HUAWEI TECHNOLOGIES CO., LTD.
Huawei Confidential
Internal
www.huawei.com
Spectrum Test and Instructions for YBT250
ISSUE1.0
Page 2HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
The WCDMA system is a restricted communication system by the interference. The network quality, capacity and coverage are all related to the background noise.
When design the radio network, we must obtain the strength of the background noise in the coverage area.
If strong interference exists within the band, spectrum test need to be performed, or the operator have to apply for new frequency spectrum.
Page 3HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
After studying this course, you should be
able to:
Know the sources of electromagnetic
background interference.
Master the methods for electromagnetic
background test.
Know how to use YBT250 for spectrum
test.
Page 4HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 1 Impact of Electromagnetic Interference on the System
Chapter 2 Sources of Electromagnetic Background Interference
Chapter 3 Introduction to Interference Test Tools
Chapter 4 Methods for Electromagnetic Background Test
Chapter 5 Instructions for YBT250
Page 5HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 1 Impact of Electromagnetic Interference on the System
1.1 Bands Used in the WCDMA System
1.2 Interference Requirements for UE Reception
1.3 Interference Requirements for NodeB Reception
Page 6HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Bands used in the WCDMA system
Operating Band
UpLink BandUE transmit, Node B
receive
DownLink BandUE receive, Node B
transmit
I 1920 - 1980 MHz 2110 -2170 MHz
II 1850 -1910 MHz 1930 -1990 MHz
III 1710-1785 MHz 1805-1880 MHz
IV 1710-1755 MHz 2110-2155 MHz
V 824 - 849MHz 869-894MHz
VI 830-840 MHz 875-885 MHz
VII 2500 - 2570 MHz 2620 - 2690 MHz
VIII 880 - 915 MHz 925 - 960 MHz
IX 1749.9 - 1784.9 MHz 1844.9 - 1879.9 MHz
Band I, II, V and VII are most popular used in the world.
Band I is used in China.
Page 7HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Impact of Electromagnetic Interference on the System Determine the impact of interference on the system according to experience, as
shown in the following table (for UE).
Interference Band
Interference Level Not Affecting
Receiver Sensitivity (With the Sensitivity Worsened by 0.1 dB)
Acceptable Interference Level
(With the Sensitivity Worsened by 3 dB)
Acceptable Interference Level
(With the Sensitivity Worsened by 6 dB)
Interference That Seriously Effects Equipment Indexes
Instead of Equipment Running, Lower Than the Maximum Signal Strength (-25 dBm) the UE Can
Receive by 10 dB
Protocol Requirement
2110-2170 MHz (co-frequency interference)
-117 dBm/ 3.84 MHz-101 dBm/ 3.84 MHz
-96 dBm/ 3.84 MHz -35 dBm/ 3.84 MHzThe required sensitivity is -107 dBm/ 3.84 MHz.
2095-2185 MHz (adjacent channel interference, deviated from the carrier by 5 MHz)
-82 dBm/ 3.84 MHz -66 dBm/ 3.84 MHz -61 dBm/ 3.84 MHz -16 dBm/ 3.84 MHz
-66 dBm/ 3.84 MHz (with the sensitivity worsened by 3 dB)
2095-2185 MHz (in-band blocking, deviated from the carrier by 10 MHz)
-72 dBm/ 3.84 MHz -56 dBm/ 3.84 MHz -51 dBm/ 3.84 MHz -6 dBm/ 3.84 MHz
-56 dBm/ 3.84 MHz (with the sensitivity worsened by 3 dB)
2095-2185 MHz (in-band blocking, deviated from the carrier by 15 MHz)
-60 dBm/ 3.84 MHz -44 dBm/ 3.84 MHz -39 dBm/ 3.84 MHz 6 dBm/ 3.84 MHz
-44 dBm/ 3.84 MHz (with the sensitivity worsened by 3 dB)
Other bands (out-of-band blocking and spurious response)
-60 dBm/ 3.84 MHz -44 dBm/ 3.84 MHz -39 dBm/ 3.84 MHz 6 dBm/ 3.84 MHz
-44 dBm/ 3.84 MHz (with the sensitivity worsened by 3 dB)
Note: dBm/Hz refers to the level unit of single-tone signals. The reference port for measurement is the reception port of the UE antenna. The reference requirements are based on the protocol TSG25.101.
Page 8HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Impact of Electromagnetic Interference on the System Determine the impact of interference on the system according to experience,
as shown in the following table (for NodeB).
