C-Guide to CDMA Network Interference Test-20070526-A-2.0

8/13/2019 C-Guide to CDMA Network Interference Test-20070526-A-2.0

1/43

Document No. Product Name

Intended Users Huawei engineers Product Version

Writing Dept. Techincal SupportDepartment

Document Version 2.0

Guide to CDMA Network InterferenceTest

or Interna! Use "n!#

Prepared $# Wang Jianyong Date 2007.03

%e&iewed $# Date

%e&iewed $# Date

Appro&ed $# Date

'uawei Tec(no!ogies Co.) *td.

A!! %ig(ts %eser&ed


2/43

Guide to D!" #etwor$ %nter&erence Test 'or internal use

%e&ision %ecords

Date %e&ision Version Description Aut(or

200(.0) *.0 'irst dra&t Tan +ang,o

2007.03 2.0 !odi&ied Wang Jianyong

Huawei Technologies -roprietary -age 2 o& 3


3/43


Contents

+ "&er&iew..................................................................................................................................... ,

*.* %mpact and lassi&ication o& %nter&erence.......................................................................... /

*.2 alculation o& %nter&erence .............................................................................................../

- Interference Test !owc(art .....................................................................................................

/ Interference Test Met(od ......................................................................................................... 0

3.* %ntroduction to +T2(0..................................................................................................... )

3.*.* 1ey %ndices............................................................................................................. )

3.*.2 peration !ethod................................................................................................. **

3.*.3 %nter&erence Test................................................................................................... *)

3.*. 4porting the Test Data .......................................................................................2*

3.*.( Sa5ing the Test Settings....................................................................................... 22

3.2 6e5erse %nter&erence Test............................................................................................... 22

3.2.* TS30/*............................................................................................................ 22

3.2.2 TS3/0/ .............................................................................................................. 2

3.2.3 TS3/*2 .............................................................................................................. 2(

3.2. -recautions...........................................................................................................2/3.3 'orward %nter&erence Test............................................................................................... 2)

3.3.* %nter&erence o& the 4ternal %nter&erence Source on the D!" Signal.................2)

3.3.2 %nter&erence o& the D!" 'orward Signal on "nother System.............................2

3. ther %ssues &or "ttention in the %nter&erence Test.......................................................... 2

3..* Tester8Speci&ic -ro,lem ...................................................................................... 2

3..2 %n&ormation ollection ..........................................................................................2

1 Co!!ection of Interference 2pectrums.................................................................................... /3

.* 6e5erse road,and %nter&erence &rom 6epeaters...........................................................3*

.2 %nter&erence &rom T9 "cti5e utdoor "ntenna ...............................................................32

.3 %nter&erence aused ,y Signal :ea$age o& a,le T9 "mpli&ier ......................................3

. %nter&erence &rom the omputer Jammer ....................................................................... 3/

.( %nter&erence &rom the Wal$ie8Tal$ie................................................................................37

./ %nter&erence &rom the #eon :ight .................................................................................... 3)

.7 %nter&erence &rom the TS(0 "nalog ommunication System .....................................3

4 56amp!es of Interference Test ............................................................................................... 1-

(.* 6"S+S &&ice %nter8!odulation -ro,lem ....................................................................... 2

(.2 Wal$ie8Tal$ie %nter&erence Test in Heyuan ity.............................................................. 3

(.3 T9 Station %nter&erence Test .......................................................................................... 3



4/43


(. T9 hannel Supplementer %nter&erence Test..................................................................3

(.( TS(0 %nter&erence Test .............................................................................................. 3

Huawei Technologies -roprietary -age o& 3


5/43


7e#words

D!"; 6W; span; dynamic range; re&erence le5el; trap &ilter

A$stractuality. %t also a&&ects the call >uality;

call drop; hando&&; con5ersation >uality; networ$ co5erage; and capacity. How to

reduce or eliminate the inter&erence is an important tas$ o& radio networ$ planning

and optimi?ation. This document pro5ides a systematic description a,out the

inter&erence test methods.

