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A Short History of Radio
fred harris
22-July 2011
IEEE Distinguished Lecturer
IEEE Fellow & Life Member
It appears to
be a new wireless
technology
What’s A Super Hero to do?
Where have all
the Phone Booths
Gone?
What The Customer Wants
What The Customer Expects to Pay
MO R EMO R E
MO R EMO R E
MO R E MO R E MO R E MO RE MO R E
MO RE
MO R E
MORE MORE MORE MORE
MORE
MORE MORE MORE
MORE MORE
MORE MORE MORE MORE
MORE MORE MORE MORE
MORE MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
M MO
O
R
RE
E
MORE
MORE
MORE
S LESSS LESSS EVEN
LESS
When The Customer Wants it
MO R EMO R E
MO R EMO R E
MO R E MO RE MO R E MO RE MO R E
MO RE
MO R E
MORE MORE MORE MORE
MORE
MORE MORE MORE
MORE MORE
MORE MORE MORE MORE
MORE MORE MORE MORE
MORE MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
MORE
M MO
O
R
RE
E
MORE
MORE
MORE
NEXTWEEKTOMORROW THISAFTERNOON
What Size Customer Wants
We have a better appreciation of where we are
when we remember from where we started
and how far we have come.
Very Early Communications at a Distance:
Free Space Acoustic and Optical Channels
Drums, Whistles,Cannon Fire
Claude Chappe 1793Optical Telegraph
Smoke Signals, Semaphore, Beacon Fires, Ship Flags, Heliograph, Signal (Aldis) Lamp
GSM,CDMA, SDR
digital signal processing, DR
audio broadcast
Marconi's experiments
Hertz's experiments
Maxwell equations
1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 2030
Shannon, television
transistor
CDMA-2000, WLAN, CR
Mrs. Harris’s First Born
A Time Line
Milestones in Electromagnetic Communications
Hans Christian Oersted, 1777-1841, Current-Magnetic Field 1820
Michael Faraday, 1791-1867, Induction 1831
J.C. Maxwell, 1831-1879,
“Treatise on Electricity and Magnetism”, 1873
H.L. Helmholtz, 1821-1894 Predicted E-M Waves
Heinrich Hertz, 1857-1894 Radio Propagation, 1887
Alexander Popov, 1859-1905, Radio Day, 7-May 1895
Guglielmo Marconi, 1874-1937, Wireless Open Sea, 13-May 1897
Valdemar Poulsen, 1869-1942, Continuous Radio Waves, 1905
Lee de Forest, 1873-1961, Audion (Triode Valve), 1907
Edward Armstrong, 1890-1954, Regenerative 1914, Super Heterodyne 1917, Frequency Modulation, 1934
(25 April 1874 – 20 July 1937)
The inventor of radio Guglielmo Marconi on the 1995 German,
Italian, San Marino, Vatican, and Ireland Stamps.
Sent Wireless signals Across English Channel in 1899,
Received letter “S” (. . .) sent from Newfoundland to England 1901
World Wide Recognition
More World Wide Recognition
The inventor of radio Alexander Popov on the 1989 USSR stamp.
In 1900 a radio station was established under Popov's instructions on Hogland island
(16 March 1859 – 3 December 1906)
The inventor of radio Reginald Fessenden on the 2000 Canada stamp.
Christmas Eve and New Year’s 1906 Fessenden Broadcast short speech and Handel’s
Largo and a violin solo of O, Holy Night from a radio station at Brant Rock, Mass.
(6 October 1866 – 22 July 1932)
(10 July 1856 – 7 January 1943)
The inventor of radio Nikola Tesla on the 2009 Croatia stamp.
Tesla’s 1900 Radio Patent was overturned in 1904 in favor of Marconi’s Radio Patent. In
1943, Shortly after his Death, the Supreme court upheld Tesla’s original patent and his
claim as first inventor of tunable Radio Receivers.
(30 November 1858 – 23 November 1937)
The inventor of radio Jagadish Chandra Bose on the 1958 India stamp.
Bose’s 1904 US Patent described Galena Crystal Detector for Demodulating
Continuous Wave Radio Signals. He is acknowledged as inventor of Mercury
Auto Coherer used in Marconi’s Wireless Receiver.