Interference Band
Interference Level Not Affecting
Receiver Sensitivity (With the Sensitivity Worsened by 0.1 dB)
Acceptable Interference Level
(With the Sensitivity
Worsened by 3 dB)
Acceptable Interference Level
(With the Sensitivity
Worsened by 6 dB)
Interference That Seriously Effects Equipment Indexes
Instead of Equipment Running, Lower Than the Maximum
Signal Strength (-70 dBm) the UE Can Receive by 10 dB
Specification for NodeB Indexes
1920-1980 MHz (co-frequency interference)
-121 dBm/ 3.84 MHz -105 dBm/ 3.84 MHz-100 dBm/ 3.84 MHz
-80 dBm/ 3.8 4MHzThe sensitivity specification is -123 dBm/3.84MHz.
1900-2000 MHz (adjacent channel interference, deviated from the carrier by 5 MHz)
-63 dBm/ 3.84 MHz -47 dBm/ 3.84 MHz -42 dBm/ 3.84 MHz -22 dBm/ 3.84 MHz-42 dBm/ 3.84 MHz (with the sensitivity worsened by 6 dB)
1900-2000 MHz (in-band blocking)
-51 dBm/ 3.84 MHz -35 dBm/ 3.84 MHz -30 dBm/ 3.84 MHz -10 dBm/ 3.84 MHz-30 dBm/ 3.84 MHz (with the sensitivity worsened by 6 dB)
1900-2000 MHz (out-of-band blocking)
-46 dBm/ 3.84 MHz -30 dBm/ 3.84 MHz -25 dBm/ 3.84 MHz -5 dBm/ 3.84 MHz-25 dBm/ 3.84 MHz (with the sensitivity worsened by 6 dB)
935-960 MHz1805-1880 MHz (out-of-band blocking)
-5 dBm/Hz 11 dBm/Hz 16 dBm/Hz 36 dBm/Hz16 dBm/Hz (with the sensitivity worsened by 6 dB)
Other bands (out-of-band blocking)
-26 dBm/Hz -10 dBm/Hz -5 dBm/Hz 15 dBm/Hz-5 dBm/Hz (with the sensitivity worsened by 6 dB)
Note: dBm/Hz refers to the level unit of single-tone signals. The reference port for measurement is the reception port of the NodeB antenna. The reference requirements are based on the protocol TSG25.101. During analysis, the index for adjacent channel interference and in-band blocking is 10 dB better than that specified in the protocol. This is the RF index the NodeB
can ensure.
Page 9HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Impact of Electromagnetic Interference on the System
Interference requirements for UE reception (taking the band 2110 - 2170 MHz as an example) Interference band: 2110 - 2170 MHz
Interference level not affecting receiver sensitivity: -117 dBm/3.84 MHz, with the sensitivity worsened by 0.1 dB
Acceptable interference: -101 dBm/3.84 MHz, with the sensitivity worsened by 3 dB
Acceptable interference: -96 dBm/3.84 MHz, with the sensitivity worsened by 6 dB
Interference that seriously effects equipment indexes instead of equipment running:
-35dBm/3.84MHz, lower than the maximum signal strength (-25 dBm) the UE can receive by 10 dB
Sensitivity: at least -107 dBm/3.84 MHz as required in the protocol
Page 10HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Impact of Electromagnetic Interference on the System
Interference requirements for NodeB reception (taking the band 1920 -1980 MHz as example) Interference band: 1920 - 1980 MHz
Interference level not affecting receiver sensitivity: -121 dBm/3.84 MHz, with the sensitivity worsened by 0.1 dB
Acceptable interference: - 105 dBm/3.84 MHz, with the sensitivity worsened by 3 dB
Acceptable interference: - 100 dBm/3.84 MHz, with the sensitivity worsened by 6 dB
Interference that seriously effects equipment indexes instead of equipment running: -80 dBm/3.84MHz
Sensitivity: at least -123 dBm/3.84 MHz as required in the protocol
Page 11HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 1 Impact of Electromagnetic Interference on the System
Chapter 2 Sources of Electromagnetic Background Interference
Chapter 3 Introduction to Interference Test Tools
Chapter 4 Methods for Electromagnetic Background Test
Chapter 5 Instructions for YBT250
Page 12HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 2 Sources of Electromagnetic Background Interference
2.1 2G Band Allocation
2.2 Analysis on Interference Sources
Page 13HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
2G Band Allocation
In china, 2G bands are allocated as follows:
Band (MHz) Occupation
1710~1720/1805~1815 GSM1800 for China Mobile
1745~1755/1840~1850 GSM1800 for China Unicom
1800~1805 SCDMA (Beijing Xinwei)
1850~1865/1920~1945 Reserved
1865~1880/1954~1960 PCS1900 (not occupied)
1880~1900/1960~1980 FDD WIL (used by China Telecom and China Unicom in some cities by the end of 2002)
1900~1920 TDD WLL (PHS/DECT)
Planning of Bands 1.8 GHz and 1.9 GHz in China
Page 14HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 2 Sources of Electromagnetic Background
Interference
2.1 2G Band Allocation
2.2 Analysis on Interference Sources
− TDD WLL
− FDD WLL
− Microwave transmission
− Repeater
Page 15HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Analysis of Interference Sources
TDD WLL (PHS/DECT)
The system occupies the 1900 -1920 MHz band.
