03 WCDMA RNP CW Test and Propagation Model Tuning
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Transcript of 03 WCDMA RNP CW Test and Propagation Model Tuning
www.huawei.com
HUAWEI TECHNOLOGIES Co., Ltd. Page 1HUAWEI Confidential
WCDMA RNP CW Test and Propagation Model
Tuning
Internal
HUAWEI TECHNOLOGIES Co., Ltd. Page 2HUAWEI Confidential
Introduction
CW test (Continuous Wave test) is an importa
nt step of Propagation Model Tuning. Accor
ding to the CW test data (including latitude/l
ongitude and received level) and correspon
ding Digital maps, we can get the accurate
Propagation Model through tuning.
HUAWEI TECHNOLOGIES Co., Ltd. Page 3HUAWEI Confidential
Chapter 1 Principle of Radio Propagation
and CW Test
Chapter 2 CW Test Flow
Chapter 3 Analysis of CW Test Data
Chapter 4 Propagation Model Tuning
CONTENT
HUAWEI TECHNOLOGIES Co., Ltd. Page 4HUAWEI Confidential
Principle of Radio Propagation and CW Test
Section 1 Basic Principle of Radio Section 1 Basic Principle of Radio
PropagationPropagation
Section 2 Principle of Propagatio
n Model Tuning
Section 3 Purpose of CW Test
Section 4 Basic Principle of CW T
est
HUAWEI TECHNOLOGIES Co., Ltd. Page 5HUAWEI Confidential
Radio Waveband ClassificationRadio Waveband Classification
Frequencies in different bands have different propagation characteristics.
HUAWEI TECHNOLOGIES Co., Ltd. Page 6HUAWEI Confidential
Electric field Electric fieldElectric field
Oscillato
r
Transmission direction of electric wave
Magnetic fieldMagnetic field
Generation of Electromagnetic WaveBased on Maxwell equations set:
The variable magnetic field can excite eddy electric field and variable electric field can also excite eddy
magnetic field.
Continuous electromagnetic oscillation (electromagnetic wave) forms due to mutual excitation of
alternating electric and magnetic field.
The speed of electromagnetic wave only varies with electric and magnetic characteristics of medium.
The propagation speed of electric microwave in vacuum equals that of light in vacuum.
Light and electromagnetic wave are essentially the same. Light is electromagnetic wave of a certain
wavelength.
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Perpendicular incidence wave and ground reflection wave
(most common propagation modes)
Troposphere reflection wave (the propagation is very random)
Mountain diffraction wave (shadow area signal source)
Ionosphere refraction wave (beyond-the-horizon communication path)
Propagation Path
HUAWEI TECHNOLOGIES Co., Ltd. Page 8HUAWEI Confidential
Propagation of Electromagnetic Wave
Ripple in the pond: Energy is propagated around from the source point and gradually weakens.
Electromagnetic wave is similarly propagated except that (when the radiation source is isotropically eff
ective ideal point source):
It is propagated in the form of spherical wave in three-dimension space.
The propagation media are different, including air, obstacle and reflector.
HUAWEI TECHNOLOGIES Co., Ltd. Page 9HUAWEI Confidential
①Reflected wave of building②Diffracted wave③Direct wave④Reflected wave on the ground
Characteristics of Radio Propagation
Electric wave propagation system
of Land Mobile Communications
Radio propagation in
actual environment
LOS and NLOS
HUAWEI TECHNOLOGIES Co., Ltd. Page 10HUAWEI Confidential
Characteristics of Radio ChannelsCharacteristics of Radio Channels
d (m)
Pr (dBm)
10 20 30
-20
-40
-60
Slow fading
Fast fading Radio channels vary with user’s position and time.
Multipath scattering and obstruction result in acute changes to received power.
Slow fading• Attenuation: Pr is in direct
proportion to 1/dn.
• Shadow: obstructed by barriers
Fast fading• Multipath effect
Fast changes to signal strength at small distance and time interval
Doppler frequency shift Delay spread
HUAWEI TECHNOLOGIES Co., Ltd. Page 11HUAWEI Confidential
Diversity TechnologyDiversity Technology
Measures against fast fading- diversity technologies
- Explicit diversity• Space diversity• Polarization diversity• Frequency diversity : GSM-frequency hopping; WCDMA-spread
spectrum
- Implicit diversity• Implicit diversity uses signal processing technologies to hide diver
sity functions into signals under transmission, such as RAKE reception technology, interleaving and error code correction.
