Interference at Cellular Systems Gunawan W 29052013

7/27/2019 Interference at Cellular Systems Gunawan W 29052013

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Interference at Cellular Systems

Gunawan Wibisono



Agenda

• Cellular Technology

• Frequency Spectrum

•

Interferences• Interference Mitigation



Cellular Technology



Cellular Technology





Cellular Technology



Cellular Technology



Frequency Spectrum



Nov-11-2003IEEE 802.20 Contribution # C802.20-03-99

9

ITU-R Reference Documents

[1] Recommendation M.1455: “KEYCHARACTERISTICS FOR THE INTERNATIONAL MOBILETELECOMMUNICATIONS-2000 (IMT-2000) RADIO

INTERFACES”

[2] Recommendation SM.329-7: “SPURIOUS

EMISSIONS”

[3] Recommendation M.1225: “GUIDELINESFOR EVALUATION OF RADIO TRANSMISSIONTECHNOLOGIES FOR IMT-2000”




10

ITU-R IMT-2000’s Key Characteristics

The IMT-2000 3G Radio TransmissionTechnologies (RTT) evaluation processrequired data on key RF characteristics.

They were defined in ITU-RRecommendation. M.1455 [1]

The key RF characteristics that determine

a radio’s coexistence performance arehighlighted below (in the next slide)




11

Coexistence-Affecting Key RF

Performance Characteristics (1/2)

Radio Transmitter:

Transmit power & emission mask ACLR*

Spurious Emissions

Frequency Accuracy & Stability

* ACLR = Adjacent Channel Leakage (power) Ratio




12

Coexistence-Affecting Key RF

Performance Characteristics (2/2)

Radio Receiver:

Sensitivity Intermodulation sensitivity

Blocking

Spurious response

Selectivity




13

Transmitter Characteristics (1/5)

3.3.1 Emission Mask

The maximum transmit power and emission maskshould be stated (for both MS and BS).

If the proposed radio technology supports several power classes, they should be specified as well.

Test results and a statement on the specifiedemission mask(s) are required.




14


3.3.2 ACLR

ACLR is defined as the attenuation of the transmit

power which is“spilled

”into the adjacent channels(due to filtering imperfections).

It is measured relative to the carrier signal power and expressed as dBc attenuation values.

ACLR is a function of the frequency offset from the

assigned channel frequency.

Test results and a statement on the specified ACLR are required.




15


3.3.3 Spurious Emissions

ITU-R Recommendation M.329-7 [2] defines

spurious emissions as “Emission on a frequency, or frequencies, which are outside the necessarybandwidth and the level of which may be reducedwithout affecting the corresponding transmission of information.Spurious emissions include harmonic emissions,parasitic emissions, intermodulation products andfrequency conversion products but exclude out-of-band emissions.”




16


3.3.3 Spurious Emissions (cont’d)

Spurious emissions are generated by non-linear

components in the transmitter in the process of carrier signal generation, mixing, modulation andamplification.

Test results and a statement on the specifiedperformance levels for each type of spuriousemission are required.




17


3.3.4 Frequency Accuracy and Stability

Frequency accuracy is expressed in PPM (parts per

million) and is a measure of the frequency deviationfrom the assigned carrier frequency.

Frequency stability is a measure of this deviation thatis caused by operational time-varying factors such astemperature, humidity etc.

Test results and a statement on the specifiedfrequency accuracy and stability are required.




18

Receiver Characteristics (1/5)

3.3.5 Receiver Sensitivity

Reference [1] defines receiver sensitivity as the

minimum power, measured at the antenna port, atwhich the frame error rate (FER) or bit error rate(BER) are below a certain specified limit.

Sensitivity is a function of the information bit rate,Eb/No, temperature and the receiver noise-figure(NF).

Test results and a statement on the specifiedreceiver sensitivity levels are required.




19


3.3.6 Intermodulation Sensitivity

Defined as the levels of out-of-band interferingsignals that when mixed in the receiver front-end,produce an in-band third order non-linearity product.

Test results and a statement on the specified

receiver intermodulation sensitivity levels arerequired.




20


3.3.7 Receiver Blocking

Receiver blocking is the effect of a strong out-of-

band signal, present at the input of the receiver, onthe receiver ’s ability to detect an in-band wantedsignal.

The blocking signal reduces the specified receiver sensitivity by a certain number of dB's.

Test results and a statement on the specifiedreceiver blocking performance levels are required.




21


3.3.8 Spurious Response

Spurious response in a receiver occurs when

unwanted signals, having frequencies other than thetuned frequency, produce a receiver output as if theywere wanted signals.

Spurious response is specified in terms of thefrequencies and signal levels that produce suchunwanted receiver output.

Test results and a statement on the specified receiver spurious response performance are required.




22


3.3.9 Selectivity

Receiver selectivity is a measure of the receiver ’s

ability to reject signals from adjacent channels whilereceiving a wanted signal on its tuned frequency.

Selectivity is specified as the ratio (in dB) of theadjacent channel signal level to the assigned channelsignal level in which a reference BER/FER ismaintained.

