Wireless Underwater Communications Network

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Wireless Underwater Communications Network

• ECE Senior Design Team 88
• Spring-Fall 2007
• Roy Behymer
• Krenar Jusufi
• Mary Hoyer
• Advisor - Shengli Zhou

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Outline

• Background
• Project Description
• Technical Specifications
• Timeline
• Budget

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Background

• Goal is to expand two-node underwater, acoustic
  network to three-node relay network with motion
  sensor

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Packet Structure 64 bytes
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Packet Structure 64 bytes

• Next Hop Address
• Source Address
• Destination Address
• Sequence Number
• Number of Packets
• Number of Bytes of Useful Data
• Data (57)
• Error Check

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Transmitting

• Destination and Source nodes compared
• If same, no message transmitted
• Otherwise determine next node
• Determine message length and number of packets
  needed.
• Parse data if needed
• Determine number of useful bytes in last packet
• The new data string encompassing header
  information is processed.

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Receiving

• Compare Destination and Computer info.
• Relay message if not at destination
• Process remainder of message if at destination
• Broken down using packet structure
• Display message

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Matlab Lessons Learned

• Characters / Strings best handled via arrays
• not as friendly as VB
• built-in functions not as versatile
• Start with structure and maintain it while
  developing code
• Document code
• Document function and file dependencies

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Breaking the Code

• Transceiver_RNS main, open this to run program
• SendDataCallback this is used by
  Transceiver_RNS to send signal
• SelectRecordCallback this is used by
  Transceiver_RNS to receive signal
• contReceiverv2 same as SendDataCallback
• writefileCLEAR clears writefile

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Breakdown of SendDataCallback

• writefileTX converts symbols to ascii and
  writes into file
• num2binmap finds binary equivalent
• contReceiverv2 continuously monitors incoming
  data, if trigger is met goes to autoautocorr
• zTxRNSv2 processes and sends data
• readfile converts ascii character to text to
  binary
• num2binmap finds binary equivalent
• CCQPSKencode performs coding on binary vector
  then QPSK mapping
• insertnull insert null subcarriers and pilot
  tones
• synchcpofdm cyclic prefix-ofdm
• writefile converts symbols to ascii and writes
  to file
• Writetodisp lets us know message was sent

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contReceiverv2

• analyzedata analyzes data
• autoautocorr auto correlation to find useful
  data
• zRxV2 main receiver file, receives and
  processes data
• CFOchjointestimation2 uses channel estimation
  to determine carrier frequency offset
• removeqrtrdataV2 removes pilot tones and null
  subcarriers
• BERcount finds raw bit error rate
• Ch_estimation provides time and frequency
  domain channel representation
• dem_wi_decoder QPSK signals demodulation
• binaryBER finds BER after decoding
• writefile converts symbols to ascii and writes
  into file

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Goals

• Draw flow chart based on dependency reports of
  codes
• Give description of each functions and sub
  functions
• Delete files unused
• Combine small files into large file for
  organization
• Clear variables before each run so there is less
  chance of failure in testing
• Put all parameters as global variable

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Motion Sensor

• Need real-time, continuous data acquisition
• MATLAB does not support our motion sensor
• Solution use LabView VI for interface
• Must convert LabView VI to MATLAB function
• Math Interface Toolkit

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Timeline
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Budget
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Conclusion

• Background
• Project Description
• Technical Specifications
• Timeline
• Budget

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Any Questions???