rf100

Course RF100

Wireless Wireless CDMA CDMA RF RF Engineering: Engineering: Week Week 11

February, 2005

RF100a(c) 2005 Scott Baxter v2.0

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Integrated RF/CDMA/Performance Training Course RF100: RF Introduction, CDMA Principles, Understanding System Design & Performance Issues Monday •Wireless Industry Intro. •Modulation Techniques •Mult. Access Methods •Wireless system Architectures •RF Propagation •Physics •Mechanisms •Models •Link Budgets •Margins •Pred. Tools •Meas. Tools

Tuesday •Wireless Antennas •Intro: Principles •Families/Types •Choosing the right antenna •Selecting ants. •Other devices •Tests/Problems •Traffic Engineering •Units, principles •Traffic tables •Wireless appls.

Wednesday

Thursday

•Introduction to CDMA •Spread Sp. Principles •CDMA’s Codes •Fwd & Rev Channels •System Architecture •Power Control •Phone Architecture •Handoff Process •Ec/Io, Eb/No •phone’s limitations •Call Processing •CDMA Messages

•CDMA Flow Examples •Critical CDMA Issues •Interference control •Managing Soft HO% •Capacity constraints •Forward big picture •Reverse big picture •Sys Architecture details •Lucent •Nortel •Motorola

Friday •System Growth Mgt. •Stopgap measures •Longterm strategies •Multiple carriers •Intercarrier Handoff •Intro to Optimization •Perspectives •Bottom-up: mobile •Top-down: OMs •Survey of Tools •Performance Goals •Design Implications

Course RF200: Optimization Principles, Tools, Techniques, and Real-Life Examples/Exercises Day 1 •Optimization Overview •RF100 Fast Review •General Q&A •Meet the CDMA performance indicators •Signatures of CDMA transmission problems •The classic CDMA death scenario •Introduction to Performance Data •System-side tools and their implications

February, 2005

Day 2

Day 3

•Intro to Mobile Tools •Collection Tools •Grayson, LCC, HP •PN Scanners •HP, Grayson, Berkeley •Post-processing •Analyzer, DeskCat •Drive-test Demo files •Grayson •LCC •Intro to Post-Processing •Analyzer, DeskCat

•Handsets as test tools •Drive-Test Demo Lab •RSAT/Collect 2000! •Grayson Inspector •Data Analysis and PostProcessing •Analyzer, DeskCat •what events did you see? •Identifying root causes •Parameter & configuration changes

Day 4 •Operators’ Corporate RF Benchmarking Overview •PN Scanner Lab •HP, Grayson, Berkeley •Gathering data, interpreting problems •Applied Optimization •common scenarios

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RF100 Chapter 1

Wireless Wireless Systems: Systems: How How did did we we get get here? here? What’s What’s itit all all about? about?

MTS, IMTS

February, 2005

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Radio Hasn’t Been Around Long! Days before radio..... • 1680 Newton first suggested concept of spectrum, but for visible light only N

LF HF VHF UHF MW IR

S

U

UV XRAY

• 1831 Faraday demonstrated that light, electricity, and magnetism are related • 1864 Maxwell’s Equations: spectrum includes more than light • 1890’s First successful demos of radio transmission

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First Wired Communication: Telegraphy „ Samuel F.B. Morse had the idea of the telegraph on a sea cruise in the 1833. He studied physics for two years, and In 1835 demonstrated a working prototype, which he patented in 1837. „ Derivatives of Morse’ binary code are still in use today „ The US Congress funded a demonstration line from Washington to Baltimore, completed in 1844. „ 1844: the first commercial telegraph circuits were coming into use. The railroads soon were using them for train dispatching, and the Western Union company resold idle Samuel F. B. Morse time on railroad circuits for public telegrams, nationwide at the peak of his career „ 1857: first trans-Atlantic submarine cable was installed

