A Short History of RadioA Short History of Radioand Signal Processing in and Signal Processing in
Modern RadiosModern Radios
A Short History of RadioA Short History of Radioand Signal Processing in and Signal Processing in
Modern RadiosModern Radiosfred harrisfred harris
29-May 2007
Pulse Train
What The Customer Wants
What the Customer Will Pay
MORE MORE MORE MORE
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MORE
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MORE
MO RE MO RE MO RE
MORE MORE
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MORE MORE
MORE
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MORE
MORE
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MORE
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MORE
RR E
MORE
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MORE
When the Customer wants it.
MORE MORE MORE MORE
MORE MORE MORE MORE MORE
MORE
MORE
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MORE
MO RE MO RE MO RE
MORE MORE
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RR E
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The Size Customer Wants.
Early Communication at a Distance†
776 BC Homing pigeons used to send message – the winner of the Olympic Games to the Athenians.200-100 BC Relay stations use fire messages to relay messages-
station to station.
37 AD Heliographs - mirrors send messages to Roman Emperor Tiberius.
1793 AD Claude Chappe invents the first long-distance optical semaphore telegraph line.
(†Communicating Faster Than A Person Can Run)
Very Early Communications at a Distance: Free Space Acoustic and Optical
Channels
Drums, Whistles,Cannon Fire
Semaphore, Ship Flags, Heliograph, Signal (Aldis) Lamp
Claude Chappe 1793 Optical Telegraph
Smoke Signals, Beacon Fires
Signal Fires: Early Warning of Approaching
Enemy
Carrier Pigeons in WW-1
A Time Line
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
Telecommunications!Applying Maxwell Equations to communication Systems
Maxwell's equations (1873)
magnetic field
electric field
electric displacement
magnetic flux density
current density
volume charge density
rot H J D
rot E B
div D
div B 0
H
E
D
B
J
.
.
James Clerk Maxwell, 1831 – 1879
Milestones in Electromagnetic Communications
H.C. Orsted, 1777-1841 “Electrici and Magneticam” 1820
Fraday, 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
G. Marconi, Radio 1895
Valdemar Poulsen, Continuous Radio Waves 1905
Lee de Forest, Audion 1907
Edward Armstrong, Super-regenerative, Superheterodyne 1917 Frequency Modulation, 1934
Disruptive Technology
The electric telegraph arrived in the early 19th
century and redefined communications at a distance. It required the confluence of three ingredients: 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
B
2 out of 5 Coding (5*4 = 20 )
The Cooke and Wheatstone first commercial electrical telegraphentered use on the Great Western Railway on April 9, 1839.
It ran for 13 miles from Paddington Station to West Drayton On January 1, 1845 John Tawell was apprehended following the use of a needle telegraph message from Slough to Paddington.
This is thought to be the first use of the telegraph to apprehend a murderer.
The message was: A murder has just been committed at Salt Hill and the suspected Murderer was seen to take a first class ticket to London by the train that left Slough at 7:42 pm. He is in the garb of a Kwaker with a brown great coat on which reaches his feet. He is in the last compartment of the second first-class carriage
Single Needle and 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 quoted report 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 Phones Engineers 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 across the Atlantic Ocean.
1914 First cross continental telephone call made.
1916 First radios with tuners different stations.
1930 First television broadcasts in the United States.
The Players• Wireless• Radio• Analog Radio• Digital Radio• DSP Radio• Software Defined
Radio• Cognitive Radio
It all Started with…..
Heinrich Rudolph Hertz,1847-1894
Shocking!
1. Induction Coil Produces High Voltage
2. Spark Produces Electromagnetic Waves3. Electromagnetic waves induce voltage in
resonator, producing small spark in spark gap.
Guglielmo Marconi, 1874-1937
December 12 1901 Spark Gap Transmitter
Early Radios Were Mechanical(Many Moving Parts)
SPARK TRANSMITTERS
Spark Gap Wireless Transmitter
(Damped Oscillations)
Sparks came in all sizes
Marine Spark Transmitter
Radio Operators aboard Ship Were
Called
SparkyBecause they Operated the
Spark Transmitter
Marconi Tower Radio
2 KW 500 cycle quenching transmitter
Mobile Communications: Communicate to a moving Train
150 ft Antenna stretched across 3-railway cars
(187.4 kilocycles, 1600 Meters)
The Eiffel TowerThe 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 world’stitle for the world’s tallest structure till 1930, when it was surpassed by the Chrysler Building.