• Regarded as time diversity
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Delay SpreadDelay Spread Multipath propagation: Signals on different paths reach the receiver at
different time.
When the receiver fails to distinguish multipath signals, co-channel interference (CCI) occurs. In the WCDMA system, only the multipath delay larger than one chip period (0.26µs) can be recognized.
Typical value (µs): Open < 0.2, Suburban = 0.5, Urban = 3
Solutions Equalization and RAKE technologyEqualization and RAKE technology
HUAWEI TECHNOLOGIES Co., Ltd. Page 13HUAWEI Confidential
Doppler Frequency Shift Example of Doppler effect: A train is passing by you.
f1
f2
f3
V(km /h)
Doppler frequency shift in Mobile Communications
HUAWEI TECHNOLOGIES Co., Ltd. Page 14HUAWEI Confidential
T
R
T
R
• Diffraction loss • Penetration loss
• Clutter loss
Loss
HUAWEI TECHNOLOGIES Co., Ltd. Page 15HUAWEI Confidential
¦ È
¦ Ȧ Å0¦ Ì 0 ¦ Ŧ Ì ¦ Å0¦ Ì 0
d
Dw1 w2
E1
E2
XdBmWdBm
Penetration loss=X-W=B dBPenetration loss=X-W=B dB Reflection and refraction of electromagnetic wave through the wall
Indoor signals depend on penetration loss of building.
Signals are different at the indoor window and in the middle of room.
Building materials have great effect on penetration loss.
The reference angle of electromagnetic wave have great effect
on penetration loss.
Penetration Loss
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• Obstacle/penetration loss is: Partition obstruction: 5~ 20dB
Floor obstruction: > 20dB
Obstruction of furniture and other barriers: 2~ 15dB
Thick glass: 6~ 10dB
Penetration loss of the carriage of the train: 15~ 30dB
Penetration loss of lift: 30dB or so
Loss of thick leaves: 10dB
Penetration Loss
HUAWEI TECHNOLOGIES Co., Ltd. Page 17HUAWEI Confidential
Ground type WaterPaddy
fieldField
City,
mountain and
forest
Equivalent ground
reflection coefficient0.9~ 1 0.6~ 0.8 0.3~ 0.5 0.1~ 0.2
Reflection loss (dB) 0~ 1 2~ 4 6~ 10 14~ 20
Reflection Loss
HUAWEI TECHNOLOGIES Co., Ltd. Page 18HUAWEI Confidential
Radio Propagation EnvironmentRadio Propagation Environment
Radio propagation environment determines the propagation models directly. And propagation environment is impacted by the following factors:• Landform: mountain, hill, plain, waters, and vegetation • Clutter: building, road and bridge• Noise: natural noise and artificial noise• Climate: rain, snow and ice (tiny effect on UHF band)
HUAWEI TECHNOLOGIES Co., Ltd. Page 19HUAWEI Confidential
Radio Propagation EnvironmentRadio Propagation EnvironmentType of radio environment
Radio environment is classified as follows, according to ITU-R P.1411-1
and specific conditions in China.
Propagation
environmentDescription
Dense urbanMany tall buildings, signals fail to diffract from the roof of
building .
UrbanSignals can diffract from the roof due to low buildings and wide
streets.
Suburban Low and sparse buildings
Rural Low and sparse buildings, but with lots of vegetation
Mountainous areas
Road
Indoor
HUAWEI TECHNOLOGIES Co., Ltd. Page 20HUAWEI Confidential
Radio Propagation EnvironmentRadio Propagation Environment
Type of propagation environment
The corresponding cell type is as follows:
Cell type Cell type Typical antenna installation
Macro-cell >500 mInstalled outdoors, higher than average height of
surrounding roofs
Micro-cell 100~500mInstalled outdoors, lower than average height of
surrounding roofs
Pico-cell <100mInstalled outdoors or indoors, lower than height of all
roofs
Type of other new cells, such as Mini-cell…
HUAWEI TECHNOLOGIES Co., Ltd. Page 21HUAWEI Confidential
Principle of Radio Propagation and CW Test
Section 1 Basic Principle of
Radio Propagation
Section 2 Theory of Propagation Section 2 Theory of Propagation
Model TuningModel Tuning
Section 3 Purpose of CW Test
Section 4 Basic Principle of CW
Test
HUAWEI TECHNOLOGIES Co., Ltd. Page 22HUAWEI Confidential
Radio Propagation Model
Propagation model is used to predict the effect of terrain, obstacle and artificial environment on the path loss.