USA” Four American Inventors” 1983 Commemorative Stamp Set
SuitSat-I (also known as Mr. Smith,
Ivan Ivanovich, RadioSkaf, Radio
Sputnik, and AMSAT-OSCAR 54) is
a retired Russian Orlan Spacesuit
with a radio transmitter mounted on
its helmet. SuitSat-1 was deployed in
an ephemeral orbit around the Earth
on 3-February 2006. The idea for this
novel OSCAR satellite was first
formally discussed at an AMSAT
symposium in October 2004, although
the ARISS-Russia team is credited
with coming up with the idea as a
commemorative gesture for the 175th
anniversary of the Moscow State
Technical University.
Suitsat-1Launched from
International Space Station
I’m Sorry Dave,
I Can’t Do That
HAL,
I Want you to
open the Hatch
2001: A Space Odyssey
Disruptive Technology in Communications
The printing press: 1450, German Inventor Johannes Gutenberg...
The Telephone: 1867,British Inventor Alexander Graham Bell
The Microprocessor: 1971American Inventor Ted Hoff...
Wireless (Radio): 1901,Italian Inventor Guglielmo Marconi
Disruptive Technology
The electric telegraph arrived in the early19-th century and redefined communications at a distance.
It required the confluence of three factors: The science of electromagnetism, The ability to generate or store electricity The Industrial Revolution to build the
required infrastructure
Communication at a Distance with
Electricity and Magnetism
1831 Joseph Henry invents the first electric telegraph.
1843 Samuel Morse invents the first
long distance electric telegraph line.
1858 Cyrus Field’s Company Lays the
Transatlantic Cable.
1876 Alexander Graham Bell patents
the electric telephone.
1889 Almon Strowger patents the direct dial
telephone automatic telephone exchange.
Brunel’s Great Eastern
We Need Some Source Coding Here
A
A
B
B
C
C
D
D
7
7
8
8
9
9
36 Lines
Samuel Thomas von Sömmering’s (1808-10)
"Space Multiplexed" Electrochemical Telegraph
Cooke and Wheatstone Telegraph
A
1 0
9
8
7
6
3
2
4
5
B
E
H
M
R
I
F
N
S
K
G
O
T
V
L
D
P
Y
W
2 out of 5 Coding (5*4 = 20 )
Single Needle Telegraph
Variable Length Code
Cooke-Wheatstone Single Needle Telegraph (c 1850)
THE TELEPHONE1876 - Alexander Graham Bell invents the Telephone. He offers the patent to Western Union for $100,000.
The President of the Telegraph Company, appointed a committee to investigate the offer. The often quotedreport reads in part:
The Telephone purports to transmit the speaking voice over telegraph wires. We found that the voice is very weak and indistinct, and grows even weaker when long wires are used between the transmitter and receiver.
Technically, we do not see that this device will be ever capable of sending recognizable speech over a distance of several miles.
Bell wants to install a “telephone device" in every city. The idea is idiotic on the face of it.
“We do not recommend its purchase."
Early Telephone Instruments
Ericsson "Eiffel Tower" Telephone, 1885
11 digit Potbelly Dial CandlestickStrowger 1905
Dial CandlestickAutomatic Electric 1921
Footnote: Western Electric 1877: 5 PhonesEngineers were 1894: 250,000 Phones
Wrong! Very Wrong! 1906: 7,500,000 Phones
Communication at a Distance by
Electromagnetic Radiation
(Radio or Wireless)
1894 Guglielmo Marconi improves wireless telegraphy.
1902 Guglielmo Marconi transmits radio signals acrossthe Atlantic Ocean.
1914 First cross continental telephone call made.
1916 First radios with tuners different stations.
1930 First television broadcasts in the United States.
It all Started with…..
Heinrich Rudolph Hertz,1847-1894
Shocking!
1. Induction Coil Produces High Voltage
2. Spheres store charge. Spark Acts as a switch allowing oscillatory currents between spheres storing charge. Changing Current produces Electromagnetic Waves
3. Electromagnetic wavesinduce voltage in resonator,Producing small spark in spark gap.
Hertz's students were impressed, and wondered what use might be made of
this marvelous phenomenon. But Hertz thought his discoveries were no more
practical than Maxwell's.