Test results and a statement on the specified receiver selectivity performance are required.



30 Mar. –

1 Apr. 2004 Skopje Measurement of Frequency, Field Strengthand Power Flux Density © ADP

23

Measurement sites

Fixed installations. A suitable site for a fixed installation isone where the fields of the emissions to be recorded will be relatively undisturbed by local structures or terrainfeatures. Fixed sites are primarily used for measurementsat low frequencies (typically less than 30 MHz).

Mobile installations comprise of field strength measuringequipment housed in a monitoring vehicle. Their advantage compared to fixed installations is that they canobserve both the space and time distribution of fieldstrength. This property is particularly useful in the contextof VHF/UHF field-strength measurements, where

measurements need to be taken at variable heights. Nevertheless, due to the propagation characteristics inthese bands, the antenna has to be adjusted to the directionand polarization of the received signal.



30 Mar. –

1 Apr. 2004 Skopje Measurement of Frequency, Field Strengthand Power Flux Density © ADP

24

Requirements for antennas

For frequencies below 30 MHz a vertical rod or wire antenna with anoverall vertical length of not more than 0.1λ at the frequency of interest, together with a counter poise is recommended. ITU-R SM.378and P.845 provide instructions for the successful deployment of theseantennas.

In the frequency range between 30 MHz and 1000 MHz, a widebanddipole or a directional antenna such as a dipole installed in a corner-

reflector or a parabolic reflector is recommended. It should be erectedat sufficient height above the ground, e.g. 10 m, and with appropriateorientation for the azimuth of signal arrival and polarization. Where awide band of frequencies must be measured, a log-periodic antenna isrecommended.

For frequencies greater than 1 GHz, the antenna gain becomes an

increasingly important factor, because of the small effective apertureand the high cable or waveguide loss. Thus, the installation of a hornor log-periodic antenna in a parabolic reflector or another wide-aperture collector is recommended. High gain antennas should also beadjustable for maximum signal pick-up of the wanted emission.



30 Mar. –

1 Apr. 2004 Skopje Measurement of Frequency, Field Strengthand Power Flux Density © ADP 25

Measurements along a route

Influenced by the local receiving conditions, the true values of the fieldstrength can significantly differ from the predicted ones. It is thereforenecessary they are verified by measurements in order to determine theradio coverage of a large area.

All measurements must be recorded along with their geographical co-ordinate data for locating the points of measurements and for mappingthe results that were gathered on the most accessible roads of the area

in question. Digital network systems (such as GSM, DCS1800, UMTS, or DAB)

are sensitive to the effects of reflected reception. In this case, besidesmeasuring the signal level, the reception quality measurement, made

by the measurement of the bit-error ratio (BER) or channel impulseresponse (CIR) measurement, is also necessary to evaluate the system

performance. Using special monitoring equipment which automaticallygenerates calls, these measurements can be made on operational digitalnetworks without any adverse effect.



30 Mar. –

1 Apr. 2004 Skopje Measurement of Frequency, Field Strengthand Power Flux Density © ADP26

Mobile field measurements Due to the effect of reflected signals, the field strength along a route

shows severe fluctuation. Reproducible field strength test results can be calculated from a large

number of raw data readings, by fitting the data to statisticaldistributions. The number of sample points should be sufficient toreveal the statistics of long-term fading and the sampling frequencysufficiently high to determine the statistics of short-term fading of theelectric field strength.

For obtaining 1 dB confidence margin around the true mean value,field strength samples should be taken every 0.8, over a 40 longaveraging interval (50 measured values within distance of 40wavelengths).

Furthermore, the velocity of the monitoring vehicle must obey thefollowing relation:

where T r is the shortest time period required for the receiver to repeat

the measurement at a single frequency.

864[km/h][MHz] [s]r

v f T



30 Mar. –

1 Apr. 2004 Skopje Measurement of Frequency, Field Strengthand Power Flux Density © ADP27

Coordination data

A European cooperation agreement (Vienna Agreement of June 30, 2000 on frequencycoordination) has among others stated the following measurement procedure in cases of disagreement concerning the results of evaluation related to a specific coordinationrequest, to facilitate the enhancement of existing networks and in cases of harmfulinterference between stations in border regions in the VHF/UHF ranges. Results of field-strength measurements shall be exchanged, and therefore the measurement procedures have been standardized.

Measurement sites shall be selected so that there are no reflecting objects or as few as possible within ten times the wavelength (10). Visual contact with the transmittingantenna should exist where possible.

Depending on the conditions of measurement different records of the measurementincluding the setup must be made, so that the results are reproducible. The wholeequipment shall be specified.

In cases of fixed point measurement the height of the measurement antenna(s),measured from the ground, has to be varied between three and ten meters. Within thisrange the highest field strength value shall be recorded, as well as the height of the

antenna where this value was measured. This value has to be regarded as being a fieldstrength value at a height of ten meters.

A record of every measurement setup and every measurement must be stored in a data base. All data relevant to explain the measurement results have to be recorded for later calculations.