Submarine Cable Installation news sketch from the 1850’s February, 2005

Field Telegraphy during the US Civil War, 1860’s

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Wired Communication for Everyone: Telephony „ By the 1870’s, the telegraph was in use all over the world and largely taken for granted by the public, government, and business. „ In 1876, Alexander Graham Bell patented his telephone, a device for carrying actual voices over wires. „ Initial telephone demonstrations sparked intense public interest and by the late 1890’s, telephone service was available in most towns and cities across the USA

Alexander Graham Bell and his phone from 1876 demonstration February, 2005

Telephone Line Installation Crew 1880’s

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Radio Milestones „ 1888: Heinrich Hertz, German physicist, gives lab demo of existance of electromagnetic waves at radio frequencies „ 1895: Guglielmo Marconi demonstrates a wireless radio telegraph over a 3-km path near his home it Italy „ 1897: the British fund Marconi’s development of reliable radio telegraphy over ranges of 100 kM „ 1902: Marconi’s successful trans-Atlantic demonstration „ 1902: Nathan Stubblefield demonstrates voice over radio Guglielmo Marconi „ 1906: Lee De Forest invents “audion”, triode vacuum tube radio pioneer, 1895 • feasible now to make steady carriers, and to amplify signals

MTS, IMTS

„ 1914: Radio became valuable military tool in World War I „ 1920s: Radio used for commercial broadcasting „ 1940s: first application of RADAR - English detection of incoming German planes during WW II „ 1950s: first public marriage of radio and telephony MTS, Mobile Telephone System „ 1961: transistor developed: portable radio now practical „ 1961: IMTS - Improved Mobile Telephone Service Lee De Forest „ 1970s: Integrated circuit progress: MSI, LSI, VLSI, ASICs vacuum tube inventor „ 1979, 1983: AMPS cellular demo, commercial systems

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Overview of the Radio Spectrum Frequencies Used by Wireless Systems AM

0.3

0.4

0.5

0.6

LORAN

0.7 0.8 0.9 1.0

1.2

Marine

1.4 1.6 1.8 2.0

2.4

Short Wave -- International Broadcast -- Amateur

3

4

5

6

VHF LOW Band

30

40

7

8

9

VHF TV 2-6

50

60

70

10

12

FM

80 90 100

CB

14 16 18 20 22 24 26 28 30 MHz 7 30,000,000 i.e., 3x10 Hz

VHF VHF TV 7-13

120 140 160 180 200

0.3

0.4

0.5

3

4

5

UHF TV 14-69

Broadcasting February, 2005

0/6

6

300 MHz

2.4

3.0 GHz

GPS

0.7 0.8 0.9 1.0

7

240

300,000,000 i.e., 3x108 Hz DCS, PCS

Cellular UHF

3.0 MHz

3,000,000 i.e., 3x106 Hz

8

9

10

1.2

1.4 1.6 1.8 2.0

12

14 16 18 20 22 24 26 28 30 GHz 10

3,000,000,000 i.e., 3x109 Hz

30,000,000,000 i.e., 3x10 Hz

Land-Mobile Aeronautical Mobile Telephony Terrestrial Microwave Satellite RF100a(c) 2005 Scott Baxter v2.0

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Development of North American Cellular „ In the late 1970’s, the FCC (USA Federal Communications Commission) allocated 40 MHz. of spectrum in the 800 MHz. range for public mobile telephony. „ FCC adopted Bell Lab’s AMPS (Advanced Mobile Phone System) standard, creating cellular as we know it today • The USA was divided into 333 MSAs (Metropolitan Service Areas) and over 300 RSAs (Rural Service Areas) „ In 1987, FCC allocated an additional 10 MHz. of “expanded spectrum” „ By 1990, all MSAs and RSAs had competing licenses granted and at least one system operating. „ In the 1990’s, additional technologies were developed for cellular • TDMA (IS-54,55,56, IS-136) (also, GSM in Europe/worldwide) • CDMA (IS-95) „ US Operators did not pay for their spectrum, although processing fees (typically $10,000’s) were charged to cover license administrative cost

333 MSAs 300+ RSAs

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North American Cellular Spectrum Uplink Frequencies (“Reverse Path”) 824