D!" inter&erence ,asically consists o& e4ternal inter&erence and non8e4ternal

inter&erence.

4ternal inter&erence comes &rom the repeater; radar; analog TS @such as the

TS(0 and "!-SA; T9 station; wal$ie8tal$ie; con&erence inter&erence system;

T9 acti5e recei5er; and other communication e>uipment.

#on8e4ternal inter&erence comes &rom the sel&8inter&erence o& the system; illegal

terminals; parameter setting pro,lems; and &aults o& TS e>uipment.

!eanwhile; D!" inter&erence includes &orward inter&erence and re5erseinter&erence.

6e5erse inter&erence ,rings the &ollowing impacts on the systemuency at 3/0

degrees in the open s$y.

-er&orm directional tests at

three di&&erent places. The

intersection o& directions

tested at three places is the

location o& the inter&erence

source. "lternati5ely; dri5e

the 5ehicle around the TS to

test the location o& the

inter&erence source.

nd

Swap the main and di5ersity

Gumpers on top o& the

ca,inet. hec$ whether the

6SS%s o& the main and

di5ersity are also swapped.

%& the strengths o&

inter&erence on the main

and di5ersity are

inconsistent; chec$

whether the TS is

connected with repeaters.

%t can ,e

determined

that the

component

on the TS

6' channel;

the T6F,oard; or

antenna is

&aulty; or

the Gumper

connections

are wrong.

Does &orward

inter&erence

e4istE

Stop the T6F. onnect the +T2(0 to

the +agi antenna and test the &orward

inter&erence in the open s$y. @%t is

recommended to add the &ilter in the test

to ensure a su&&icient dynamic range.A

+

#

#

#

+

#

+

+

#

+

#

+

"re 6SS%s o& ,oth the

main and di5ersity

higher than 87( dmE

onnect the +T2(0 to the

antenna &eeder connector on top

o& the ca,inet. hec$ whether

the noise &loor is greater than 8

7( dm.

%s the 6SS% o& the

T6F greater than 87(

dmE @Tra&&ic

measurement or :!T

tracingA

Sweep the &re>uency at 3/0

degrees in the open s$y.

-er&orm directional tests at

three di&&erent places. The

intersection o& directions

tested at three places is the

location o& the inter&erence

source. "lternati5ely; dri5e

the 5ehicle around the TS to

test the location o& the

inter&erence source.

nd

Swap the main and di5ersity

Gumpers on top o& the

ca,inet. hec$ whether the

6SS%s o& the main and

di5ersity are also swapped.

%& the strengths o&

inter&erence on the main

and di5ersity are

inconsistent; chec$

whether the TS is

connected with repeaters.

%t can ,e

determined

that the

component

on the TS

6' channel;

the T6F,oard; or

antenna is

&aulty; or

the Gumper

connections

are wrong.

Does &orward

inter&erence

e4istE

Stop the T6F. onnect the +T2(0 to

the +agi antenna and test the &orward

inter&erence in the open s$y. @%t is

recommended to add the &ilter in the test

to ensure a su&&icient dynamic range.A

igure +.+ %nter&erence test &lowchart



8/43


/ Interference Test Met(od

D!" networ$ &orward=re5erse recei5ers ha5e lower power spectrum o& input signal

and are sensiti5e o& the electromagnetism en5ironment. The detection capacity o&

wea$ signal is an important criterion &or the selection o& inter&erence tester. To

e&&ecti5ely test the &orward=re5erse inter&erence; the inter&erence testers must ha5e

the capa,ility o& detecting at least 8*23 dm=30 1H?signal.

urrently; among the testers used ,y Huawei; +T2(0 supplied ,y the Te$troni4

meets the a,o5e re>uirements. +T2(0 is recommended &or the &ield test. %& the

+T2(0 is una5aila,le; "gilent7(; H-)(/* series tester; H-)20 tester; or

TS(0 electrical tester is optional.

!ost Huawei regional di5isions and representati5e o&&ices ha5e the +T2(0; so this

section introduces the usage o& +T2(0 only.