WCDMA common propagation modelsWCDMA common propagation models
HUAWEI TECHNOLOGIES Co., Ltd. Page 23HUAWEI Confidential
Okumura/Hata model
For: 900M- 2000MHz
COST231-Hata model
For: 1500-2000MHz
COST231 Walfish-Ikegami model
For: 800M-2000MHz
Keenan-Motley model
For indoor propagation
Propagation model in UNET
For macro cell on 300M- 2000M
Common propagation models
Radio Propagation Model
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Radio Propagation Model
L=K1 + K2log(d) + K3log(HTxeff) + K4×Diffraction + K5log(d)×log(HTxeff) + K6(HRxeff) + Kclutterf(clutter)
K1: constant (dB)K2: multiplier factor of log(d)d: distance between Tx antenna and Rx antenna (m)K3: multiplier factor of log(HTxeff)HTxeff: effective height of Tx antenna (m)K4: multiplier factor of diffraction loss, which must be a positive valueDiffraction loss: diffraction loss through the path with barriers (dB)K5: multiplier factor of log(HTxeff)log(d)K6: multiplier factor of HRxeffHRxeff : effective height of Rx antenna (m)Kclutter: multiplier factor of for f(clutter)f(clutter): average weighted loss caused by clutter
Model in UNET:
HUAWEI TECHNOLOGIES Co., Ltd. Page 25HUAWEI Confidential
Principle of Radio Propagation and CW Test
Section 1 Basic Principle of Rad
io Propagation
Section 2 Theory of Propagatio
n Model Tuning
Section 3 Purpose of CW TestSection 3 Purpose of CW Test
Section 4 Basic Principle of CW
Test
HUAWEI TECHNOLOGIES Co., Ltd. Page 26HUAWEI Confidential
Purpose of CW Test
Compare CW test data w
ith prediction results, and
then tune the propagatio
n parameters to improve
the accuracy of coverage
prediction.
GPS
HUAWEI TECHNOLOGIES Co., Ltd. Page 27HUAWEI Confidential
Principle of Radio Propagation and CW Test
Section 1 Basic Principle of Rad
io Propagation
Section 2 Theory of Propagatio
n Model Tuning
Section 3 Purpose of CW Test
Section 4 Basic Principle of CW Section 4 Basic Principle of CW
TestTest
HUAWEI TECHNOLOGIES Co., Ltd. Page 28HUAWEI Confidential
Basic Principle of CW Test
Typification
The CW test data must represent the characteristic of elec
tromagnetic wave in this area.
Balance
The CW test data must represent the characteristic of elec
tromagnetic wave by the proportion of different clutters in t
his area.
HUAWEI TECHNOLOGIES Co., Ltd. Page 29HUAWEI Confidential
Chapter 1 Principle of Radio Propagation
and CW Test
Chapter 2 CW Test Flow
Chapter 3 Analysis of CW Test Data
Chapter 4 Propagation Model Tuning
CONTENT
HUAWEI TECHNOLOGIES Co., Ltd. Page 30HUAWEI Confidential
CW Test Flow
Section 1 Site SelectionSection 1 Site Selection
Section 2 Building Test
Platform in Networking
Section 3 Drive Test
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Site Selection
Principles of site selection
Number of sites: It is usually agreed that a minimum of 5 sites should be
tested in large and dense city, but one site is enough in the city, which
mainly depends on antenna height and EIRP.
Representation: Site selection should aim to cover all types of clutter
(from the digital map) in the coverage zone.
Multiple models: Define the corresponding zone of each model if the test
environment requires multiple models to describe its propagation
characteristics.
Overlap: Increase measurement overlap area between each site as
much as possible. But reasonable inter-site distance should be ensured.
Obstacle: The data should be filtered in the subsequent processing if
obvious obstacle exists.
HUAWEI TECHNOLOGIES Co., Ltd. Page 32HUAWEI Confidential
Site SelectionStandards of site selection
a. Antenna height should be greater than 20m.
b. The antenna should be 5m higher than the nearest
obstacle.
c. The obstacle mainly refers to the highest building on the roof where the antenna is installed. The building where the site is located should be higher than average height of surrounding buildings.