Eiffel tried to find practical applications for his tower. He wanted the tower to work, to pay its way. He 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.
Valdemar Poulsen, 1869-1942
Continuous (Undamped) Carrier
Arc Generator
Poulsen Arc Transmitter
Lee De Forest, 1877-1961
Patent No. 879532
Put those sparks to rest!
The path to the Triode Thermonic Valve,Thomas Edison, John Fleming, Lee de Forest
Edwin Armstrong, 1890-19541912 regenerative receiver
Regenerative Receiver
A little Feedback Goes a Long Way
Tuned RF Radio
Early Mobile Communications
It may not be safe todrive while using your mobile phone!
Edwin Armstrong’s Super Heterodyne
Receiver
DETAM PAM P AM P
AM P
ANT
IF IFRF
From Disclosure: June 3, 1918
Replacing the Vacuum Tube
Shockley, Brattain and BardeenSolid State Amplifier
1947
Integrated Circuits
Robert Noyce, Intel
Jack Kilby, TI
1958
Noyce Founded IntelTed Hoff worked for Noyce
Kilby Awarded Nobel Prize in 2000
20102000199019801970196019501947
1,000
10,000
100,000
1,000,000
10,000,000
100,000,000
1,000,000,000
10,000,000,000
8080 4,500
8088 29,000
286 134,000
386 275,000
486 1.2 MillionPentium 3.1 Million
Pentium IICeleron 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
1977Apple II
1947TransistorInvented
1965Gordon MooreStates his famousaxiom, later calledMoore’s law
1958Jack Kilby (TI) &Robert Noyce (intel) InventIntegrated Circuit
1983 Motorola FirstMobile Phone
1991 Kodak FirstDigital Camera
1996 DVDPlayers
1999 Blackberry
More, More, MooreCritics have predicted the imminentdemise of Moore’s law ever sinceGordon Moore stated it in 1965.Electrical Engineers continue todefy physical challenges, squeezing ever morecircuitry into less spaceand making informationfly ever moreswiftly.
We all own a Billion Transistors
NEXT-GENERATION VIRTEX FAMILY FROM XILINX TO TOP ONE BILLION TRANSISTOR MARK
Eiffel Tower Contains 18,084 PartsIt is Fastened together by 2.5 Million Rivets
The 1 billion transistor processor: who will be first?Semiconductor International, March 2003
Future Microprocessors - How to use a Billion TransistorsSeptember 1997 issue of IEEE Computer
The World grows more transistors than it grows grains of rice!
Harry Nyquist,(1889-1960)
fS>BW
The Sampling Theorem
Analog-to-Digital Converter
Digital-to-Analog Converter
Start of the Modern eraADC and DSP Insertion
Sample The Intermediate Frequency
Stage
Perform Timing and Carrier Synchronization in DSP Land
The Modern Era
Software Radio (SR): An ideal SR directly samples the antenna output.
Joe Mitola, 2000
Digital Radio (DR): The baseband signal processing is invariably implemented on a DSP.
Software Defined Radio (SDR): An SDR is a realizable version of an SR: Signals are sampled after a suitable band selection filter.
tran
smit
rece
ive radio frontend
radiofrequency
RF
basebandprocessing
to u
ser
from
use
r
analog-to -digitalconversion
A/D
dataprocessing
control(param etrization)
Everything is in Place
A Simple Communication System
MODULATORINFORMATION SOURCE
INFORMATION DESTINATIONDEMODULATORCHANNEL
BANDLIMITED
AWGN
fx
AmplitudeDistribution
SpectralDistribution
All Channels are Waveform Channels
Repeaters are not!
ATTN
ATTN
ATTN
ATTN
ATTN
ATTN
AMP AMPAMP
s(t)+N1
s (t)1 s (t)2 s (t)K
s(t) +N2+N1 s(t) +NK+N +N +...1 2
N1(t)
N1(t)
NK(t)
NK(t)
N2(t)
N2(t)
s(t)
s(t)
ANALOG REPEATER CHANNEL
DIGITAL REPEATER CHANNEL
^ ^ ^
Why Digital Communications?
