NI @ ECE.UTAustin.Edu
http://www.ece.utexas.edu
http://www.wncg.org
Prof. Brian L. Evans
Dept. of Electrical and Computer Engineering
The University of Texas at Austin, Austin, Texas USA
bevans@ece.utexas.edu
Contributions by Profs. Francis Bostick, Bruce Buckman, Robert Heath, Archie Holmes, Jon Valvano.
Additional contributions by Vishal Monga, Zukang Shen, Ahmet Toker, and Ian Wong, also UT Austin.
Outline
• Introduction
• Real-Time Digital Signal Processing (DSP) Lab Course
http://www.ece.utexas.edu/~bevans/courses/realtime/
• Wireless Communications Lab Course (Prof. Robert Heath)
http://www.ece.utexas.edu/~rheath/courses/wirelesslab/index.php
• Prototyping Ad-Hoc Networks (Prof. Robert Heath)
• Conclusion
Introduction
• ECE Department at UT Austin
– 62 tenured and tenure-track faculty (expanding to 75) 10 ECE faculty
positions open
– 1500 undergraduate and 600 graduate students
• LabVIEW license for ECE predates 1996
– May be installed on any ECE machine or any ECE student machine
• Use of NI products in ECE courses predates 1996
– Required junior-level electronics lab course
– LabVIEW coupled with NI data acquisition system to
measure time and frequency responses of devices
Introduction
• The Wild West of course numbering at UT Austin
– First digit indicates the number of credits
– Middle digit of 0 means first-year undergraduate course
– Middle digit of 1 means second-year undergraduate course
– Middle digit of 2-7 means upper division course
– Middle digit of 8-9 means graduate course
– I just work here …
• EE 302 Introduction to Electrical Engineering
– Required for first-year first-semester ECE students
– Use NI ELVIS workstation for all analog circuits labs
– Saves significant amount of lab space
Prof. Archie
Holmes
EE 438 Electronics I – Lecture Component
• Junior-level required course for both majors
• In-class demonstrations using NI ELVIS
– Demonstrate performance of a variety of electronic circuits
– Project ELVS board using a document camera
– Switch to simulated measuring instruments to analyze performance
• In-class demonstrations using NI Electronics Workbench
– Often coupled with ELVIS demonstration
• Similar approach for EE 338K Electronics II
– Junior-level elective for both majors
Prof. Francis
Bostick
EE 438 Electronics I – Lab Component
• Objectives of junior-level required course for both majors
– Make time- & frequency-domain measurements on electronic circuits
– Utilize measurements with predictions from circuit simulation software
(like PSPICE or MultiSIM) to troubleshoot circuits
• Automated stimulus/response measurements
– Diode rectifiers and amplifiers based on MOSFETs & BJTs
– Using NI digital acquisition hardware controlled by
Prof. Bruce
Buckman
suite of LabVIEW Express VIs developed for course
• Entire lab content delivered to students via the Web
http://www.ece.utexas.edu/~buckman
EE 362K Intro to Auto. Control
• Required senior-level course for BSEE majors
– Uses LabVIEW to design feedback control systems
• System identification of system to be controlled
– Students interactively add/delete poles/zeros from a transfer function
until it agrees with time and frequency measurements of the plant
• Analog controller design to tailor closed-loop system
– Students interactively add/delete poles/zeros in controller to achieve
target closed-loop system performance in time and frequency
• Digital controller design for implementation
– Students interactively modify controller to fix problems
as sampling frequency lowered toward realistic final value
Prof. Bruce
Buckman
EE 464 Senior Design Project
• Required senior-level course for all majors
– Students work individually or in teams of two
• Sample projects using LabVIEW
– Shaun Dubuque and Richard Lam, “Vital Signs Monitor”
– Steven Geymer and Matt Dione, “Infrared Eye Tracking
System with Distributed Control”
– Stephen Pun, "Discrete Multitone Modulation Modem Testbed“
– Altamash Janjua and Umar Chohan, "OFDM Transmitter Based on the
Upcoming IEEE 802.16d Standard“
http://www.ece.utexas.edu/~bevans/courses/ee464/AltamashJanjua/finalreport.htm
– Abdelaziz Skiredj, "Quantifying Tradeoffs in Adaptive Modulation
Methods for IEEE 802.16a Wireless Communication Systems"
Selected Graduate Courses
• EE 382C-9 Embedded Software Systems
Prof.
Brian
Evans
– System-level modeling and simulation (breadth)
– Dataflow modeling, scheduling, and synthesis (depth)
– LabVIEW is homogeneous dynamically-scheduled dataflow model
http://www.ece.utexas.edu/~bevans/courses/ee382c
• EE 385J-17 Biomedical Instrumentation II
Prof.