For the PHS system, the bandwidth occupied by the channel is
smaller than or equal to 288 KHz.
For the DECT system, the bandwidth occupied by the channel
is smaller than or equal to 1533 KHz.
FDD WLL
Uplink band: 1880 -1900 MHz
Downlink band: 1960 -1980 MHz
The bandwidth occupied by the system is 1.25 MHz.
The EiRP of a typical NodeB is about 25 dBm.
Page 16HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Analysis of Interference Sources
Microwave transmission Occupied bandwidth: usually over several MHz.
Normal reception level of microwave is about -60 dBm, imposing a great impact on the WCDMA system.
Repeater Nonstandard installation results in insufficient antenna isolation, thus self-
excitation. This affects normal running of the NodeB where the repeater is installed.
The repeater is a wide-band non-linear amplifier. Its intermodulation index exceeds the one specified in the protocol. The repeater easily causes
interference to nearby NodeBs when its power is too large.
Others Some communication devices occupy WCDM bands. Unreasonable installation
and isolation result in high harmonic signals and thus cause interference to the WCDMA system. In addition, radar is also a common interference source.
Page 17HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 1 Impact of Electromagnetic Interference on the System
Chapter 2 Sources of Electromagnetic Background Interference
Chapter 3 Introduction to Interference Test Tools
Chapter 4 Methods for Electromagnetic Background Test
Chapter 5 Instructions for YBT250
Page 18HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 3 Introduction to Interference Test Tools
1.1 Spectrum Analyzer
1.2 Antenna
1.3 Low Noise Amplifier
Page 19HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Interference Test Tools
Spectrum analyzer
A spectrum analyzer is used to test frequency domain features of signals, covering spectrum, adjacent channel power, fast time domain scanning, spurious radiation and intermodulation attenuation.
Key indexes
− Resolution bandwidth (RBW)
− Input frequency and central frequency (F0)
− Sensitivity
− Span
− Reference level (RefLvl)
− Video filter bandwidth (VBW)
− Input signal attenuation (ATT)
− Detection mode (RMS)
− Sweep time
Page 20HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Interference Test Tools
Main technical indexes of various spectrum analyzers
Model Working Band Sensitivity (1 Hz)Minimum Resolution
Bandwidth
HP8591E 30 - 1.8 GHz -145 dBm 30 Hz
HP8594E 30 - 2.9 GHz -142 dBm 30 Hz
HP8595E 30 - 6.5 GHz -142 dBm 30 Hz
HP8561E 30 - 6.5 GHz -145 dBm 1 Hz
YBT250 30 - 2500 MHz -132 dBm 1 KHz
Page 21HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Interference Test Tools
Antenna
Omnidirectional antenna: It facilitates interference
measurement instead of interference location.
Directional antenna: It is used to search interference sources.
The more distinct the directivity is and the higher the gain is,
the stronger the searching capability is.
Common directional antennas:
− Panel antenna
− Yagi antenna
− Log periodic antenna
Page 22HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Interference Test Tools
Low noise amplifier (LNA)
Used to improve the receiver sensitivity of the testing instrument.
During a test, we can select the LNA with 30 dB gain and 5 dB
noise coefficient.
Additional power supply needs to be considered for the LNA. Some
testing instruments (like YBT250 ) are configured a built-in LNA.
For a cascade network, the noise coefficient of the system depends
on level-1 noise coefficient when a high gain amplifier is configured
at the front end of the system.
Page 23HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 1 Impact of Electromagnetic Interference on the System
Chapter 2 Sources of Electromagnetic Background Interference
Chapter 3 Introduction to Interference Test Tools
Chapter 4 Methods for Electromagnetic Background Test
Chapter 5 Instructions for YBT250
Page 24HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 4 Methods for Electromagnetic Background Test
4.1 Preparations
4.2 Setting Basic Parameters
4.3 Measurement Procedure
4.4 Data Processing
Page 25HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Preparations Master local radio band planning and the usage of radio
equipment by enterprises
For pilot networks
− No available frequency is determined and the testing frequency is allocated
temporarily. During a spectrum test, you need to scan the entire band or
select several 5 MHz bands for test according to the local frequency
resources for use at the later phase.