/.+ Introduction to 89T-43

/.+.+ 7e# Indices

+. 2ensiti&it#

Generally; the recei5er sensiti5ity o& the spectrum analy?er is de&ined as the minimum

recei5ed le5el o& the signal ,andwidth * H?. %& the signal ,andwidth is 4 H?; the

recei5er sensiti5ity is calculated as &ollowsuency

num,er in the C(anne!or reuency in the re


14/43


igure +.+ perations on the +T2(0 &unctional window @*A

2A Tap the ,utton la,eled as -on the right o& the main inter&ace to display the

power spectrum test inter&ace. Then select 2pectrum.

Huawei Technologies -roprietary -age * o& 3


15/43


igure -.+ perations on the +T2(0 &unctional window @2A

3A n the Spectrum inter&ace; select %ef *e&e!> ???d9mand enter the re&erencele5el @&or e4ample; 80A in the 5alue input ,o4 on the right o& the inter&ace. n the

precondition that the tester does not generate the Input o&errange alarm;

reduce the re&erence le5el as much as possi,le.

A Tap 2PAN>???d9mand enter the range o& span in the 5alue input ,o4 on the

right o& the inter&ace. During the test; i& you want to sa5e the current screen @&or

e4ample; when the inter&erence is detectedA; manual operation is re>uired. Two

sa5ing methods are a5aila,le. Generally; to meet the re>uirement o& writing a

report and ma$e the layout more pleasing; the &irst method is recommended to

sa5e the data.

(A Select the i!e 56port 2creen asmenu to display the 2a&e asdialog ,o4. n

this dialog ,o4; enter the &ile name and storage location @uilt%nDis$ or ':"SH

cardA to record the spectrum in the &orm o& screen copy.

/A Select the i!e 56port Trace asmenu to display the 2a&e asdialog ,o4. nter

the &ile name and storage location @uilt%nDis$ or ':"SH cardA to record the

spectrum in the &orm o& te4t.

Huawei Technologies -roprietary -age *( o& 3


16/43


igure ,.+ perations on the +T2(0 &unctional window @3A

Spectrogram window*A Display the test main inter&ace o& the +T2(0. n the drop8down menu at the

upper le&t corner; select the system to ,e used and then enter the &re>uency

num,er in the C(anne!or re ???d9m and enter the

re&erence le5el in the 5alue input ,o4 on the right o& the inter&ace. n the

precondition that the tester does not generate the Input o&errange alarm;

reduce the re&erence le5el as much as possi,le.

A Tap 2PAN>???d9mand enter the span in the 5alue input ,o4 on the right o& the

inter&ace.

(A Select the 2pectrogramta, to display the time8&re>uency spectrum. During the

test; i& you want to sa5e the test data; use either o& the &ollowing methoduency

num,er in the C(anne!or re


18/43


igure -.+ perations on the +T2(0 &unctional window @(A

/.+./ Interference Test

Tap the inter&erence test ,utton @la,eled as /A. "t the le&t upper corner; there are &our

,uttons corresponding to &our display modes. These &our modes are Identif#;

2trengt(; Audio Demod; and Noise; as shown in 'igure *.*. Generally; only

Identif#; 2trengt(; and Noiseare used.

Huawei Technologies -roprietary -age *) o& 3


19/43


igure +.+ Test results displayed in %denti&y mode

+. Met(od for Identif#ing t(e Interference 2igna!

To identi&y the inter&erence signal; per&orm the &ollowing stepsuency

to the central &re>uency o& the inter&erence signal.

3A ,ser5e the lower le&t corner o& the display area. "ll the possi,le signal

standards that match the central &re>uency o& the inter&erence signal are

displayed in this area.A Tap Measureand e4ecute the matching &unction. %& matched records are &ound;

the results will ,e displayed on the lower right corner o& the display area.

-. Met(od for *ocating t(e Interference 2igna!

To locate the inter&erence signal; per&orm the &ollowing stepsual to 0d.

/.-.+ 9T2/3,+C

'igure *.*shows TS3/0* 6' &ront8end module @!'!A.