But Let Your Communications Be
Yea, Yea: Nay, Nay:For What So Ever is
More Than These Cometh of Evil.
Sermon on the Mount, Matthew, Ch. 5, verse. 37
Probability of Error
10-0
10-3
10-1
10-4
10-6
10-2
10-5
10-7
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
0.8 1.0 1.5 2.0 3 .0 4.0 5.0 6.0
10 log ( )=10 log ( )10 10Eb
Eb
Eb
N0
N0
N0 /2
1
1
d/2
d/2
d/22
2
2
[ ]
SNR(dB)
=
SNR=9.6 dB
P(e)=10-5
Slope at 10-5
1 Decade/dBERFC( )
Prob
abilit
y of E
rror,
AWG
N
4.27
9.6
d
P(e)
ConditionalDensity Functions
Bottom Line
5100
10
10 10
: ( ) 10 : Analog
: 10 ( ) 10100
10 ( ) 10 10 (100) 30
Given P
SNRThen Log dB
Log SNR dB Log dB
5100
51
71
: ( ) 10 :
: 100 ( ) 10
( ) 10 12
Given P Digital
Then P
P SNR dB
5100100 Repeaters, ( ) 10P
Modulator and Demodulator
MODULATOR CHANNEL DEMODULATORBITS RF RF BITS
DATATRANSFORMS
WAVEFORMTRANSFORMS
SPECTRALTRANSFORMS
BITS
M-ARYALPHABET
BASEBANDWAVEFORM
RADIOFREQUENCYWAVEFORM
DIGITAL ANALOG
MODULATOR
DATATRANSFORMS
WAVEFORMTRANSFORMS
SPECTRALTRANSFORMS
BITS M-ARYALPHABET
BASEBANDWAVEFORM
RADIOFREQUENCYWAVEFORM
DIGITALANALOG
DEMODULATOR
Claude Shannon
'The world has only 10 kinds of people.
Those who get binary, and those who don't.'
Noise Does not Limit Fidelity.
Information is measurable.
Distortion is Controllable.
Shannon’s Digital ModelDISCRETE CHANNEL DIGITAL
MODULATOR
DIGITALDEMODULATOR
BITS
M-ARYALPHABET
M-ARYALPHABET
DATATRANSFORMS
WAVEFORMTRANSFORMS
SPECTRALTRANSFORMS
SPECTRALTRANSFORMS
WAVEFORMTRANSFORMS
DATATRANSFORMS
BASEBANDWAVEFORM
RF
CHAN
NEL
RF
BASEBANDWAVEFORM
BITS
Shannon’s Model
BITS
BITS
BANDWIDTH REDUCING
BANDWIDTHPRESERVING
BANDWIDTHEXPANDING
CHAN
NEL
SOURCEENCODING
CHANNELENCODING
CHANNELDECODING
SOURCEDECODING
ENCRYPTION
DECRYPTION
It’s all Bits! Bits in, Bits out!
Shannon’s Legacy• Communication System Resources
BandwidthSignal to Noise RatioComputational Complexity
• A Communication System needs a Computer in Modulator and
Demodulator!• We have a Computer on Board!