For commercial networks
− Frequency resources are determined. The test focuses on the bands used
by the operator and is intended to eliminate interference at the bands in
use.
Page 26HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Preparations
Determine the test time and place
Uplink electromagnetic interference test
− Test place: the place where the NodeB antenna is installed.
− Conduct the test in three directions (0˚, 120˚ and 240˚).
− Use a portable antenna or the NodeB’s antenna.
Downlink electromagnetic interference test
− Select a certain quantity of typical points within the cell coverage for test.
− Conduct the test in three directions (0˚, 120˚ and 240˚).
− Use a portable antenna.
− Perform a drive test, drive the vehicle slowly along the main streets covered by a
cell and then stop the vehicle for further test when detecting the interference.
Page 27HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Preparations
Prepare tools and make sure
that they are available:
Spectrum analyzer
GPS receiver
Compass
Testing antenna
Vehicle
Page 28HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Preparations
Prepare tools and make them available:
Connect an LNA to the spectrum
analyzer with low receiver sensitivity.
During system connection, check
whether connectors are matched and
ensure continuous power supply for
the instruments.
Device Connector Model
Yagi antenna N (female)
Bandpass filter N (female)
YBT250 spectrum analyzer
N (female)
LNA SMA (male)
Feeder N (male)
Feeder N (male)/SMA (male)
50 ohm matched load
N (male)
YBT250 spectrum analyzer
Yaqi antenna
Filter
LNA
Cable
Page 29HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 4 Methods for Electromagnetic Background
Test
4.1 Preparations
4.2 Setting Basic Parameters
4.3 Measurement Procedure
4.4 Data Processing
Page 30HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Setting Basic Parameters
Set the following basic parameters
Parameter Parameter Value Remarks
FoUplink: Fo=1950; downlink: Fo=2140
(MHz)
Central frequency of the
spectrum under test
SPAN For example, SPAN=100 MHzSpan of the testable
spectrum
MaxHold
/Average
Select MaxHold or Average according to occurrent or continuous interference respectively.
Display the maximum value/the average value
RefLvl
Do not select AutoLevel. Set the reference level according to the testing signal and try to display the signal in the middle of the spectrum analyzer.
Reference level
Vertical Scale
10 dB/div (default) Vertical scale
Page 31HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 4 Methods for Electromagnetic Background
Test
4.1 Preparations
4.2 Setting Basic Parameters
4.3 Measurement Procedure
4.4 Data Processing
Page 32HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Measurement Procedure
Determining the test azimuth
Select the position where the NodeB antenna is installed for test. Usually, you
need to conduct the test in three directions. If the direction of the NodeB
antenna is determined, make the testing antenna be in the same direction as
the NodeB antenna.
Searching interference
Search interference within the uplink band and then within the downlink band.
Specific operations:
− Enter the YBT250 spectrum test interface and set Fo and Span.
− Fill in the record table, save data files, and check whether there is interference.
Judge rule: whether there is interference waveform higher than the noise floor.
Page 33HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Measurement Procedure Interference confirmation
During interference search, if there is interference, conduct a interference confirmation test. Specific steps are as follows:
− Enter the interface for measuring YBT250 NodeB test information, and set Fo to a central frequency point near interference, Span to 3 × interference bandwidth, and Channel Bandwidth to 4 M.
− Read the in-band interference power, fill in the record table, and save the data file.
In-band test
For the customer pilot, test the in-band power for all the candidate channels. For commercial offices, focus on testing the in-band power for the available channels. Specific steps are as follows:
− Enter the interface for measuring YBT250 NodeB test information, and set Fo to a central frequency point of the testing channel, Channel Bandwidth to 5 M, and Span to 3 × interference bandwidth.
− Read the in-band power, fill in the record table, and save the data file.
Page 34HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Measurement Procedure
Downlink drive test
Downlink drive test means driving a vehicle slowly along the main streets covered by a cell and conducting a point test after discovering large interference.
Specific operations:
− Enter the YBT250 spectrum test interface.
− Set Fo to 2140 MHz and Span to 60 MHz. Search interference when the vehicle moves at a speed lower than 15 km/h.
Point test items include:
− Set Fo to a central frequency point near the interference, Channel Bandwidth to 4 MHz, and Span to 3× interference bandwidth. Record the in-band interference power.
− Or set Fo to a central frequency point of the testing channel, Channel Bandwidth to 5 MHz, and Span to 3× channel bandwidth. Record the in-band power.