Departemen Komunikasi dan Informatika

MOBILE OPERATORS IN INDONESIA(FDD / Paired Band)

21/10/2013 DG POSTEL

Notes:

Reference: Number of subscribers: Annual report of operators year 2008, Ditjen

Postel.28

Telkomsel Indosat XL Axiata Hutch CPT Axis

Starting of operation

1995 1994 1996 2004 2004

Number of subs (end of

2008)

65,300,000 36,500,000 26,000,000 4,501,000 3,000,000

Standard GSM/UMTS /HSPA

GSM/UMTS /HSPA

GSM/UMTS /HSPA

GSM/UMTS /HSPA

GSM/UMTS /HSPA

Frequency

Band (MHz)

900/1800/

2100

900/1800/

2100

900/1800/

2100

900/1800/

2100

900/1800/

2100Bandwidth 40 MHz FDD 40 MHz FDD 20 MHz FDD 15 MHz FDD 20 MHz FDD




BAND PLAN GSM-900/1800


BAND PLAN GSM-900

ISAT TSEL

890 900 MHz

Uplink Downlink

907.5 915

XL ISAT TSEL XL

935 945 952.5 960

BAND PLAN GSM-1800

1745

XL ISAT TSEL NTS TSEL ISAT HCPCTSEL

1710 1717.5 1722.5 1730 1750 1765 1775 1785 MHz

1805 1812.5 1817.5 1825 1845 1860 1870 18801840 MHz

Uplink

Downlink

29




IMT-2000 (UMTS) BAND PLAN


BAND PLAN IMT-2000 (UMTS)

1955

Hutch

CPT AXIS TSEL INDOSAT

1920 MHz

2110 2145 MHz

1925

2115

1930

2120

1935

2125

1940

2130

XL

1945

2135

1950

2140

1965

2155

1960

2150

1975

2165

1970

2160

1985

2175

1980

2170

PCS-1900 DL

1990

2180

2000

2180

2010

2200

IMT Satellite ComponentGuard

band

30




MOBILE AND FWA OPERATORS ININDONESIA

(FDD / Paired Band)


Notes:• Bakrie Esia: 4 carrier 1.23 MHz di West Java, DKI, Banten,

• Telkom: 4 carrier 1.23 MHz exclude West Java, DKI, Banten

• Reference: Number of subscribers: Annual report of operators year 2008, Ditjen Postel.

31

SAMPOERNA TI

MOBILE-8

BAKRIETELECOM

TELKOMFLEXI

INDOSATSTARONE

SMART

Starting of operation

1985 1990s 1990s 2002 2002 2004

Number of subs(Y:2008)

N/A 3,004,400 7,300,000 12,725,000 761,589 N/A

Standard CDMA CDMA CDMA CDMA CDMA CDMA

FrequencyBand (MHz)

450 850 850 850 850 1900

Bandwidth 3.69 MHzFDD

4.92 MHzFDD

4.92 MHzFDD

4.96 MHzFDD

2.26 MHzFDD

6.15 MHzFDD

D K ik i d I f ik




BAND PLAN CDMA-850


BAND PLAN CDMA-850

37 78 119

835

Sub Band ex AMPS-A

160 201 242 283 384 425 466

880

507 548 589 630

Sub Band ex AMPS-B

835

890

BAKRIE TELKOMRsv MOBILE-8 Rsv ISAT

Wilayah Layanan: Jakarta, Banten dan Jawa Barat

TELKOM BAKRIERsv MOBILE-8 Rsv ISAT

Wilayah Layanan: Nasional, selain Jakarta, Banten dan Jawa Barat

Uplink Downlink

Tiap raster channel AMPS 30 kHz, 1 kanal CDMA = 41 kanal AMPS = 1.23 MHz

MHz

MHz

1019

32



Interferences at Cellular Technology

• CDMA BTS Tx interfering WCDMA Rx

• CDMA MS Tx interfering WCDMA Rx

• CDMA MS Tx interfering WCDMA UE Rx

• CDMA BTS Tx interfering WCDMA UE Rx

• WCDMA Tx interfering CDMA BTS Rx

•WCDMA UE Tx interfering CDMA BTS Rx

• GSM/WCDMA UE Tx interfering CDMA MS Rx

• GSM/WCDMA UE Tx interfering CDMA MS Rx



Interference

• To evaluate interference implications

– Qualitative method

direct implication into devices

– Quantitative method

• Simulation (many application tool can be used)

• Monitoring/Drive test



Interference

• Interfering at 900 MHz



Interference

• Interfering at 1900 MHz



Interference

• Interference from adjacent channel are

– Out of band emission (OOBE)

– Adjacent channel selectivity (ACS)



Interference



Interference





Co-Exist Spectrum



Co-Exist Spectrum





Co-Exist Spectrum



Co-Exist Spectrum



Co-Exist Spectrum





Closing

• Co-exist spectrum for two systems is allowed,

if the rejection spectrum is satisfied the

minimum requirement

• Some methods to get the minimum rejection

requirement are power amplifier, filter, and

antenna isolation

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