sensors and digital signal processing (dsp) part 2: dsp ... · sensors and digital signal...
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
EE 4900: Fundamentals of Sensor Design
Lecture 14Sensors and Digital Signal Processing (DSP)
Part 2: DSP Algorithms
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
DSP: Basic Modules
Digital Signal Processing Algorithms
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Digital Signal Processing Application and Algorithms
DSP Algorithms and their usage
Ref: Applied Digital Signal Processing: Theory and Practice, by D. Manolakis and V. K. Ingle
Application DSP Algorithm
Audio/Speech ProcessingCompression/Decompression, equalization, mixing, sound
synthesis, noise cancellation, stereo and surround sound
Image/Video Processingcompression/decompression, enhancement, video coding,
motion detection, image reconstruction
Transmission of audio,
video, data
modulation/demodulation, error correction coding,
encryption/decryption, echo cancelation, multipath
equalization, cellular networking algorithms
Military/Tactical Systemsnavigation, beamforming, radar and sonar processing,
software defined radio
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Image Compression and Decompression
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Audio Compression and Decompression
Differential Pulse Code Modulation (DPCM)
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Image Reconstruction
Dr. Larry Zeng's Research (Filtered Backprojection Algorithm)
Airport Bag Scans
Low Dosage Clinical CT
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Modulation/Demodulation
Communications (FSK, BPSK, QPSK, etc..)
Binary Phase Shift Keying (BPSK)
1) Phase of the carrier changes depeneding on the data, e.g. 0 deg for 1 and 180 deg for 0
2) Robust to noise, BPSK is coherent as the phase transitions occur at the zero crossing
pointsOut of phase
component Q (sine)
In-phase
component I (cosine)
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
BPSK Modulation/Demodulation
Modulation
Demodulation Low Pass Filter
BPSK Signal
Matlab Central: BPSK modulator http://www.mathworks.com/matlabcentral/fileexchange/12691-bpsk-modulation
BPSK Demodulator http://www.mathworks.com/matlabcentral/fileexchange/25243-bpsk-demodulator
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Filtering
Filters are signal conditioners
Filters are signal conditioners
Filter by accepts an input signal, blocks prespecified frequency
components, and passes the original signal minus those components
to the output
Types of Filters
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
Filtering
Low Pass Filter Types
Four major types (IIR): Butterworth, Chebyshev, Elliptic, Bessel
Filter phase response is important. Why?
Amplitude Response Phase Response
Check in Matlab
(type fdatool )
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
IIR Filter
Infinite Impulse Response (IIR) Filter1) Feedback, recursive: current output depends on previous outputs
2) Implemented by using a series of delays, multipliers, and adders
Tap
X
+
Delay
bM
xn
Xb2
+
Delay
Xb1...
+
Delay
Xb0
yn
Numerator
Coefficients
01100110 ...... xbxbxbyayaya MnnMnn
M-1 delays
Filter Order= M
X
+
Delay
-aMX-a2
+
Delay
X-a1
+
Delay
X-a0
Denominator
Coefficients
...
+
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
FIR Filter
Finite Impulse Response (FIR) Filter
1) No feedback
2) Implemented by using a series of delays, multipliers, and adders
Tap
X
+
Delay
bM
xn
Xb2
+
Delay
Xb1...
+
Delay
Xb0
yn
Numerator
Coefficients
0110 ... xbxbxby Mnnn
M-1 delays
Filter Order= M
b0xn
b1xn-1b2xn-2bMx0
Note: 1) Delay =1 clock delay in DSP FPGA/Microprocessor
2) Tap is implemented by Multiply-accumulator (MAC) unit in DSP
Microprocessor
Design an FIR Filter in Matlab
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ECE 5900/6900 Fundamentals of Sensor Design Dr. Suketu Naik
FIR Filter Implementation
Finite Impulse Response (FIR) Filter (more common)
Implement an FIR Filter in Microprocessor
Arduino
http://www.arduinoos.com/2011/07/fir-filters-part-1/
Spartan3
http://www.xilinx.com/products/intellectual-property/fir_compiler.html#overview
Raspberry PI
https://volumio.org/forum/dsp-with-raspberry-hifiberry-and-volumio-drc-folve-t672.html
SiLabs C8051F020DK MCU Kit
?
Microchip PIC18 Microcontroller
http://ww1.microchip.com/downloads/en/AppNotes/00852a.pdf