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USING SDR FOR HANDS-ON DIGITAL COMMUNICATION SYSTEMS ENGINEERING EDUCATION
Alexander M. Wyglinski, Di Pu, Daniel CullenWorcester Polytechnic Institute, Worcester, MA, USA
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Acknowledgements
We would like to express our sincere gratitude to The Mathworks for their financial and technical support during the development of the SDR-based undergraduate digital communications course
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Motivation
Software-defined radio represents a significant paradigm shift in how data transmission is performed SDR rapidly becoming prevalent technology in
commercial, defense, and public communication sectors Although fundamental concepts in digital
communications and digital signal processing are unchanged, algorithm implementation on SDR platforms revolutionary
Interdisciplinary Computer engineering
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
What is SDR?
Figure 1: The structure of a typical software defined radio communication system.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
USRP2 Platform
Figure 2: Front panel of a Universal Software Radio Peripheral, Version 2 (USRP2) SDR platform.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
GNU Radio & GRC
Figure 3: Screen capture of the GNU Radio Companion software employed in a digital communications experiment using the USRP2 as an actual wireless receiver.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Simulink USRP2 Interface (1)
Figure 4: Properties window for the Simulink USRP2 transmitter interface block.
Figure 5: Properties window for the Simulink USRP2 receiver interface block.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Simulink USRP2 Interface (2)
Figure 6: Sample Simulink implementation of a DBPSK transmitter employed in Laboratory 1 of the digital communications course. Notice the use of the Simulink USRP2 transmitter interface block.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Course Format & Evaluation
WPI undergraduate course format 7-week terms Lecture: MTRF 1:00 PM – 1:50 PM Supervised Laboratory: W 2:00 PM – 4:50 PM
Evaluation No class tests of final exams Course entirely project driven (team size = 2 students) Pre-lab, lab demo, lab report, course design project
Significant amounts of contact hours between instructor/teaching assistant and students
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Linkage Between Theory & Practice
Topics covered over the duration of this course, each via a laboratory experiment: Digital Signaling and Data Transmission Error Performance of Digital Communications in Noise Receiver Structures Spectrum Sensing and Identification
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Project Driven Learning
Figure 7: Photograph of a supervised laboratory session for the proposed digital communication systems course. Note the availability of a USRP2 platform at each lab workstation.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
“Getting Started” Phase
MATLAB Refresher and Simulink Introduction USRP2 Hardware Experimental Preparations Interaction between Simulink and USRP2 Hardware
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Open-Ended Design Component
In addition to some guided experimentation and laboratory work, every laboratory assignment possessed an open-ended design component to synthesize concepts Four open-ended design components
Automatic Frequency Offset Compensator Frame Synchronization Duplex Communication Carrier sense multiple access with collision avoidance (CSMA/CA)
Students found this to be the best part of each experiment Open-ended design components chosen to prepare students
for course design project
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Course Design Project (1)
Design and implement a software-defined radio (SDR) communication system capable of performing ad hoc wireless networking Project synthesizes open ended design components from
each laboratory experiments Students progressively build up their final prototype
The prototype SDR communication system must be able to either join an existing ad hoc wireless network or establish an ad hoc wireless network of its own when no such network is present
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Course Design Project (2)
Progressive monitoring and evaluation of student course design project activities Design Proposal: 5% Due at end of Week 2
Mid-term Progress Review: 5% During Week 4
Final In-Class Demonstration: 10% During Week 7
Final Project Report: 10%
Total Grade: 30%
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Course Design Project (3)
Figure 8: Example of the final prototype for the course design project.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Real-World Experience (1)
Figure 9: Experimental results using correlation of incoming signal (Barker sequence embedded) showing change in sampling delay.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Real-World Experience (2)
Significant design decisions encountered during course Trade-offs between computational complexity and
system functionality performance SDR prototypes heavily dependent on computational
horsepower of available processing resources
Understanding resource constraints became apparent throughout course “358” frame size Decimation rate of 512
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Student Feedback is Essential!
Figure 10: For each laboratory, there is a online survey to collect the feedback from students.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Feedback Summary (1)
Q1: Difficulty level of this lab. Too Easy = 0
Easy = 0
Reasonable = 9
Difficult = 18
Too Difficult = 4
Q2: Which aspects of this lab did you find interesting? Theoretical Prep = 0
MATLAB Simulations = 8
Simulink Simulations = 7
Simulink SDR Experimentation = 12
Open-Ended Design Problem = 24
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Feedback Summary (2)
Q3: Which aspects of this lab do you think need to be improved? Theoretical Prep = 9
MATLAB Simulations = 4 Simulink Simulations = 9 Simulink SDR Experimentation = 10
Open-Ended Design Problem = 6
Q4: What modifications and/or additions would you suggest for future offerings of this lab? Better linkage between pre-labs (math!!) and experiments
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Feedback Summary (3)
Q5: How did you find the Simulink software employed in this lab? Unsatisfactory = 0
Needs Improvement = 14
Reasonable = 8
Good = 9
Excellent = 0
Q6: How did you find the clarity and level of detail for this lab handout? Very Poor = 0
Poor = 2
Reasonble = 12
Good = 13
Excellent = 4
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Feedback Summary (4)
Q7: What was your level of interest regarding the experiments conducted in this lab? Very Low = 0
Low = 0
Indifferent = 6
High = 21
Very High = 4
Q8: What was the level of reliability and accessibility of the lab hardware and computer workstations? Very Low = 1
Low = 8
Reasonable = 10
High = 9
Very High = 2
Q9: Any other comments? Why Linux? Better computers needed!! More SDR platforms available for the lab (14 radios for 10 lab
teams!!)
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Next-Generation USRP Hardware
Figure 12: The USRP E100 software defined radio is an embedded stand-alone system.
Figure 11: The USRP N210 software defined radio builds on the USRP2 platform, offering higher performance and increased flexibility.
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Using SDR for Hands-On Digital Communication Systems Engineering Education
UHD Interface
Universal Hardware Driver Current Simulink interface uses User Datagram
Protocol (UDP) UDP requires packet length = 358 UHD will enable a flexible packet length
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Using SDR for Hands-On Digital Communication Systems Engineering Education
SDR Textbook to be Published
An SDR textbook based on this course and using Simulink expected to be published in 2012
Tentatively consists of the following chapters: Signals and Systems
Random Variables and Processes
Digital Modulation and Demodulation
Receiver Structure & Waveform Synthesis
Synchronization
Equalization
Multicarrier Modulation
Spectrum Sensing Techniques
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Using SDR for Hands-On Digital Communication Systems Engineering Education
Presentation Overview
Motivation What is SDR? Different SDR Experimentation Tools ECE4305 “SDR Systems and Analysis” Next Steps More Information
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Using SDR for Hands-On Digital Communication Systems Engineering Education
For More Information
Professor Alexander WyglinskiDepartment of Electrical and Computer Engineering
Worcester Polytechnic InstituteAtwater Kent Laboratories, Room AK230
http://www.wireless.wpi.edu/
Thank You!