"It's of no use whatsoever," he replied. "This is just an experiment that proves
Maestro Maxwell was right .“
"So, what next?" asked one of his students. Hertz shrugged.
"Nothing, I guess."
Early Wireless Communications
Mechanical Radio, Moving Parts
Spark Gap TransmitterPulsed RF
Recipe for Coherer:30 medium sized grains from a German 5-pfenning piece, twice as much filings from nickel wire,and a little silver dust. Heat mixture.Place in evacuated glass tube.
Compliments of Copenhagen
Post & Tele Museum
Guglielmo Marconi, 1874-1937
December 12 1901Spark Gap Transmitter
Spark Gap Wireless Transmitter(Damped Oscillations)
Marine Spark Transmitter
Radio Operators aboard Ship Were Called
SparkyBecause they Operated the
Spark Transmitter
The Eiffel Tower
The Eiffel Tower was built for an industrial exposition (1889) and the centenary of the French Revolution.
It created amazement and outrage. The previous world champion, America's Washington Monument was half the tower's height. The tower held the title for the world’s tallest structure till 1930, when it was surpassed by the Chrysler Building.
Eiffel could find no practical application for the tower!Parisians spoke seriously of tearing the tower down.
Then Eiffel discovered the 20th century's killer app for towers, Marconi's radio! The tower started broadcasting signals in 1904 and by 1908, the French military had installed a radio espionage nest, where they could eavesdrop on German and Austro-Hungarian stations.
Due to Marconi’s invention, the tower's future was secure.
324
Meters
Valdemar Poulsen, 1869-1942
Replace Sparks with an Arc
500 KW Poulsen Arc Transmitter
Wireless Communications, Later Model
Invented in 1902 by the Danish engineer Valdemar Poulsen, The arc transmitter, unlike the spark transmitter, generated continuous radio waves.
Edwin Armstrong, 1890-19541912 feedback (regenerative) receiver
Regenerative Receiver
A little Feedback Goes a Long Way
TRF: Tuned Radio Frequency Receiver
Bread Board
Superheterodyne Receiver
From Disclosure: June 3, 1918
Edwin Armstrong’s Superheterodyne Patent
The Wireless Telegraph is not Difficult to
Understand.
The ordinary Telegraph is like a very long cat.
You pull the tail in New York, and it meows in
Los Angeles.
The Wireless is the same, only without the cat.
Albert Einstein (1938)
Applications of Early Radio
1912 Sinking of
RMS Titanic
1913 International Convention
for Safety of Life at Sea:
Resultant Treaty Required
Shipboard Radio Stations to
Operate 24-Hour per day.
15-April 1912
Spark
Transmitters
and
Interference
Navy Concerned about Interference to Ship
Communications from Amateur Operators:1912
An Act to Regulate Radio Communications
13-August 1912. Required License to operate transmitter
and Limited Amateurs to 200 Meter Wavelength (1.5 MHz)
ARRL American Radio Relay League, February 1915
Emphasis Public Service to keep Government at Bay
Radio During the World War: (1914-1919)
Vacuum Tube Equipment Revolutionized Radio
All Amateur and Commercial Radio Activity
Ceased on 7-April 1917 when US entered War
Illegal for private citizens to posses a radio
Transmitter or Receiver.
US Navy Purchased Nearly All Commercial
Radio Companies to Avoid Foreign Control
Congress was unhappy with ownership of US
commercial stations.
US Navy Sponsored Radio Cartel
Compromise: New American Controlled Cartel
formed to acquire assets of commercial stations
and radio manufacturing industry:
Partners: AT&T 10.3%
General Electric 30.1%
Westinghouse 20.6%
United Fruit 4.1%
American Marconi 34.9%
Radio Corporation of America (RCA)
Application Evolution
Wireless Telegraphy:
Symmetrical Point to Point as was
Wired Telegraphy
Wireless Telephony:
Unsymmetrical Point to Multipoint
No Precedence!
