acoustic_modem_pres

8/7/2019 Acoustic_Modem_Pres

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re essre ess

UnderwaterUnderwater

CommunicationsCommunications

NetworkNetworkECE Senior Design Team #88ECE Senior Design Team #88Spring-Fall 2007Spring-Fall 2007

Roy BehymerRoy BehymerKrenar JusufiKrenar Jusufi

Mary HoyerMary Hoyer

Advisor - Shengli ZhouAdvisor - Shengli Zhou


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OutlineOutline

BackgroundBackground

Project DescriptionProject Description

Technical SpecificationsTechnical Specifications TimelineTimeline

BudgetBudget


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Goal is to expand two-nodeGoal is to expand two-node

underwater, acoustic network tounderwater, acoustic network to

three-node relay network withthree-node relay network withmotion sensormotion sensor


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Packet Structure 64Packet Structure 64

bytesbytes

1 1 1 1 1 1 57 1

msgNe

xt

msgSrc

msgDe

st

msgSe

qNo

msgNo

Pack

msgUs

eful

msgDa

ta

msgErr


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Packet Structure 64Packet Structure 64

bytesbytes Next Hop AddressNext Hop Address

Source AddressSource Address

Destination AddressDestination Address Sequence NumberSequence Number

Number of PacketsNumber of Packets

Number of Bytes of Useful DataNumber of Bytes of Useful Data Data (57)Data (57)

Error CheckError Check


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TransmittingTransmitting

Destination and Source nodes comparedDestination and Source nodes compared If same, no message transmittedIf same, no message transmitted Otherwise determine next nodeOtherwise determine next node

Determine message length and number ofDetermine message length and number ofpackets needed.packets needed. Parse data if neededParse data if needed Determine number of useful bytes in lastDetermine number of useful bytes in last

packetpacket The new data string encompassing headerThe new data string encompassing header

information is processed.information is processed.


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ReceivingReceiving

Compare Destination and ComputerCompare Destination and Computer

info.info. Relay message if not at destinationRelay message if not at destination

Process remainder of message if atProcess remainder of message if at

destinationdestination Broken down using packet structureBroken down using packet structure

Display messageDisplay message


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Matlab Lessons LearnedMatlab Lessons Learned

Characters / Strings best handled via arraysCharacters / Strings best handled via arrays not as friendly as VBnot as friendly as VB

built-in functions not as versatilebuilt-in functions not as versatile

Start with structure and maintain it whileStart with structure and maintain it whiledeveloping codedeveloping code

Document codeDocument code

Document function and file dependenciesDocument function and file dependencies


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Breakdown ofBreakdown of

SendDataCallbackSendDataCallback

writefileTX converts symbols to ascii and writeswritefileTX converts symbols to ascii and writesinto fileinto file num2binmap finds binary equivalentnum2binmap finds binary equivalent

contReceiverv2 continuously monitors incomingcontReceiverv2 continuously monitors incomingdata, if trigger is met goes to autoautocorrdata, if trigger is met goes to autoautocorr

zTxRNSv2 processes and sends datazTxRNSv2 processes and sends data readfile converts ascii character to text to binaryreadfile converts ascii character to text to binary num2binmap finds binary equivalentnum2binmap finds binary equivalent CCQPSKencode performs coding on binary vector thenCCQPSKencode performs coding on binary vector then

QPSK mappingQPSK mapping insertnull insert null subcarriers and pilot tonesinsertnull insert null subcarriers and pilot tones synchcpofdm cyclic prefix-ofdmsynchcpofdm cyclic prefix-ofdm writefile converts symbols to ascii and writes to filewritefile converts symbols to ascii and writes to file

Writetodisp lets us know message was sentWritetodisp lets us know message was sent


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contReceiverv2contReceiverv2

analyzedata analyzes dataanalyzedata analyzes data autoautocorr auto correlation to find useful dataautoautocorr auto correlation to find useful data zRxV2 main receiver file, receives and processes datazRxV2 main receiver file, receives and processes data

CFOchjointestimation2 uses channel estimation to determineCFOchjointestimation2 uses channel estimation to determinecarrier frequency offsetcarrier frequency offset

removeqrtrdataV2 removes pilot tones and null subcarriersremoveqrtrdataV2 removes pilot tones and null subcarriers BERcount finds raw bit error rateBERcount finds raw bit error rate Ch_estimation provides time and frequency domain channelCh_estimation provides time and frequency domain channel

representationrepresentation dem_wi_decoder QPSK signals demodulationdem_wi_decoder QPSK signals demodulation binaryBER finds BER after decodingbinaryBER finds BER after decoding writefilewritefile converts symbols to ascii and writes into file converts symbols to ascii and writes into file


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GoalsGoals

a)a) Draw flow chart based on dependencyDraw flow chart based on dependencyreports of codesreports of codes

b)b) Give description of each functions and subGive description of each functions and sub

functionsfunctionsc)c) Delete files unusedDelete files unused

d)d) Combine small files into large file forCombine small files into large file fororganizationorganization

e)e) Clear variables before each run so there isClear variables before each run so there isless chance of failure in testingless chance of failure in testing

f)f) Put all parameters as global variablePut all parameters as global variable


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Motion SensorMotion Sensor

Need real-time, continuous data acquisitionNeed real-time, continuous data acquisition

MATLAB does not support our motion sensorMATLAB does not support our motion sensor

Solution: use LabView VI for interfaceSolution: use LabView VI for interface

Must convert LabView VI to MATLAB functionMust convert LabView VI to MATLAB function Math Interface ToolkitMath Interface Toolkit


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TimelineTimelineMonth Short Term

Goals

Long Range Goals

February Review / Research Three-node relay network in air with motion sensor

March Ordering parts (air)

April Hardware ModsSoftware Mods

May Review / Research Summer

June

July

August Underwater Testing Three-node relay network in water

September Debugging

Hardware ModsSoftware Mods

October Hardware Mod Three or four node full network in air and water withtwo motion sensors

November Software Mods

December Final Write-up and Demonstration


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BudgetBudget

Product Price

M-Audio Mobile Pre USB Audio Interface withPreamp (2)

$238.00

XLR Cable (2) $15.65

Audix TR-40 Microphones (2) $379.94

Microphone Stands (2) $23.94

Motion Sensors (2) $208.00

LabView Math Interface Toolkit (1) ~$100.00

Total ~$965.53


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ConclusionConclusion


Project DescriptionProject Description

Technical SpecificationsTechnical Specifications TimelineTimeline

BudgetBudget


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