23/43


Test portTest port

igure +.+ -orts on the !'! o& the TS3/0* @schematic drawingA

64 main test port

T4 test port

64 di5ersity test port

64 main test port

T4 test port

64 di5ersity test port

igure +.- -orts on the !'! o& the TS3/0* @photoA



24/43


During the re5erse inter&erence test; connect the +T2(0 to the 6FD8Test* port.

+ou can also connect the +T2(0 to the 6FD8Test2 port. The dynamic inde4 o& the+T2(0; howe5er; is a&&ected; ,ecause part o& the power lea$s out &rom the

transmission channel and goes to the recei5ing channel. There&ore; the result is

inaccurate.

%n addition;'igure *.*shows that the :#" and *=2 power splitter are a5aila,le on the

recei5ing channel. The gain o&&sets the power loss; so the test result directly re&lects

the 6SS% in real en5ironment.

/.-.- 9T2/,3,

'igure *.*shows the ports on the DDI o& the TS3/0/.

igure +.+ -orts on the DDI o& the TS3/0/ @schematic drawingA



25/43


Test port

Top of t(e CDDU

Test port

Top of t(e CDDU

igure +.- -orts on the DDI o& the TS3/0/ @photoA

During the re5erse inter&erence test; connect the +T2(0 to the 6F* port anddisconnect the 6F2 port.

/.-./ 9T2/,+-

'igure *.*shows the 6:DI panel o& the TS3/*2.

igure +.+ 6:DI panel o& the TS3/*2 @schematic drawingA

Huawei Technologies -roprietary -age 2( o& 3


26/43


Test portTest port

igure +.- 6:DI panel o& the TS3/*2 @photoA

During the re5erse inter&erence test; connect the +T2(0 to 6F"D8TST and 6FD8TST respecti5ely; and chec$ the test results.

%& the test results at two ports are less than 4 d9m @K( dm 20 d;

wherein; 20 d is the 6:DI gain; and K( dm is thermal noiseA; the

inter&erence does not e4ist.

%& the results at two ports are di&&erent @one is greater than K( dm; ,ut the

other is close to K( dmA; the inter&erence does not e4ist.

%& the two results at two ports are greater thanK7(dm; the inter&erence e4ists.

/.-.1 Precautions

The re5erse inter&erence test should ,e per&ormed ,ased on the networ$ acti5ation

and num,er allocation status. %& the system is ust put into ser5ice; the system load is

5ery load. With the increase o& num,ers allocated; the system load increases

gradually. "t this time; you are recommended to per&orm the re5erse inter&erence test

when the system load is low.

%& the test is per&ormed during the daytime when the system load is high; the

inter&erence caused ,y su,scri,ers themsel5es in the sector must ,e e4cluded &rom

the test result. 'or e4ample; 3 d must ,e deducted &rom the test result in a system

Huawei Technologies -roprietary -age 2/ o& 3


27/43


loaded with (0L capacity.

Generally; reser5es ,road,and inter&erence is rare. %& such inter&erence is detectedduring the test; try to lower the TS power and test whether the reser5e ,road,and

inter&erence comes &rom the tester itsel&. %& the re5erse ,road,and inter&erence is

reduced a&ter the TS transmit power is lowered; it can ,e concluded that the

inter&erence comes &rom the tester itsel&.

This document analy?es the inter&erence test o& re5erse narrow ,and @,andwidth is

less than *.223 !H?A only.

When the re5erse narrow,and inter&erence e4ists on the system; adust the span o&

the +T2(0 to &ind the inter&erence &re>uency and amplitude.

%& the +T2(0 is used to test the inter&erence o& a networ$; set the span to *0 !H?;

and 6W to *00 $H?. The test result is " dm=*00$H?. ecause the result amplitude

is higher; re5erse narrow,and inter&erence is co5ered ,y the thermal noise. %n this

case; lower the span to ( !H?; and 6W to 30 $H?. Then; the result is

"*0Clg@30$H? = *00$H?AB@"K(.23Adm = 30$H?. %& the re5erse narrow,and

inter&erence is strong; the inter&erence can ,e displayed on the +T2(0.

