From Analog to Software Defined: A History of the Radio

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From Analog to Software DefinedA History of
the Radio

• Roland Kempter
• kempter_at_ece.utah.edu

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Organization

• The History of Radio Communication (incomplete)
• Important Concepts Filtering and Modulation
• Background Fourier Series Expansion
• SIMULINK Demo
• From Analog to Digital Software Defined Radio
• Programming Software Defined Radios

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History of the Radio James C. Maxwell
1861-1865 James Clerk Maxwell experiments with
electromagnetic waves 1873 describes the
propagation of electromagnetic waves in his
paper A Dynamical Theory of the
Electromagnetic Field
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Wireless Radio Begins Nikola Tesla
1893 Tesla gives public demonstration of
wireless radio communication at St. Louis,
Missouri. He describes in detail the principles
of radio communication.
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Wireless Radio Begins Guglielmo Marconi and K.
F. Braun
1896 G. Marconi is awarded a patent for
radio Improvements in Transmitting Electrical
Impulses and Signals and in Apparatus There-for
1897 Marconi establishes a radio station on the
Isle of Wight (England)
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The History of the Radio
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Better Sound Quality FM Radio
1933 Edwin H. Armstrong patents FM radio
(better quality than AM) 1940s analog
television transmissions start in North America
and Europe.
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The History of the Radio the 21st century
Internet radio Streaming Internet connection, no
RF, IF, etc. Digital Audio Broadcasting
(DAB) alternative to FM Satellite Radio XM
Radio, Sirius Satellite Radio etc
Going from analog payload to digital payload
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The Fundamental Blocks in a Radio
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The Theory Behind Radio Technology Fourier Series
Jean Baptiste Joseph Fourier (1768-1830) French
mathematician and physicist Idea any periodic
function can be decomposed into an (infinite)
sum of sines and cosines Fourier applied it to
to problems of heat flow.
1824 gases in the atmosphere increase the
surface temperature of the Earth. Fourier
described the greenhouse effect!
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The Theory Behind Radio Technology Fourier Series
Fourier Series describes the frequency content of
periodic signals
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Example Square Pulse, infinite harmonics!
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Example Sawtooth Wave
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Example Triangle Wave
Rect-wave poor TD quality with 25
harmonics Sawtooth-wave poor TD quality with 25
harmonics Triangle-wave pretty good TD quality
with 10 harmonics
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Example Fourier Transform
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What is Modulation
Modulation multiplication of baseband signal by
a carrier wave
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Fundamental Blocks Why is Modulation Necessary?
At least 2 reasons

• different signals from different systems do not
  interfere
• Example - broad band cable services
• - Public TV and Radio (wireless services)

• move the payload signal to frequency where it can
  be
• transmitted most easily
• Problem - signal attenuation in wires
• - free space signal attenuation

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What is Filtering?
Input Signal
Filter Response
Output Signal
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Modulation and Demodulation
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Fourier Series Continuous and Discrete
Nice, but all of this was for continuous
signals, What about discrete (digital) samples?
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SIMULINK DEMO BPSK Radio
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A Radio?
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A Conventional Radio all in Analog
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New Paradigm Software Defined Radio (SDR)
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A Radio!
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SDR is Real!
23 November 2004 FCC approves the first SDR
device in the United States. If radio changes
behavior, no more re-approval necessary!
VANU Inc., ANYWAVE cellular base station HP
proliant server, ADC/DAC, running Linux, can act
as a GSM, CDMA and UMTS basestation through
software updates
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Programming Software Defined Radios Download?
Trinity Operator, I need a pilot program for a
V-212 helicopter!
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Programming Software Defined Radios Now and
Future
Classical way VERILOG Problem hardware
(board) specific, rewrite for different boards
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SDR with Ontology Language
SDR to Operator Ive been an AM radio all my
life, I want to become an FM radio!
Operator Youll need to reconfigure your
demodulator. SDR How do I do that? Operator Yo
u need 15 multipliers and 20 adders, do you have
that? SDR Yes. Operator Now connect.
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About us SDR at the Wireless Communications Lab
Now
2 Laptops running the GNU radio software,
modified to work as 4 by 4 MIMO system, progam
PHY In January upgrade to 3 boards that feature
VIRTEX 4 ARM 9 DSP, running real-time OS,
program PHY, MAC and Network layers
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Why all that?
WE WANT YOU FOR SOFTWARE DEFINED RADIO