5m
HUAWEI TECHNOLOGIES Co., Ltd. Page 33HUAWEI Confidential
CW Test Flow
Section 1 Site Selection
Section 2 Building Test Section 2 Building Test
Platform in NetworkingPlatform in Networking
Section 3 Drive Test
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Building Test Platform in Networking
Tx subsystem: Tx antenna, feeder, high-frequency signal source and
antenna holder
Rx subsystem: test receiver, GPS receiver, test software and laptop
High frequency signal
source
Signal source TMA
Power supply
Tx antenna
Rx antenna Drive test instrument
Build-in GPS
Laptop
RF cable 1 RF cable 2
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Building Test Platform in Networking
Record the gain of the following parts on signals durin
g networking:
Tx power of signal source
Loss of RF cable
Gain of Tx antenna
Gain of Rx antenna
HUAWEI TECHNOLOGIES Co., Ltd. Page 36HUAWEI Confidential
CW Test Flow
Section 1 Site Selection
Section 2 Building Test
Platform in Networking
Section 3 Drive TestSection 3 Drive Test
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Drive Test
Keep to the following standards to select a test path
Landform: The test route must cover all main landforms in the area.
Height: The test route must cover landforms with different height in this area if t
he landforms are up-and-down.
Distance: The test route must cover different positions from the site in the area.
Direction: The test points must be consistent on the horizontal and vertical rout
e.
Length: The total distance of one CW test should be longer than 60km.
Number of test points: The more, the better.
Overlap: Overlap the test route in different sites as much as possible to improv
e the reliability of models.
Obstacle: Shadow areas behind this wall should be avoided when antenna sig
nals are obstructed by the wall at a side.
HUAWEI TECHNOLOGIES Co., Ltd. Page 38HUAWEI Confidential
Drive Test
Lee criteria for sampling: 50 samples by 40λ
The maximum vehicle speed: Vmax=0.8λ/Tsample
Delete test results from the sampled data under abnormal conditi
ons:
Fading over 15~30db without reasonable causes
In tunnels
Under the viaducts
Select test routes from the main lobe coverage area if directional
antennas are adopted for a CW test.
HUAWEI TECHNOLOGIES Co., Ltd. Page 39HUAWEI Confidential
Chapter 1 Principle of Radio Propagation
and CW Test
Chapter 2 CW Test Flow
Chapter 3 Analysis of CW Test Data
Chapter 4 Propagation Model Tuning
CONTENT
HUAWEI TECHNOLOGIES Co., Ltd. Page 40HUAWEI Confidential
Analysis of Test Data
Section 1 Data FilteringSection 1 Data Filtering
Section 2 Data Dispersion
Section 3 Data Binning
Section 4 Format Conversion
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Data Filtering
Data to be filtered is as follows:
1. Data tested in the places where
GPS is unable to locate accurately
(such as under the overhead rack,
in the tunnel).
2. Data obtained when the distance
to antenna is too near or far.
3. Data obtained with too weak
signals.
4. Error data caused by inexact AP
(antenna pattern).
5. Other data inconsistent with the
requirements during the route
design of CW test.
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Analysis of Test Data
Section 1 Data Filtering
Section 2 Data DispersionSection 2 Data Dispersion
Section 3 Data Binning
Section 4 Format Conversion
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Data Dispersion
Propagation in mobile communications can be indicated as
follows:
r(x) = m(x)r0(x)
X: distance
r(x): received signals
r0(x): Raileigh Fading
m(x): local mean value, the combination of long-term fading
and space propagation loss
2L: average length between sampling areas, also called
intrinsic length
Lx
Lx
dyyrL
xm )(2
1)(
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Data Dispersion
The CW test is to obtain the local mean value of each geography
location in some areas as far as possible, i.e. the difference of r(x) and
m(x) should be the minimum value. In this sense, effect of Raileigh
Fading should be excluded.
When the intrinsic length equals 40 wavelength and the number of
sampling points is 50, the difference of test data and actual local mean
value can be less than 1dB according to Lee criteria.
Intrinsic length is average length for binning (2G band is 6 m long,
namely, 40 wavelength)
Since the locating speed of GPS is far lower than the receiving
speed of the receiver, the dispersion processing is required before the
binning.
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Data Dispersion
The principle of dispersion processing is as follows:
Conditions:
− There are many test records arranged under each locating
point in time sequence because the receiving speed of the
receiver is far higher than the locating speed of GPS.