Borrowed agriculture term!
Broadcasting (spreading of seeds)
Commercial Broadcasting David Sarnoff: RCA General Manager 1921 & VP 1922
RCA formed National Broadcasting Corporation (NBC) to
promote Radio (1926) and develop market to sell
Radios.
Columbia Broadcasting System (CBS) formed (1928) to
Compete with NBC.
NBC operated parallel Networks designated Red and
Blue.
FCC, Created in 1934, in a 6-year battle forced NBC to
divest one of its two Networks in 1943
Blue Network was sold in 1943 and in 1945 it became
The American Broadcasting Company (ABC)
Vacuum Tube Replacement
Solid State Amplifier
John Walter William
Bardeen Brattain Shockley1908-1991 1902-1987 1910-1989
1947
Noble Prize 1956
Integrated Circuits
Robert Noyce, Intel
Jack KilbyTI
1958
1923-2005 1928-1990
Noble Prize 2000 Noyce Founded IntelTed Hoff worked for Noyce
20102000199019801970196019501947
1,000
10,000
100,000
1,000,000
10,000,000
100,000,000
1,000,000,000
10,000,000,000
Transis
tors
per chip
8080 4,500
8088 29,000
286 134,000
386 275,000
486 1.2 Million
Pentium 3.1 Million
Pentium II
Celeron 7.5 Million
Pentium 4
Itanium
Xeon 42 Million
Itanium 2
Itanium2
8008 3,500
4004
First
processor
2,000
7.5 Million
5.5 MillionPentium Pro
42 Million
25 Million
220 Million
592 Million
1977
Apple II
1947
Transistor
Invented
1965
Gordon Moore
States his famous
axiom, later called
Moore’s law
1958
Jack Kilby (TI) &
Robert Noyce
(intel) Invent
Integrated
Circuit 1983
Motorola
First
Mobile Phone
1991
Kodak
First
Digital Camera
1996
DVD
Players
1999
BlackberryM
oore’s
Law: T
he densit
y of t
ransis
tors
on a c
hip d
oubles e
very
24 m
onths
More, More, MooreCritics have predicted the imminent
demise of Moore’s law ever sinceGordon Moore stated it in 1965.
Electrical Engineers continue to
defy physical challenges,
squeezing ever more
circuitry into less space
and making informationfly ever more
swiftly.
We all own a billion
Transistors
We have an amazing wealth of
resources at our disposal!
Just how big is a Billion?
A stack of a billion bank notes would be
76.2 kilometers High.
A billion seconds is 32.5 years!
For Comparison, the Eiffel Tower
Contains 18,084 Parts. It is
Fastened Together by 2.5 Million Rivets
The world manufactures more
transistors than it grows
grains of rice.
0.13-micron, Intel Pentium 4
300-mm silicon wafer.
Long Grain Jasmine Rice
Wow!
How big is a billion grains of rice?
8mm x 2mm x 2mm (Long Grain)
1-billion grains of rice
8 Meters x 2 Meters x 2 Meters
Or 32 Cubic Meters
Or a cube 3.2 Meters on a side
It weighs 24,000 kg (26.5 short tons USA)
It costs $13,000 (3-rd week Dec 2010)
CLS-350 Mercedes Benz weighs 2,200 kg
A Billion Transistors costs $20.0
0.00000001
Gordon_Moore_ISSCC-02-10-03
It’s all done with Computer Chips
Harry Nyquist, (1889-1960)
The Sampling Theorem
fS>BW
Analog-to-Digital Converter
A-to-D
ADC
Digital-to-Analog Converter
DAC
D-to-A
Evolution: Chapters 3 and 4
Positive Fdbk
DET
DET
AMP
AMPAMP AMP
ANT
ANT
TUNE
TUNE
TICKLER
TUNE TUNE
RF
RFRFRF
Evolution: Chapters 5 and 6
DETAMPAMP AMP
AMP
ANT
TUNE
IF IFRF
AMPAMP
AMPAMP
ANT
/2
BASE
BANDPROC
TUNE
RF IF
CARRIER
Please send along a Carrierso I can Demodulate
Never Mind, I’ll make my Own!
