senior design projects using software designed radio (sdr)skatz/katzpage/sdr_project/sdr/sdr... ·...
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P R O F . S H A R L E N E K A T Z P R O F . J A M E S F L Y N N
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Senior Design Projects Using Software Designed Radio (SDR)
Overview
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Traditional hardware radio versus Software Defined Radio
What is SDR? Advantages and applications of SDR Group projects Schedule for Winter/Spring
Traditional Transceiver (Hardware)
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• Amplifiers • Modulators • Demodulators • Mixers • Filters • Oscillators
Disadvantages of the Traditional Hardware Receiver
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Simple modulation / demodulation only Limited implementation of filters Alignment Aging Complexity Fixed design: frequency/mode Non linearity – unwanted signals These are limitations of a hardware based system
What is Software Defined Radio (SDR)?
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• A new technology for implementing radio
communications systems
• Art and science of building radios using primarily
software
• Eliminating hardware and moving software as close to the
antenna as possible
• Future direction of communications systems
• Encompasses many areas of EE: communications, signal
processing, antennas, RF, digital design, software
Traditional Hardware Receiver
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RF Amplifier
IF Amplifier x
Demod- ulator
Local Oscillator
Receiver Front End
Traditional / Hardware Receiver
Shifts spectrum down to lower
frequency
Hardware: Envelope detector, slope detector, etc.
Software Defined Radio
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SoftwareAnalog to
DigitalConverter
Radio is modified by changing the
software. The hardware remains
the same
Advantages of SDR
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Makes communications systems reconfigurable (adapting to new standards)
Flexibility (universal platform – not special purpose) – Hardware stays the same
Upgradable, modifiable Filters/other hardware Cognitive/Smart Radio
SDR Applications
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Military
Radio Astronomy
Amateur Radio
Future Personal Communications
Cell phones Wi Fi Entertainment distribution
Public Safety Broadcasting
Digital Radio
Digital Television
Components of a SDR System
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ADC
FPGA (Decimator, MUX, etc.)
USB Controller PC
Daughterboard (optional) Motherboard
Shifts the frequency of the desired
signal
Samples the
analog signal
Performs initial signal processing
Software for Transmitter/
Receiver
For development purposes
USRP - Motherboard/Daughterboard
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GNU Radio Software
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Community-based project started in 1998 GNU Radio application consists of sources (inputs),
sinks (outputs) and transform blocks Transform blocks: math, filtering, modulation/
demodulation, coding, etc. Sources: USRP, audio, file input, signal generator, … Sinks: USRP, audio, file output, FFT, oscilloscope, … Blocks written in C++ Python scripts used to connect blocks and form
application
SDR Demonstration
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AM Receiver
System can be changed to FM, SSB, Digital Modulation, etc. by just changing the software.
Group Projects for Spring 2009
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Unmanned Air Vehicle (UAV) Telemetry Link Two way communications link between a ground station and a
UAV Used to send location information and images
General Purpose Transceiver Multi-mode: AM/FM/ SSB/Digital, Voice/Data/CW Wide frequency spectrum: HF, VHF, UHF, + Signal processing
Groups will work together
Schedule
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Winter Break Lectures on SDR (for new group members) Introduction to digital communications (everyone) Developing a work plan for the year
Spring Semester Regular working meetings Work plan
Winter Meeting times
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Questions?