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Data integrationin
Multicarrier Reflectometry Sensorsby
Afshin Edrissi
Introduction
• What is a Smart Sensor?
Introduction
• Important to detect faults to prevent hazards
Purpose and Function
• Why Data communication?– Communicate to the outside world– Increase the capability of the sensors– Expanding the capabilities to new
applications
Fault located
Info transmitted to pilot
Purpose and Function
• Example – Real-time feedbackin emergencies
Purpose and Function
sTe
Project Design
• Design Specification:– Designed for up to 100 ft cables– Can operate without interference to
existing systems– Uses the unused portion of frequency
spectrum
Project Design
• Simulation– Matlab and Simulink– Xilinx ISE and Modelsim
• Implementation– Xtreme DSP
• Analog to Digital Converter• Digital to Analog Converter• Field Programmable Gate Array (FPGA)• LEDs and other analog components
Project Design
• Goals– Digital Signal Processing (DSP)– Minimum of 2kHz per data channel– Minimum of 24 real-time adjustable
channels– Adjustable in frequency spectrum
Data Integration
• Possible integration methods– Use the MCR waves to transfer data
• High hardware and software cost• Difficult to implement• Lower accuracy on the detected faults
Data Integration
• Possible integration methods– Use the unused frequency spectrum
• More beneficial and cost effective• Many algorithms to modulate
– ASK– FSK– BPSK– Many more to achieve high data rate
ω
64 MCR
6447448
1ω Nω
DataChannels
64748
Data Integration• Overall system
Data Integration
• Pulse shaping (hamming)– Filter to limit the
frequency spectrum– Removes high freq
components of coded data
2000 4000 6000 8000 10000-1.5
-1
-0.5
0
0.5
1
1.5
Samples
Am
plitu
de
Time domain
0 0.2 0.4 0.6 0.8-20
-10
0
10
20
30
40
50
60
Normalized Frequency (×π rad/sample)
Mag
nitu
de (d
B)
Frequency domain
Data Integration
• Modulator– Shifts the signal in
frequency spectrum
2000 4000 6000 8000 10000-300
-200
-100
0
100
200
300
SamplesA
mpl
itude
Time domain
0 0.2 0.4 0.6 0.840
50
60
70
80
90
100
110
120
Normalized Frequency (×π rad/sample)
Mag
nitu
de (
dB)
Frequency domain
Data Integration
• Digital to Analog Converter– Converts to analog in
order to transmit
3.27 3.28 3.29 3.3 3.31 3.32 3.33 3.34
-150
-100
-50
0
50
100
150
-8.0180, 8.6319, 24.2043, 31.9007, 27.4103, 11.0809, …
Data Integration
• Low pass filter– Removes high freq– smooth signal– Uses lower spectrum
3.27 3.28 3.29 3.3 3.31 3.32 3.33 3.34
-150
-100
-50
0
50
100
150
Data Integration
• Anti-Aliasing Filter– Limits the freq
spectrum to Nyquist Freq of sampling
0 0 . 1 0 . 2 0.3 0.4 0 . 5 0 . 6 0.7 0.8 0.92 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
1 1 0
1 2 0
Normal ized Frequency (× π rad/sample)M
agni
tude
(dB
)
F requency domain
Data Integration
• Automatic Gain Control– Signal is not too small for
the sampler– Signal is not saturated for
the sampler3.3 3.32 3.34 3.36 3.38 3.4
-1-0.875-0.75
-0.625-0.5
-0.375-0.25
-0.1250
0.1250.25
0.3750.5
0.6250.75
0.8751
3.3 3.32 3.34 3.36 3.38 3.4-1
-0.875-0.75
-0.625-0.5
-0.375-0.25
-0.1250
0.1250.25
0.3750.5
0.6250.75
0.8751
3.3 3.32 3.34 3.36 3.38 3.4-1
-0.875
-0.75
-0.625
-0.5
-0.375
-0.25
-0.125
0
0.125
0.25
0.375
0.5
0.625
0.75
0.875
1
Data Integration
• Sampling(Analog to Digital Converter)
– Brings the Signal for digital processing
-8.0180, 8.6319, 24.2043, 31.9007, 27.4103, 11.0809, …
3 .26 3 .27 3.28 3.29 3 .3 3.31 3.32 3 .33 3 .34 3 .35-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Data Integration
• Demodulator– Shifts the freq– DC and 2xCarrier
1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-300
-200
-100
0
1 0 0
2 0 0
3 0 0
Samples
Am
plitu
de
T ime domain
0 0 . 2 0 . 4 0.6 0 . 84 0
5 0
6 0
7 0
8 0
9 0
1 0 0
1 1 0
1 2 0
Normal ized Frequency ( ×π rad/sample)
Mag
nitu
de (d
B)
F requency domain
Data Integration
• Low pass filter– Removes the high freq
components– Cleans up the signal
1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-150
-100
- 5 0
0
5 0
1 0 0
1 5 0
Samples
Am
plitu
de
T ime domain
0 0 . 2 0 . 4 0.6 0 . 83 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
1 1 0
1 2 0
Normal ized Frequency ( ×π rad/sample)
Mag
nitu
de (d
B)
F requency domain
Data Integration
• Decision Circuitry– Removes the noise– Compares to zero and
produces clean digital output
1 2 3 4 5 6 7 8 9 10-1.5
-1
-0.5
0
0.5
1
1.5
Data Integration• Overall system
Conclusion
• Achievements– 28 Real-time adjustable channels– 6.1kHZ frequency separation– Adjustable in frequency spectrum location with
starting from 10MHz– Works up to 100 ft wires
Conclusion
• Open-ended design– New algorithms with minimal hardware cost– M-Array modulation– Spread Spectrum– Frequency Hopping– Serial to parallel transmission using many
channels– Many more…
Conclusion
• Some applications– Cars– Power lines– Computer cables– Networks– Any device that uses wires!