Page 35HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 4 Methods for Electromagnetic Background
Test
4.1 Preparations
4.2 Setting Basic Parameters
4.3 Measurement Procedure
4.4 Data Processing
Page 36HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Data Processing
After completing measurement, perform data
processing.
After completing measurement for the test area,
output
WCDMA Electromagnetic Interference Test Form
After completing measurement for the entire
local network, output
Report on WCDMA Electromagnetic Interference
Test
Page 37HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Question
Is the interference level obtained
from the electromagnetic
interference test equal to the
level of the interference signals at
the top of the NodeB or at the
antenna port of the MS?
Page 38HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Answer
The testing system and WCDMA
system adopt different antennas
and feeders. Therefore, you
need to calculate the level of the
interference signals at the top of
the NodeB or at the antenna port
of the MS according to the test
data during analysis.
Page 39HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Answer
Testing system
Antenna gain: 3 dBi
Feeder loss: 1 dB
Measured interference level: -90 dBm
WCDMA system
Gain of the NodeB antenna: 10 dBi
Feeder loss: 2 dB
Interference level at the NodeB: 90 - (3 -1) + (10 - 2) = -84 dBm
Page 40HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Question
How to estimate the power of the
interference level within the
channel bandwidth according to
the interference level within the
RBW?
Page 41HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Answer
The WCDMA system is a broadband system.
Therefore, you need to calculate the integral
power of the interference level within the
channel bandwidth.
RBW of the testing system: 10 KHz
Interference level within the RBW: -80 dBm
Channel bandwidth: 3.84 MHz
Integral power within the channel:
P = -80 + 10LOG(3.84*106/10*103) = -54dBm
Page 42HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 1 Impact of Electromagnetic Interference on the System
Chapter 2 Sources of Electromagnetic Background Interference
Chapter 3 Introduction to Interference Test Tools
Chapter 4 Methods for Electromagnetic Background Test
Chapter 5 Instructions for YBT250
Page 43HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Chapter 5 Chapter 5 Instructions for YBT250Instructions for YBT250
System connection
Power-on
Measurement
Measurement setting
Measurement result
Page 44HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
Before site survey, you need to conduct a spectrum test
and find proper frequency test instruments.
Tektronix YBT250 is recommended.
Features of YBT250
Portable, easy to carry
System integration, with a built-in LNA
Page 45HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
System connection
The matched antenna of YBT250 is Yagi
directional antenna.
A portable small antenna can be used for
electromagnetic background test.
YBT250 can use the battery delivered
together or can be externally connected to
the power supply.
Power-on
Press Power and enter the Windows CE
operating system.
Enter the measurement interface through
the touch screen of YBT250.
YBT250 spectrum analyzer
Yaqi antenna
Filter
LNA
Cable
Page 46HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
Measurement
YBT250 supports the following three
measurement functions:
− NodeB information measurement
− Spectrum test
− Interference source search
Spectrum test supports the following two
display modes:
− Spectrum mode
− Spectrogrum mode
Page 47HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
Measurement
The spectrum mode is used for real-time measurement.
− Determine the band to be tested and set Fo.
− Modify the span.
− Observe the spectrum diagram, adjust the Fo and span, and view whether there is
interference.
− The Trace menu includes the following options:
▪ Normal, Max Hold, Min Hold and Max/Min Hold
− Save the current spectrum diagram.
Note: You need to set RefLvl correctly to make the measured signal level
range from RefLvl to (RefLvl-70dB). The difference of the maximum level and
minimum of level that the YBT250 can correctly display is 70 dB.
Page 48HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
Measurement
The spectrogrum mode is used to check whether there is interference at a certain band in a specified time. The horizontal axis stands for the band and the vertical axis for the time.
Specific operations:
− Set the automatic storage option and a file name.
− Set the band (Fo and span).
− Open the saved file and view interference.
To view the exact interference, you can export the file as:
− A picture
− Data (.txt,.csv)
− Export the data from YBT250 using the U disk or network cable.
Page 49HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
Measurement setting
− Fo: the central frequency of the testing signal (unit: MHz)
− Span: It can be set to 100 MHz, 10 MHz or 5 MHz.
− RBW: It is automatically set by the instrument according to the span.
− MaxHold/Average: display the maximum value and the average value.
− RefLvl: set according to the interference level.
Measurement result
WCDMA Electromagnetic Interference Test Form and Report on WCDMA
Electromagnetic Interference Test
Page 50HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Instructions for YBT250
Page 51HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Conclusion
This course describes possible
interference sources at the WCDMA
band, methods for electromagnetic
background test, and instructions for
YBT250.
Thank You!www.huawei.com
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