• We can use it to do some Heavy Lifting
The Four Pillars of Modern Communications
BA
ND
WID
TH
SIG
NA
L to
NO
ISE
DA
TA
TR
AN
SFO
RM
S
SIG
NA
L TR
AN
SFO
RM
S
MODERNCOMMUNICATIONS
The Modulator Digital to Analog Interface Moves Towards the RF
BASEBAND
BASEBAND
BASEBAND
RF
RF
RF
M-ARY
M-ARY
M-ARY
TUNER
TUNER
TUNER
ANALOG
ANALOG
ANALOG
DIGITAL
DIGITAL
DIGITAL
SIGNALCONDITIONER
SIGNALCONDITIONER
SIGNALCONDITIONER
The Demodulator Analog to Digital Interface Moves Towards the RF
BASEBAND
BASEBAND
BASEBAND
RF
RF
RF
M-ARY
M-ARY
M-ARY
ANALOG
ANALOG
ANALOG
DIGITAL
DIGITAL
DIGITAL
TUNER
TUNER
TUNER
SIGNALCONDITIONER
SIGNALCONDITIONER
SIGNALCONDITIONER
First Generation DSP Receiver
LOW-PASS FILTER
LOOPFILTER
LOOPFILTER
I-F FILTER
IMAGEREJ ECT FILTER
MATCHED FILTER
FIRST LO
SAMPLER DATADETECTOR
PHASEDETECTOR
CARRIER VCO
TIMING VCO
LNA
TUNING
GAIN
Second Generation DSP Receiver
LOW-PASS FILTER
LOOPFILTER
LOOPFILTER
I-F FILTER
IMAGEREJ ECT FILTER
MATCHED FILTER
FIRST LO
SAMPLER
DATADETECTOR
PHASEDETECTOR
CARRIER VCO
TIMING VCO
LNA
TUNING
GAIN
LOW-PASS FILTER
LOOPFILTER
LOOPFILTER
I-F FILTER
IMAGEREJ ECT FILTER
MATCHED FILTER
FIRST LO
SAMPLER DATADETECTOR
PHASEDETECTOR
CARRIER VCO
TIMING VCO
LNA
TUNING
GAIN
Third Generation DSP Receiver
LOW-PASS FILTER
LOOPFILTER
LOOPFILTER
I-F FILTER
IMAGEREJ ECT FILTER
MATCHED FILTER
FIRST LO
SAMPLER
DATADETECTOR
PHASEDETECTOR
CARRIER VCO
TIMING VCO
LNA
TUNING
GAIN
LOW-PASS FILTER
LOOPFILTER
LOOPFILTER
I-F FILTER
IMAGEREJ ECT FILTER
MATCHED FILTER
FIRST LO
SAMPLER
DATADETECTOR
PHASEDETECTOR
SECOND LO
SAMPLING CLOCK
CARRIER DDS
TIMING DDS
LNA
TUNING
GAIN
INTERPOLATOR
SECOND GENERATION DSP CENTRIC MODEL
SAMPLED DATA CHANNEL DIGITAL MODULATOR
DSP MODULATOR
DSP DEMODULATOR
DIGITALDEMODULATOR
BITS
M-ARYALPHABET
M-ARYALPHABET
DATATRANSFORMS
WAVEFORMTRANSFORMS
SPECTRALTRANSFORMS
SPECTRALTRANSFORMS
WAVEFORMTRANSFORMS
DATATRANSFORMS
BASEBANDWAVEFORM
RF
CHAN
NEL
RF
BASEBANDWAVEFORM
BITS
ANALOGSIGNALS
DIGITALSIGNALS
DATASIGNALS
THIRD GENERATION DSP CENTRIC MODEL
ANALOG CHANNEL DIGITAL MODULATOR
DSP MODULATOR
DSP DEMODULATOR
DIGITALDEMODULATOR
BITS
M-ARYALPHABET
M-ARYALPHABET
DATATRANSFORMS
WAVEFORMTRANSFORMS
SPECTRALTRANSFORMS
SPECTRALTRANSFORMS
WAVEFORMTRANSFORMS
DATATRANSFORMS
BASEBANDWAVEFORM
RF
CHAN
NEL
RF
BASEBANDWAVEFORM
BITS
ANALOGSIGNALS
DIGITALSIGNALS
DATASIGNALS
Mapping an Analog prototype to its Digital
Counterpart
ANALOG SIGNALPROCESSING
DIGITAL SIGNALPROCESSING
ANALOG TO DIGITALCONVERTER
DIGITAL TO ANALOGCONVERTER
ANALOGBLOCKS
DIGITALBLOCKS
x(t)
x(t)
x(n)
x(n)
x(t)
y(t)
y(t)
y(n)
y(n)
y(t)
PROTOTYPE ANALOG PROCESS
EQUIVALENT DIGITAL PROCESS
Good Advice!
• Don’t Copy Analog Legacy Prototype to DSP Domain.
• Legacy Designs include Compromises Appropriate for their Time.
• Return to First Principles!• Start with a fresh slate using current
resources and perspectives.
Signal Processing in Transmitter-I
Base Band Sigma-Delta ADC VCELPC Speech Source Coding Spectral Shaping Fixed Interpolation Arbitrary Interpolation I-Q Balance DC Canceling Digital Up-Conversion Sin(x)/(x) Predistortion IF Sigma-Delta DAC Direct Sequence Spreading Automatic Gain Control