Radio Spectrum Engineering - nsma.org

©2004 all rights reserved Allen Petrin [email protected]

Radio Spectrum Engineering

Allen Petrin Paul G. Steffes

Georgia Institute of TechnologySchool of Electrical and Computer Engineering


Outline

• Spectrum Measurement System

• Spectrum Study Results– Satellite Radio– MMDS– PCS– C-Band

• Frequency Agile Radio Technology


Radio Spectrum

• To Best Manage Radio Spectrum it is Desirable to Know its Usage

• Limited Past Spectrum Studies

• Incomplete Database of Transmitters and Receivers

• Propagation is Difficult to Predicate Accurately


Spectrum Study Variables

• Frequency (400 MHz – 7.2 GHz)• Time (short term usage, minutes)• Time Period (6 discrete time periods per day, hours) • Polarization (Linear: Horizontal & Vertical)• Azimuth (6 directions)• Location type (Urban, Rural, Suburban)

~2.5 billion data points per location!


Spectrum Study Variables

• Characterize Spectrum Usage

• Assists in Identifying Signals


Measurement of Variables

Time Period

Az

Full BW

Polarization

# Samples 3,600 Measurementsper 10 KHz


System Block Diagram

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Atlanta Measurement Site


RF Subsystem


Control and Data Acquisition


Spectrum Study Locations

• Urban– Atlanta (complete)

• Rural– PARI (80% complete)

• Suburban– Atlanta Area (to do)


PARI Measurement Site


PARIPisgah Astronomical Research Institute

• Radio and Optical Astronomy

• Frequencies: 8 KHz to 22 GHz

• Rural:– Pisgah National Forest– 53 km from Asheville, NC– 58 km from Greenville, SC– 127 km from Knoxville, TN


Satellite Radio

• Sirius Radio– 2320 MHz - 2332.5 MHz– 3 Highly Elliptical Orbit (HEO) Satellites– Terrestrial Repeaters

• XM Radio – 2332.5 MHz – 2345 MHz– 2 Geostationary Earth Orbit (GEO) Satellites

• Rock 85°W, Roll 115 °W– Terrestrial Repeaters


Urban UsageAverage Power

-130

-120

-110

-100

-90

-80

-70

2320 2326.25 2332.5 2338.75 2345

Frequency [MHz]

Rec

eive

d P

ower

Norm

aliz

ed to

Isot

ropic

Gai

n

[dB

m]

Average of AllNoise Floor

XMSirius


Urban UsageComparative Linear Polarization

-130

-120

-110

-100

-90

-80

-70

2320 2326.25 2332.5 2338.75 2345

Frequency [MHz]

Rec

eive

d Pow

er N

orm

aliz

ed to

Isot

ropi

c G

ain

[dB

m]

H Polz. Avg.V Polz. Avg.


Urban UsagePercentile Profile

-130

-120

-110

-100

-90

-80

-70

-60

-50

2320 2326.25 2332.5 2338.75 2345

Frequency [MHz]

Rec

eive

d P

ow

er N

orm

aliz

ed to Is

otr

opic

Gai

n

[dB

m]

99.99 Percentile99.9 Percentile99 Percentile90 Percentile50 Percentile10 Percentile


Urban UsageTime Period

-130

-120

-110

-100

-90

-80

-70

2320 2326.25 2332.5 2338.75 2345

Frequency [MHz]

Rec

eive

d P

ow

er N

orm

aliz

ed to

Isotr

opic

Gai

n

[dB

m]

Time Period 1Time Period 2Time Period 3Time Period 4Time Period 5Time Period 6


Urban UsageAzimuthal Direction

-130

-120

-110

-100

-90

-80

-70

2320 2326.25 2332.5 2338.75 2345

Frequency [MHz]

Rec

eive

d Pow

er N

orm

aliz

ed to

Isot

ropi

c G

ain

[dB

m]

0 Deg. Avg.60 Deg. Avg.120 Deg. Avg.180 Deg. Avg.240 Deg. Avg.300 Deg. Avg.


Rural UsageAzimuthal Direction

-130

-125

-120

-115

-110

2320 2326.25 2332.5 2338.75 2345

Frequency [MHz]

Rec

eive

d P

ower

Nor

mal

ized

to Is

otro

pic

Gai

n [d

Bm

] 0 Deg. Avg.60 Deg. Avg.120 Deg. Avg.180 Deg. Avg.240 Deg. Avg.300 Deg. Avg.