Start of the Modern era
ADC and DSP Insertion
Oh no! Another Oscillator!
Sample the
Intermediate Frequency StageDSP
Down Convert
Perform Timing and Carrier
Synchronization in DSP Land
Difference Between Working in
Analog Land and Digital Land
Analog Land is like working in
Minnesota in High Winter.
Snowing, Cold Air,
Harsh Biting Wind, no Sunshine.
Digital Land is like working in
San Diego in High Summer.
Gentle Breeze,
Surf’s up, Warm Sweet Air, Sunshine.
The Modern EraDigital Radio (DR): The baseband signal processing implemented on a DSP.
Software Radio (SR): An ideal SR samples at the antenna output.
Software Defined Radio (SDR): An SDR is a realizable version of an SR: Signals are sampled after a suitable band selection filter.
tran
sm
itre
ce
ive radio frontend
radiofrequency
RF
basebandprocessing
to u
se
rfr
om
us
er
analog-to-digitalconversion
A/D
dataprocessing
Everything is in Place
HOLD ON TO YOUR SEATS
Why Digital Communications?
But Let Your Communications Be Yea, Yea: Nay, Nay:
Sermon on the Mount, Matthew, Ch. 5, verse. 37
For What So Ever is More Than These Cometh of Evil.
To Paraphrase the Great Bard
The World is an Analog Stage
In Which Digital
Plays A Bit Part
A Communication System
MODULATORINFORMATION
SOURCE
INFORMATION
DESTINATIONDEMODULATORCHANNEL
BANDLIMITED
AWGN
fx
Amplitude
Distribution
Spec tral
Distribution
Modulator and Demodulator
DATA
TRANSFORMS WAVEFORM
TRANSFORMS
SPECTRAL
TRANSFORMS
BITS
M-ARY
ALPHABET
BASEBAND
WAVEFORM
RADIO
FREQUENCY
WAVEFORM
DIGITAL ANALOG
MODULATOR
MODULATOR CHANNEL DEMODULATORBITS RF RF BITS
DATA
TRANSFORMS
WAVEFORM
TRANSFORMS
SPECTRAL
TRANSFORMSBITS
M-ARY
ALPHABET BASEBAND
WAVEFORM
RADIO
FREQUENCY
WAVEFORM
DIGITALANALOG
DEMODULATOR
Claude Shannon
Information is measurable.
Noise Does not Limit Fidelity.
'The world has only 10 kinds of people.
Those who get binary, and those who don't.'
DISCRETE CHANNEL DIGITAL
MODULATOR
DIGITAL
DEMODULATOR
BITS
M-ARY
ALPHABET
M-ARY
ALPHABET
DATA
TRANSFORMS WAVEFORM
TRANSFORMS
SPECTRAL
TRANSFORMS
SPECTRAL
TRANSFORMS WAVEFORM
TRANSFORMS
DATA
TRANSFORMS
BASEBAND
WAVEFORM
RF
CH
AN
NEL
RF
BASEBAND
WAVEFORM
BITS
Shannon’s Communication System
Shannon’s Model
BITS
BITS
BANDWIDTH
REDUCING
BANDWIDTH
PRESERVING
BANDWIDTH
EXPANDING
CH
AN
NEL
SOURCE
ENCODING
CHANNEL
ENCODING
CHANNEL
DECODING
SOURCE
DECODING
ENCRYPTION
DECRYPTION
Shannon’s Legacy
Communication System ResourcesBandwidthSignal to Noise RatioMemory and Computations
A Communication System needs a Computer in Modulator and Demodulator!
We have a Computer on Board!