− The vehicle speed between two locating points is uniform.
− The time interval between every two measurement records is
the same.
Processing:
− Equally distribute these records to the route section between
two points in time sequence so that there will be sufficient
points in every 6m range on test route.
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Analysis of Test Data
Section 1 Data filtering
Section 2 Data Dispersion
Section 3 Data BinningSection 3 Data Binning
Section 4 Format Conversion
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Data BinningObjectives:
Reserve the impact of slow fading but eliminate the fast
fading
Methods:
Method 1: make grids for the whole area with 6m side,
perform the arithmetic average for the data located in each
grid, and then take the grid center as the new location.
Method 2: divide the path into sections in equal interval
with 6m for each, and perform the arithmetic binning for the
data in each section to select some point for the location of
mean value.
Tool: CW Data Editor
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Analysis of Test Data
Section 1 Data Filtering
Section 2 Data Dispersion
Section 3 Data Binning
Section 4 Format ConversionSection 4 Format Conversion
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Format Conversion
The data format exported by Agilent E74xx Series is
Data format imported to UNET is
Format conversion can be implemented manually (saved a
s .dat file)
X Y CW_Power_List_
_Freq__Hz
CW_Power_List__A
mpl__dBm
Time Date
X Y CW_Power_List__Ampl__dBm
HUAWEI TECHNOLOGIES Co., Ltd. Page 50HUAWEI Confidential
Chapter 1 Principle of Radio Propagation
and CW Test
Chapter 2 CW Test Flow
Chapter 3 Analysis of CW Test Data
Chapter 4 Propagation Model Tuning
CONTENT
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Propagation Model Tuning
Section 1 PreparationSection 1 Preparation
Section 2 Propagation Model
Tuning
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Preparations
Installing network planning software:
UNET is powerful planning and optimization
software and model tuning is only one of its
functional modules.
Creating a project
In UNET, perform planning and optimization
model tuning based on each project.
Importing antenna pattern file
Correctly import the antenna pattern varying with
different manufacturers
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Propagation Model Tuning
Section 1 Preparations
Section 2 Propagation ModSection 2 Propagation Mod
el Tuningel Tuning
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Propagation Model Tuning Flow
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Propagation Model Tuning
Establishing a model
Establish a standard macrocell model to be tu
ned.
Select the effective antenna height.
Select a calculation method of diffraction loss.
Importing data
Import CW test data file into the project.
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Propagation Model TuningMap correction
GPS locating in CW test usually adopts WGS84 and UTM
projection. However, digital maps in China do not use such
projections and reference plane. Correct digital maps if CW
test data does not correspond to them.
Correction method:
− Correct four parameters on rectangular coordinates
in a digital map to realize the optimal match with the
test data.
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Propagation Model Tuning
Setting Filtering
Distance filtering:
− Filter the data of which r is less than
150m or r is greater than 3000m.
Signal strength filtering:
− Filter the data of which Signal is greater
than -40dBm or Signal is less than -
121dB.
Clutter filtering
− Filter the Clutter in which sampling
points are less than 300.
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Propagation Model Tuning
Parameter tuning
L=K1 + K2log(d) + K3log(Heff) + 4×Diffraction
+ K5log(d)×log(HTxeff) + K6(HRxeff)
+ Kclutterf(clutter)
Tune such parameters as log(d), log(Heff),
Diff, log(d)log(Heff), Hmeff and Klutter to
finally tune SPM propagation model.
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Propagation Model Tuning
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Propagation Model Tuning
calculated values for the variable
ERROR (measurement – prediction)
Regression line
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Propagation Model Tuning
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Propagation Model Tuning
Correction of propagation model parameters in a city
Parameter K Reference value
K1 23.2
K2 44.90
K3 5.83
K4 0.5
K5 -6.55
K6 0
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Propagation Model TuningAnalysis of correction results
Analyze correctness of the acquired model after correction.
Evaluate the correctness of the model with Std Dev, which
refer to the binding degree of the acquired model and actual
test environment.
Make Std Dev less than 8 as much as possible in actual mo
del tuning, which indicates that the tuned model and actual t
est environment are well bound.
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Summary
After completing this course, you should be able
to master:
Principle and purpose of CW test
Process of CW test
Process of propagation model tuning
Thank youwww.huawei.com