XM Rock

XM Roll

Sirius 1 Sirius 2


Multichannel Multipoint Distribution Service (MMDS)Instructional Television Fixed Service (ITFS)

• 2150 MHz - 2162 MHz• 2500 MHz - 2655 MHz • 2655 MHz - 2690 MHz

• FCC 03-56, Released: April 2, 2003– Notice of Proposed Rule Making and

Memorandum Opinion and Order


Urban MMDSPercentile Profile

-130

-120

-110

-100

-90

-80

-70

2150 2156 2162

Frequency [MHz]

Rec

eive

d P

ow

er N

orm

aliz

ed to Is

otr

opic

Gai

n

[dB

m]



Urban MMDSTime Period

-130

-125

-120

-115

-110

-105

-100

-95

-90

-85

2150 2156 2162

Frequency [MHz]

Rec

eive

d P

ower

Nor

mal

ized

to Is

otro

pic

Gai

n [d

Bm

]

12 AM - 4 AM4 AM - 8 AM8 AM - 12 PM12 PM - 4 PM4 PM - 8 PM8 PM - 12 AM


Urban MMDSAverage Power

-130

-120

-110

-100

-90

2500 2690

Frequency [MHz]

Rec

eive

d P

ow

er N

orm

aliz

ed to Is

otr

opic

Gai

n

[dB

m]


Urban MMDSAzimuthal Direction

-130

-120

-110

-100

-90

-80

2500 2690

Frequency [MHz]

Rec

eive

d Pow

er N

orm

aliz

ed to

Isotr

opi

c G

ain

[dB

m]

0 Deg. Avg.60 Deg. Avg.120 Deg. Avg.180 Deg. Avg.240 Deg. Avg.300 Deg. Avg.


Mobile Phone Standards

• 30 KHz– AMPS– IS-136 (TDMA)

• 200 KHz– GSM (TDMA)– GPRS (TDMA)– EDGE (TDMA)

• 1.25 MHz– IS-95 (CDMA)– 1xRTT, cdma2000

• 5 MHz– W-CDMA


PCS Frequencies

• PCS– 1850 – 1910 MHz Mobile– 1930 – 1990 MHz Base Station


Urban PCS UsageAverage Power

-130

-120

-110

-100

-90

-80

-70

-60

-50

1930 1940 1950 1960 1970 1980 1990

Frequency [MHz]

Rec

eive

d Pow

er N

orm

alized

to Is

otro

pic

Gai

n [d

Bm

]

BS AvgMobile Avg


Urban PCS UsagePercentile Profile

-130

-120

-110

-100

-90

-80

-70

-60

-50

-40

1930 1940 1950 1960 1970 1980 1990

Frequency [MHz]

Rec

eive

d Pow

er N

orm

aliz

ed to

Isotr

opic

Gai

n

[dB

m]

BS 99.99Mobile 99.99


Average Power

-130

-125

-120

1850 1860 1870 1880 1890 1900 1910

Frequency [MHz]

Rec

eive

d P

ower

No

rmal

ized

to Is

otro

pic

Gai

n [d

Bm

]

Mobile AvgBS Avg

Rural PCS Usage


Percentile Profile

-125

-120

-115

-110

-105

1850 1860 1870 1880 1890 1900 1910

Frequency [MHz]

Rec

eive

d P

ow

er N

orm

aliz

ed to Is

otr

opic

G

ain [dB

m]

Mobile 99.99 BS 99.99

Rural PCS Usage


Comparative Linear Polarization

-130

-125

-120

-115

-110

-105

-100

1850 1860 1870 1880 1890 1900 1910

Frequency [MHz]

Rec

eive

d P

ow

er N

orm

aliz

ed to

Iso

tro

pic

Gai

n [d

Bm

]


Mobile Urban PCS Usage


Comparative Linear Polarization

-130

-120

-110

-100

-90

-80

-70

-60

-50

1930 1940 1950 1960 1970 1980 1990

Frequency [MHz]

Rec

eive

d P

ower

Nor

mal

ized

to Is

otro

pic

Gai

n [d

Bm

]


