Fig. 2. Ultrasonic sensor
Page 2
4. Circuit diagram:
 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.
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
 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
Jagdale Madhuri R
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 RS232: 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.
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.
Page 3
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. 7. Snapshot of output on Terminal (Message displayed
at receiver)
Fig. 6 Snapshot of wave forms of transmitter & receiver
ACKNOWLEDGEMENT
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
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.
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
Fig. 6. Snapshot of input on Terminal (Message displayed at
Challenges, Atlanta, GA 30332, USA.
transmitter)
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)
Jagdale Madhuri R
Page 4
6) Benthos, Inc., Fast And Reliable Access To Undersea Data, 9) Zhang, J., Huang, Z., Liu, X.: Acoustic Communication in
http://www.benthos.com/pdf/Modems/ModemBrochure.pdf
Wireless Sensor Networks. In: CS651, Wireless Sensor
7) Link Quest, Inc., Underwater Acoustic Modems,
Networks, pp. 1–8 (December 2005)
http://www.link-quest.com/html/uwm hr.pdf
10) Crossbow Technologies, Inc., http://www.xbow.com/ Wills,
8) ya, Engel, J., Chen, J., Fan, Z., Liu, C.: CORAL: Miniature
J., Ye,W., Heidemann, J.: Low-Power Acoustic Modem for
Acoustic Communication Subsystem Architecture for
Dense Underwater Sensor Networks. In: Proceedings of the
Underwater Wireless Sensor Networks. In: The 4th IEEE
First ACM International Workshop
International Conference on Sensors (October 2005)
Jagdale Madhuri R
Page 5