%& the re5erse narrow,and inter&erence still cannot ,e displayed on the +T2(0; lower

the span again; and adust the 6W to *0 $H?. Then; the result is " *0Clg@*0$H? =

*00$H?AB@"K*0Adm =*0$H?. ased on the result displayed on the +T2(0; udgewhether the re5erse narrow,and inter&erence e4ists; or adust the span and reduce

the 6W again.

T(e purpose of adusting t(e %9W is to re&ea! t(e re&erse narrow$and

interference (idden $# t(e t(erma! noise.

%& multiple re5erse narrow,and inter&erences are detected ,y the +T2(0; o5erlap the

inter&erences to o,tain the total energy o& re5erse inter&erence. %n this way; you can

$now the total energy o& in,and re5erse inter&erences. The &ollowing descri,es how to

calculate the total energy o& in,and re5erse inter&erence in di&&erent casesuipment

-laces where there are &actories that may cause inter&erence; such as the iron wor$s;

cement mill; and gal5ani?ation &actory. To collect the in&ormation; you must &re>uently

communicate with the customer; as$ the people li5ing or wor$ing around the site; and

chec$ whether there are companies or indi5iduals that may use the wireless

communication system or de5ices that may cause inter&erence. This can impro5e the

wor$ e&&iciency in locating the inter&erence source.

1 Co!!ection of Interference 2pectrums

There are many types o& inter&erence. 'ailure to $now the spectrum o& each type o&

inter&erence will a&&ect accurate location o& the inter&erence source. This section

pro5ides the &re>uently8seen inter&erence spectrums to help you &ind out the

inter&erence source as soon as possi,le.



31/43


1.+ %e&erse 9road$and Interference from %epeaters

igure +.+ Spectrum o& the re5erse ,road,and inter&erence &rom repeaters

Huawei Technologies -roprietary -age 3* o& 3


32/43


1.- Interference from TV Acti&e "utdoor Antenna

igure +.+ Spectrum o& the inter&erence &rom the outdoor acti5e T9 antenna @*A



33/43


igure +.- Spectrum o& the inter&erence &rom the outdoor acti5e T9 antenna @2A



34/43


1./ Interference Caused $# 2igna! *eakage of Ca$!e TVAmp!ifier

igure +.+ Spectrum o& the inter&erence caused ,y signal lea$age o& ca,le T9

ampli&ier @*A



35/43


igure +.- Spectrum o& the inter&erence caused ,y signal lea$age o& ca,le T9

ampli&ier @2A

Huawei Technologies -roprietary -age 3( o& 3


36/43


1.1 Interference from t(e Computer Eammer

igure +.+ Spectrum o& the inter&erence &rom the computer ammer

Huawei Technologies -roprietary -age 3/ o& 3


37/43


1.4 Interference from t(e Wa!kie=Ta!kie

igure +.+ Spectrum o& the inter&erence &rom the wal$ie8tal$ie



38/43


1., Interference from t(e Neon *ig(t

igure +.+ Spectrum o& the inter&erence &rom the neon light

Huawei Technologies -roprietary -age 3) o& 3


39/43


1. Interference from t(e 5T2143 Ana!og Communication2#stem

igure +.+ Spectrum o& the inter&erence &rom the TS(0 analog communication

system @*A



40/43


41/43


igure +./ Spectrum o& the inter&erence &rom the TS(0 analog communication

system @3A

Huawei Technologies -roprietary -age * o& 3


42/43


igure +.1 Spectrum o& the inter&erence &rom the TS(0 analog communication

system @A

4 56amp!es of Interference Test

4.+ %A282 "ffice Inter=Modu!ation Pro$!em

RASYS BTSI nter-Modul at i on



43/43

Date post:	04-Jun-2018
Category:	Documents
Upload:	jackson-a-plus
View:	218 times
Download:	0 times

C-Guide to CDMA Network Interference Test-20070526-A-2.0

Documents