Jonathan
Valvano
– Lab 1. Analog/Digital Noise Analysis w/ LabVIEW
– Lab 2. Heart Sounds w/ LabVIEW
– Lab 5. Embedded System Project (LabVIEW or 9S12C32)
http://www.ece.utexas.edu/~valvano/BME385Jinfo.html
Real-Time DSP Course: Overview
• Objectives of undergraduate elective class
– Build intuition for signal processing concepts
– Explore signal quality vs. complexity tradeoffs in design
– Translate DSP concepts into real-time software
Over 600
served
since 1997
• Lecture: breadth (three hours/week)
• Laboratory: depth (three hours/week)
– Deliver voiceband transceiver using TI DSP processors/tools
– Test/validate implementation using NI LabVIEW and rack equipment
• “Design is the science of tradeoffs” (Prof. Yale Patt, UT)
Real-Time DSP Course: Show Me The Money
– 400 Million units/year: automobiles, PCs, cell phones
– 30 Million units/year: ADSL modems and printers
Consumer Electronics
Product
Wireless phone
Digital cameras
Portable CD players
MP3 players
Compact audio systems
Average
Unit Price
$136
$271
$ 48
$137
$111
Annual
Revenue
$11.5 Billion
$ 4.2 Billion
$ 0.9 Billion
$ 0.7 Billion
$ 0.5 Billion
• How much should an embedded processor cost?
Source: CEA Market Reseach.
Data for 2004 calendar year.
• Embedded system demand: volume, volume, …
Real-Time DSP Course: Which Processor?
• How many digital signal processors are in a PC?
• Digital signal processor worldwide revenue
– $6.1B ‘00, $4.5B ‘01, $4.9B ‘02, $6.1B ‘03, $8.0B ‘04
– Estimated annual growth of 23% until 2008
– 43% TI, 14% Freescale, 14% Agere, 9% Analog Dev (‘02)
• Fixed-point DSPs for high-volume products
– More than 90% of digital signal processors sold are fixed-point
– Floating–point DSPs used for initial real-time fixed-point prototype
– Floating-point DSP resurgence in professional and car audio products
• Program floating-point TI TMS320C6700 DSP in C
Revenue figures from Forward Concepts (http://www.fwdconcepts.com)
Real-Time DSP Course: Textbooks
• C. R. Johnson, Jr., and W. A. Sethares,
Telecommunication Breakdown, PH, 2004
– “Just the facts” about single-carrier transceiver design
– Matlab examples
– CD supplement featuring Rick Johnson on drums
• S. A. Tretter, Comm. System Design using DSP
Algorithms with Lab Experiments for the
TMS320C6701 & TMS320C6711, Kluwer, 2003
– Assumes DSP theory and algorithms
– Assumes access to C6000 reference manuals
– Errata/code: http://www.ece.umd.edu/~tretter
Bill Sethares
(Wisconsin)
Steven Tretter
(Maryland)
Real-Time DSP Course: Where’s Rick?
Rick Johnson
(Cornell)
Real-Time DSP Course: QAM Transmitter
Lab 4 Rate
Control
LabVIEW reference design/demo by Zukang Shen (UT Austin)
Lab 6
QAM
Encoder
Lab 2
Passband
Signal
Lab 3
Tx Filters
http://www.ece.utexas.edu/~bevans/courses/realtime/demonstration
Real-Time DSP Course: QAM Transmitter
Control
panel
QAM
passband
signal
Eye
diagram
LabVIEW demo by Zukang Shen (UT Austin)
Real-Time DSP Course: QAM Transmitter
square root raised cosine, roll-off = 0.75, SNR = 
raised cosine, roll-off = 1, SNR = 30 dB
passband signal, 1200 bps mode
passband signal, 2400 bps mode
Real-Time DSP Course: Lab 2. Sine Wave Gen
• Ways to generate sinusoids on chip
– Function call
– Lookup table
– Difference equation
• Ways to send data off chip
– Polling data transmit register
– Software interrupts
– Direct memory access (DMA) transfers
• Expected outcomes are to understand
– Signal quality vs. implementation complexity tradeoffs
– Interrupt mechanisms, DMA transfers, and codec operation
Real-Time DSP Course: Lab 2. Sine Wave Gen
•
Evaluation procedure
–
–
–
–
Validate sine wave frequency on scope
Test subset of 14 sampling rates on board
Method 1 with interrupt priorities
Method 1 with different DMA initialization(s)
New School
Old School
C6701
DSP
HP 60 MHz
Digital Storage
Oscilloscope
LabVIEW DSP
Test Integration
Toolkit 2.0
Code Composer
Studio 2.2
Real-Time DSP Course: Lab 3. Digital Filters
• Implement digital linear time-invariant filters
– FIR filter: convolution in C and assembly
– IIR Filter: direct form and cascade of biquads, both in C
• Expected outcomes are to understand
– Speedups from convolution assembly routine vs. C
– Quantization effects on IIR filter stability
x[k]

– FIR vs. IIR: how to decide which one to use
• Filter design gotcha: polynomial inflation
– Polynomial deflation (rooting) reliable in floating-point
– Polynomial inflation (expansion) may degrade roots
– Keep native form computed by filter design algorithm
y[k]
1/2
1/8
Unit
Delay
y[k-1]
Unit
Delay
y[k-2]