835

A

Downlink Frequencies (“Forward Path”) 845

849

B

825

Frequency, MHz

870

A

Paging, ESMR, etc. 846.5

Ownership and Licensing

890

880

B

869

891.5

Frequencies used by “A” Cellular Operator Initial ownership by Non-Wireline companies Frequencies used by “B” Cellular Operator Initial ownership by Wireline companies

„ In each MSA and RSA, eligibility for ownership was restricted • “A” licenses awarded to non-telephone-company applicants only • “B” licenses awareded to existing telephone companies only • subsequent sales are unrestricted after system in actual operation February, 2005

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Development of North America PCS „ By 1994, US cellular systems were seriously overloaded and looking for capacity relief • The FCC allocated 120 MHz. of spectrum around 1900 MHz. for new wireless telephony known as PCS (Personal Communications Systems), and 20 MHz. for unlicensed services • allocation was divided into 6 blocks; 10-year licenses were auctioned to highest bidders „ PCS Licensing and Auction Details • A & B spectrum blocks licensed in 51 MTAs (Major Trading Areas ) • Revenue from auction: $7.2 billion (1995) • C, D, E, F blocks were licensed in 493 BTAs (Basic Trading Areas) • C-block auction revenue: $10.2 B, D-E-F block auction: $2+ B (1996) • Auction winners are free to choose any desired technology • About half the C-block winners were unable to pay for their licenses. They wrangled in and out of court, with final disposition in 2005.

51 MTAs 493 BTAs

PCS SPECTRUM ALLOCATIONS IN NORTH AMERICA A

D

B

E F

C

15

5

15

5

15

1850 MHz. February, 2005

5

unlic. unlic. data voice

1910 MHz.

A

D

B

E F

C

15

5

15

5

15

5

1930 MHz.

RF100a(c) 2005 Scott Baxter v2.0

1990 MHz. 1 - 11

Major PCS Auction Winners Sprint PCS CDMA

AT&T Wireless IS-136

Primeco CDMA Western Wireless Pacific Bell

Aerial OmniPoint

GSM

BellSouth Powertel

February, 2005

The Largest Players, Areas, and Technologies „ Sprint PCS • Began as partnership of Sprint, TCI, Cox Cable • Bid & won in 2/3 of US markets A or B blocks • Sprint won D and/or E blocks in remaining markets • CDMA: Mix of Nortel, Lucent, Motorola „ AT&T Wireless Systems • Bid & won a majority of markets in A&B Blocks • will combine and integrate service between its new PCS 1900 systems and its former McCaw cellular 800 MHz. properties • IS-136: mix of Lucent and Ericsson equipment „ Other CDMA Operators • Primeco: partnership of various operators • GTE, others „ GSM Operators • Western Wireless, OmniPoint, BellSouth, GTE, Powertel, Pacific Bell • Mix of Ericsson, Nokia, and Nortel networks „ For auction details, check www.fcc.gov RF100a(c) 2005 Scott Baxter v2.0

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Progress in Radio Technology Development Systems, Signals, & Devices Radio Communication Systems HFAmateur

VHFLand Mobile

Mobile Telephony30-50MHz

Marine Military

Microwave Microwave Satellite RADAR Point-to-Point AM Bcst1MHz FM Bcst100MHz VHF-TV Bcst UHF-TV Bcst

Modulation CW AM FSK Devices

FM PM PSK QAM

Spark Vacuum Tubes

1910 February, 2005

1920

1930

150MHz 450MHz 800MHz 1900MHz

DQPSK GMSK

Discrete MSI VLSI, Transistors LSI ASICS 1940

1950 1960 Time

RF100a(c) 2005 Scott Baxter v2.0

1970

1980

1990 2000 1 - 13

Evolution of Wireless Telephony Standards, Technologies, & Capacity Standards Evolution MTS150MHz