We can use it to do some other Heavy Lifting
Four Pillars of Modern Communications
BAN
DW
IDTH
SIG
NAL t
o N
OIS
E R
ATIO
DATA T
RAN
SFO
RM
S
SIG
NAL T
RAN
SFO
RM
S
MODERN
COMMUNICATIONS
The Modulator Digital to Analog
Interface Moves Towards the RFBASEBAND
BASEBAND
BASEBAND
RF
RF
RF
M-ARY
M-ARY
M-ARY
TUNER
TUNER
TUNER
ANALOG
ANALOG
ANALOG
DIGITAL
DIGITAL
DIGITAL
SIGNAL
CONDITIONER
SIGNAL
CONDITIONER
SIGNAL
CONDITIONER
The Demodulator Analog to Digital
Interface Moves Towards the RFBASEBAND
BASEBAND
BASEBAND
RF
RF
RF
M-ARY
M-ARY
M-ARY
ANALOG
ANALOG
ANALOG
DIGITAL
DIGITAL
DIGITAL
TUNER
TUNER
TUNER
SIGNAL
CONDITIONER
SIGNAL
CONDITIONER
SIGNAL
CONDITIONER
SECOND GENERATION DSP
CENTRIC MODEL
SAMPLED DATA CHANNEL DIGITAL
MODULATOR DSP
MODULATOR
DSP
DEMODULATOR
DIGITAL
DEMODULATOR
BITS
M-ARY
ALPHABET
M-ARY
ALPHABET
DATA
TRANSFORMS WAVEFORM
TRANSFORMS
SPECTRAL
TRANSFORMS
SPECTRAL
TRANSFORMS WAVEFORM
TRANSFORMS
DATA
TRANSFORMS
BASEBAND
WAVEFORM
RF
CH
AN
NEL
RF
BASEBAND
WAVEFORM
BITS
ANALOG
SIGNALS DIGITAL
SIGNALS
DATA
SIGNALS
THIRD GENERATION
DSP CENTRIC MODEL
ANALOG CHANNEL DIGITAL
MODULATOR DSP
MODULATOR
DSP
DEMODULATOR
DIGITAL
DEMODULATOR
BITS
M-ARY
ALPHABET
M-ARY
ALPHABET
DATA
TRANSFORMS WAVEFORM
TRANSFORMS
SPECTRAL
TRANSFORMS
SPECTRAL
TRANSFORMS WAVEFORM
TRANSFORMS
DATA
TRANSFORMS
BASEBAND
WAVEFORM
RF
CH
AN
NEL
RF
BASEBAND
WAVEFORM
BITS
ANALOG
SIGNALS DIGITAL
SIGNALS
DATA
SIGNALS
Satellite Broadcasts384 MP3 Channels to
Earth Stations
Demodulate all MP3 ChannelsRemodulate as FM Channels
Task: Replace Legacy Transceiver
An Interesting Problem
What size room is required to house new DSP based Transceiver?
Equipment Bay: 192-Stereo FM Modulators
Conversation with Client! How big a room will we need to house the DSP
version of this Transceiver?
Answer: I think it will fit on one chip.
Response: Don’t be Absurd, You Can’t Pack a
Room into a Single Chip!
Results: 48-Analog Devices Blackfin Processors
to Demodulate 192 MP3 Stereo Channels.
1 Virtex V-4 for 192 Digital Stereo FM Modulators
and 256 Channel Channelizer @ 293 kHz
Bandwidth per channel. (60% of Chip)
Only Description of Legacy System
Why I Like DSP!
A Smaller
Package
2-U High, Full Rack Width
H 3.5 in, 8.89 cmW 17.0 in, 43.18 cmD 9.4 in, 23.88 cm
Receiver Built with Ideal Parts
Analog I/QDown Convert
Dig ita l I/QDown Convert
AnalogLow Pass
Filters
AnalogBand Pass
Filter
A-to-DConverters
Rest ofReceiver
ChannelEqualize
Synthesizer DDSClock
Analog I/QDown Convert
Dig ita l I/QDown Convert
AnalogLow Pass
Filters
AnalogBand Pass
Filter
A-to-DConverters
DC
Cancel
PhaseBalance
GainBalance
Rest ofReceiver
FilterCom pensate
ChannelEqualize
Synthesizer Clock DDSAnalog Signals Digita l Signals
and with Real Parts (Dirty RF)
Genies in your Radio
•Timing Recovery Genie•Carrier Recovery Genie•Automatic Gain Control Genie•Squelch Genie•Equalizer Genie•SNR Estimator Genie
Assistant Genies in Your Radio
•DC Cancelling Genie•I-Q Balancing Genie•Line Cancelling Genie•Power Amplifier Predistortion Genie•Peak-to-Average Reduction Genie•DAC Sin(x)/x Predistortion Genie•Time Interleaved ADC Genie•Signal Whitening Genie•White Space Detection Genie
Are you a good fortune teller?