Real-Time DSP Course: Lab 3. Digital Filters
• IIR filter design for implementation
– Butterworth/Chebyshev filters special cases of elliptic
– Minimum order not always most efficient
– In classical designs, poles sensitive to perturbation
– Quality factor measures sensitivity of pole pair to oscillation:
Q  [ ½ ,  ) where Q = ½ dampens and Q =  oscillates
Q
poles
zeros
Q
poles
zeros
1.7
-5.3533±j16.9547
0.0±j20.2479
0.68
-11.4343±j10.5092
-3.4232±j28.6856
61.0
-0.1636±j19.9899
0.0±j28.0184
10.00
-1.0926±j21.8241
-1.2725±j35.5476
optimized
classical
• Elliptic analog lowpass IIR filter example [Evans 1999]
Real-Time DSP Course: Lab 3. Digital Filters
• Evaluation procedure
– Sweep filters with sinusoids to construct magnitude/phase responses
• Manually using test equipment, or
• Automatically by LabVIEW DSP Test Integration Toolkit
– Validate cut-off frequency, roll-off factor…
– FIR: Compare execution times
• C without compiler optimizations
• C with compiler optimizations
• C callable assembly language routine
– IIR: Compute execution times
• Labs 4-7 not described for sake of time
Test Equipment
Agilent Function
Generator
HP 60 MHz Digital
Storage Oscilloscope
Spectrum Analyzer
Wireless Comm. Lab: Overview
• A typical digital communication system
Physical
world
Transmitter
Source
Source
Coding
Channel
Coding
Modulation
Analog
Processing
Channel
Sink
Source
Decoding
Channel
Decoding
Demodulation
Propagation
Medium
Analog
Processing
Receiver
Digital
Analog
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Wireless Comm. Lab: A DSP Approach
• Decompose block diagram into functional units
Inputs
System
0110110
h[n]
Outputs
0110110
h(t)
time
time
QuickTi me™ and a
T IFF (Uncom pressed) decom pressor
are needed to see t his pict ure.
time
time
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Wireless Comm. Lab: Premises
• Learning analog communication e.g. AM/FM are no
longer essential (think vacuum tubes)
• A digital communication system can be abstracted
as a discrete-time system
• Concepts from signals and systems can be used to
understand the complete wireless system
• Experimental approach to wireless builds intuition
on system design
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Wireless Comm. Lab: Course Topics
• DSP models for communication systems
– Sampling, up/downconversion, baseband vs. passband
– Power spectrum, bandwidth, and pulse-shaping
Initial offering
• Basics of digital communication
in Spring 2005
– QAM modulation and demodulation
– Maximum likelihood (ML) detection
• Dealing with impairments
– Channel modeling, estimation and equalization
– Sample timing, carrier frequency offset estimation
– Orthogonal frequency division multiplexing (OFDM)
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Wireless Comm. Lab: One Lab Station
Transmitter
PXI-5421
Source
Channel
Coding
Modulation
D/A
PXI-5610
RF Up
Channel
Sink
Decoding
Dell PC with LabVIEW software
Demod
A/D
RF Down
PXI-5620
PXI-5600
SMA
MXI-3
PXI Chassis
Receiver
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Wireless Comm. Lab: One Lab Station
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Prototyping Ad Hoc Networks: Introduction
• Ad hoc networks are loose collections of nodes
– Important for military applications
– Applications to in-home networking
• Prototyping requires physical & network software
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Prototyping Ad Hoc Networks: Description
• Radio
– RF transceiver uses TI IEEE 802.11a/b/g radio
– ADC / DAC using NI 5620 and NI 5421
MIMO-OFDM Ad Hoc
Network Prototype
• Physical layer
– In LabVIEW on embedded PC in PXI chassis Profs. Robert W. Heath, Jr.,
• PHY / MAC interface
– Gigabit Ethernet
• Medium access control
– Implemented in Linux on dedicated PC
Scott Nettles (UT Austin)
and Kapil Dandekar (Drexel)
Funding from NSF and NI
Equipment donations from
Intel, NI, and TI
• Networking (packet routing, etc.)
– Implemented using Click Modular Router (C++)
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Prototyping Ad Hoc Networks: Node Diagram
RF Front-end
(TI)
RF Front-end
(TI)
AD
DA
CC
NN
I I
55
64
22
01
MIMO/OFDM
Send
PHY
Cntrl
Gigabit
Ethernet
PXI 8231
MIMO Ad-Hoc
MAC Net
App
MIMO/OFDM
Recv
PXI 8187 Controller
LabVIEW
Click Modular
Router (C++)
NI 5620 64Mb buffer
NI 5421 256Mb buffer
NI PXI CHASSIS
Dell X86 Linux Host
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu
Prototyping Ad Hoc Networks: Two Nodes
Slide by Prof. Robert W. Heath, Jr., UT Austin, rheath@ece.utexas.edu