IMTS150MHz

AMPS800MHz N_AMPS D-AMPS CDMA

450MHz

Technology Evolution Analog AM, FM

PCS1900MHz GSM CDMA AMPS, etc

ESMR800MHz

Digital Modulation

Access Strategies

DQPSK GMSK

FDMA TDMA CDMA

Vacuum Tubes Discrete Transistors

MSI

LSI

VLSI, ASICs

System Capacity Evolution - Users Dozens

Hundreds

100,000’s

1960

1990

AMPS = Advanced Mobile Phone System N_AMPS = Narrowband AMPS (Motorola) D-AMPS = Digital AMPS (IS-54 TDMA) ESMR = Enhanced Specialized Mobile Radio February, 2005

1,000,000’s

PCS-1900 = FDMA = TDMA = CDMA =

Personal Communication Systems Frequency Division Multiple Access Time Division Multiple Access Code Division Multiple Access

RF100a(c) 2005 Scott Baxter v2.0

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Summary: Wireless Economics and Logistics Trends in Radio Communications Technology:

Analog

System Organization:

Centralized

Digital Distributed

Cost per Subscriber System Capacity System Complexity Radio Frequencies Used Time February, 2005

RF100a(c) 2005 Scott Baxter v2.0

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RF100 Chapter 2

Wireless Wireless Systems: Systems: Modulation Modulation Schemes Schemes and and Bandwidth Bandwidth

Q axis

fc Lower Sideband

Upper Sideband

b a

1

0 1 0

fc

c

φ

I axis

QPSK

1

0 1 0

Q axis r

a

fc

1

0 1 0

b

c

φ

I axis

p v π/4 shifted DQPSK

fc

February, 2005

RF100 v2.0 (c) 2005 Scott Baxter

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Characteristics of a Radio Signal SIGNAL CHARACTERISTICS The complete, timevarying radio signal

Natural Frequency of the signal

S (t) = A cos [ ωc t + ϕ ] Amplitude (strength) of the signal

Phase of the signal

Compare these Signals: Different Amplitudes

Different Frequencies Different Phases February, 2005

„ The purpose of telecommunications is to send information from one place to another „ Our civilization exploits the transmissible nature of radio signals, using them in a sense as our “carrier pigeons” „ To convey information, some characteristic of the radio signal must be altered (I.e., ‘modulated’) to represent the information „ The sender and receiver must have a consistent understanding of what the variations mean to each other • “one if by land, two if by sea” „ Three commonly-used RF signal characteristics which can be varied for information transmission:

• Amplitude • Frequency • Phase

RF100 v2.0 (c) 2005 Scott Baxter

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AM: Our First “Toehold” for Transmission „ The early radio pioneers could only turn their crude transmitters on and off. They could form the dots and dashes of Morse code. The first successful radio experiments happened during the mid-1890’s by experimenters in Italy, England, Kentucky, and elsewhere. „ By 1910, vacuum tubes gave experimenters better control over RF power generation. RF power could now be linearly modulated in step with sound vibrations. Voices and music could now be transmitted!! Still, nobody anticipated FM, PM, or digital signals. „ Commercial public AM broadcasting began in the early 1920’s. „ Despite its disadvantages and antiquity, AM is still alive: • AM broadcasting continues today in 540-1600 KHz. • AM modulation remains the international civil aviation standard, used by all commercial aircraft (108-132 MHz. band). • AM modulation is used for the visual portion of commercial television signals (sound portion carried by FM modulation) • Citizens Band (“CB”) radios use AM modulation • Special variations of AM featuring single or independent sidebands, with carrier suppressed or attenuated, are used for marine, commercial, military, and amateur communications

SSB LSB USB February, 2005

RF100 v2.0 (c) 2005 Scott Baxter

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Amplitude Modulation (“AM”) Details TIME-DOMAIN VIEW of AM MODULATOR

mn(t)

a

Σ

+

x(t)

+ 1

cos ωc

x(t) = [1 + amn(t)]cos ωc t where: a = modulation index (0 < a 10 dB. „ AM demodulation can also be performed by coherent detectors • incoming signal is mixed (multiplied) with a locally generated carrier • enhances performance when S/N ratio is poor (