CTO of Comstream asked to see me.
He asked me to design a DSP based Receiver
to span 10-kb/s to 10-Mb/s in 1-b/s steps.
I laughed. I thought he was joking.
No. He was Serious.
His parting comment: It likely can not be done at
the moment! DSP advances would enable it
some time in the future! He expected me to
predict the dawn of the coming horizon so he
would be prepared to greet it!
All he had to do was ask
It took me a week to do the design!
He couldn’t believe all he had to do was ask!
US Patent 5,504,785, “Digital Receiver
for Variable Symbol Rate Communications”
An important lesson here.
If you expect little, you get little!
If you expect a lot, you get a lot!
Don’t ask for the Impossible
You will be disappointed!
DSP Radio (DSP Everywhere!)
Polyphase
Matched
Filter
32-to-1
Polyphase
Derivative
Matched
Filter
Polyphase
Band-Edge
Filter
Timing
Loop
Equalizer 2-to-1
Down
sample
LMS
Algorithm
Carrier
Loop Filter
& DDS
Carrier
Loop Filter
& DDS
Detec tor
20 Msmpl/S
10 Msmpl/S
20 Msmpl/S
-
*
Channel Filtering, Channel Estimate, Equalization, AGC, DC-Cancelling, I-Q Balance, Line Canceller,Interference Canceller, Matched Filter, SNR Estimate, Band Edge Filter, Frequency Lock Loop, Carrier Lock Loop, Interpolator, Timing Lock Loop,
Actually, A design Project For my Modem Design Class
Constellations of
Channel +k and -k
Crosstalk Between Channels k and –k
Due to Gain and Phase Imbalance
Constellation after Gradient Descent
Correction of Gain and Phase Imbalance
Digital Signal Processing Radio (1)
Processing Discrete (in Amplitude)
Approximations of Sampled (in Time) Signal
Representation of Analog Waveforms.
DSP Based Radio can
Process Analog or Digital Signals
DSP can Process non-RF Signals:
Audio and Video
Software Defined Radio (SDR)
A Software Defined Radio System
Applies Software for Control of
Network Protocol
DSP Algorithms
Programmable Digital Hardware,
Programmable Analog Hardware
In RF, IF, and Baseband Regimes
Software Defined Radio
Tunable Filters
and LNA
Tunable Filters
and LNA
User Interface
Periphials
Power
ManagerTunable Filters &
Power Amplifier
Mixer
Mixer
IF/AGC
IF/AGC
ADC
DAC
DSPs GPPs
Spec ialized
Co-Processors
FPGAs
D
up
lexe
r, A
nte
nna
Ma
na
ge
me
nt
& T
un
er
RF-Front End Digital Back End
Cognitive Radio (CR)
Cognitive radios, aware of channel
conditions and activity, change its operating
parameters to enable reliable, interference
free, communications.
Factors include external radio environment
such as spectrum availability, network state,
and its internal environment such as
available resources, and user behavior.
Parable of the Six Blind MenThe First Blind Man Touched its Sturdy Side:
“This is Very Much Like a Wall” The Second Blind Man Touched its Smooth Round Sharp Tusk
“Clearly this is Like a Large Spear”
The Third Blind Man
Grasped its
Wiggling Trunk:
“Undoubtedly, This is like a Mighty
Snake”
The Fourth Blind Man
Felt its Flapping
Ears.
“This surely is like a
Great Fan to Stir the Air”
The Fifth Blind Man Leaned against its huge leg: “This is Like a Sturdy Tree”
The Sixth Blind Man seized its swinging tail; “For sure this is like a Hanging Rope”
Parable Continued
A Seventh
Blind Man
came upon
the scene and
proclaimed:
“Surely all your
senses have
abandoned you,
for it is clear to
all that this is a
Software
Defined
Radio”
SOFTWAREDEFINEDRADIOMAN
Is Open For Questions