Base Station Urban PCS Usage


Time Period

-130

-125

-120

-115

-110

-105

-100

1850 1860 1870 1880 1890 1900 1910

Frequency [MHz]

Rec

eive

d P

ower

No

rmal

ized

to Is

otro

pic

G

ain

[dB

m] 12 AM - 4 AM

4 AM - 8 AM8 AM - 12 PM12 PM - 4 PM4 PM - 8 PM8 PM - 12 AM

Mobile Urban PCS Usage


Time Period

-130

-120

-110

-100

-90

-80

-70

-60

-50

1930 1940 1950 1960 1970 1980 1990

Frequency [MHz]

Rec

eive

d P

ower

Nor

mal

ized

to Is

otr

opic

G

ain

[dB

m] 12 AM - 4 AM

4 AM - 8 AM8 AM - 12 PM12 PM - 4 PM4 PM - 8 PM8 PM - 12 AM

Base Station Urban PCS Usage


C-Band

• 3700 – 4200 MHz– Satellite Downlink– Fixed Microwave

• 5925 – 6425 MHz– Satellite Uplink– Fixed Microwave


Urban C-Band Usage: 3700 – 4200 MHzPercentile Profile

-135

-130

-125

-120

-115

-110

3700 3800 3900 4000 4100 4200

Frequency [MHz]

Rec

eive

d P

ower

Norm

aliz

ed to

Isot

ropic

Gai

n

[dB

m]



Urban C-Band Usage: 5925 – 6425 MHzPercentile Profile

-135

-130

-125

-120

-115

-110

-105

-100

-95

5925 6025 6125 6225 6325 6425

Frequency [MHz]

Rec

eive

d Pow

er N

orm

aliz

ed to

Isotr

opic

Gai

n

[dB

m]



Spectrum Measurement SystemDetection Ability

• Terrestrial Communication– Broadcast– Intermittent– Narrow Band (10 KHz RBW) – Spread Spectrum

• Terrestrial RADAR

• Satellite– LEO– GEO– HEO


Anthropogenic Noise

• FCC– “Interference Temperature”– “Environmental Noise Floor”

• Urban vs. Rural


Thermal Noise Profile From AtlantaPercentile Profile

-125

-120

-115

-110

4900 4910 4920 4930 4940 4950 4960 4970 4980 4990 5000

Frequency [MHz]

Rec

eive

d Pow

er N

orm

aliz

ed to Is

otro

pic

Gai

n

[dBm

]



Spectrum Study

Data Mining & Analysis

Improve Spectrum Utilization(Active Users)

Interference Information(Passive Users)

Reduce Pressure for Using Passive Bands


Time Line

Broadcast Radio

Broadcast TV

Microwave Comm.

2-way Radio

Mobile 2-way Radio

Cellular Comm.

Satellite Comm.

Freq. Agile Radio


Frequency Agile Radio(Dynamic Spectrum Radio)

(Software Defined Radio)(Cognitive Radio)

• More Utility from Spectrum• Not more Bits/Hz/Sec

• Reduced Regulatory Hurdles– Dynamic ability to modify if Interference is produced– Use of “Real” not worst-case Interference Models

• Transparently Share Spectrum– Frequency, Location (improve on current methods)– Time– Azimuth– Polarization


Time Usage Profile


Radio Spectrum Environment

UHF Broadcaster

Ku-Band Satellite

C-Band Satellite

Terrestrial Microwave

Radio Navigation

Passive Radio Astronomy

Mobile Services

Satellite


Frequency Agile Radio System


Spectrum Engineer Lab Projects

• Current– Spectrum Usage Measurements

• Interference to Passive Users– Spectrum Occupancy Modeling

• Future– Anthropogenic Noise Study

• “Interference Temperature”– Frequency Agile Radio

• Simulation Software• Hardware Prototype


Spectrum Study Data Set

• In Process of Being Made Licensable– Contact Me for Data

• www.measuredspectrum.com• [email protected]


Conclusion

• Spectrum From 400 MHz to 7.2 GHz is Being Used

• More Work Needs to be Done in this Long Neglected Area

Supported by the National Science Foundation, AST-0309469

Documents

Radio Spectrum Engineering - nsma.org