7-1 WCDMA Radio Network Coverage Planning .ppt

5/19/2018 7-1 WCDMA Radio Network Coverage Planning .ppt

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HUAWEI TECHNOLOGIES CO., LTD. All rights reserved

www.huawei.com

Internal

WCDMA Radio Network

Coverage Planning


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HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 2

Upon completion of this course, you will be able to:

Know the contents and process of network planning.

Understand the uplink budget and its elements.

Understand the downlink budget and its elements.

Familiarize the coverage enhancement technologies. .


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Chapter 1 Process of WCDMA Network Planning

Chapter 2 Uplink Budget

Chapter 3 Downlink Budget

Chapter 4 Coverage Enhancement Technologies


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1.1 Overview of Radio Network Planning

1.2 Huawei Concept of Radio Network Planning

1.3 Process of Radio Network Planning


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Definition and Category of Network Planning

Focus of the train:

Planning of radio network.

Definition:

Network planning means that proper network elements (NEs) are

selected according to the network target, network evolution

requirement, and cost, and then the quality, configuration, and

connection mode of the NEs are determined to facilitate engineering

implementation.

Categories:

Planning of core network

Planning of radio network

Planning of transmission network


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Importance of Radio Network Planning in 3G

Importance:

The construction cost of the mobile

communications network mainly lies in the

equipment investment.

Among the three parts of the 3G network

(radio access network, transmission network,

and core network), the radio access network

occupies more than 70% investment.

The investment in the radio access network

depends on the number and configuration of

the BSs.


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Compare WCDMA Network Planning with that of GSM

In the GSM system, the structure and

frequency of the cellular network are planned

in order to ensure that the co-frequency and

adjacent-frequency interference meet the call

quality requirement.

If the interference requirement is met, the

number of supported subscribers can be

calculated based on the number of carrier

frequencies and the number of timeslots.

The coverage of the GSM system depends on

the transmit power of the transmitter and the

demodulation performance of the receiver.

The GSM mainly offers voice service, and the

GoS and design objective are relatively simple.

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WCDMA uses the spread spectrum technology,

so it can realize 11 frequency multiplexing

without frequency planning.

The capacity of each carrier in WCDMA is

"soft" because it is related to factors such as

environment and adjacent-cell interference.

The coverage of the WCDMA system is related

to the system load. If the system load

increases, the coverage will shrink.

The WCDMA system supports services with

different rate and QoS, including voice service,

and their coverage capacity is different. In the

network planning, the system performance

shall be optimized through reasonableplanning and radio resource management.

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Huawei Concept of Wireless Network Planning

Optimal coverage for profitable services

The 3G network is a multi-service network, so the network resources need be

distributed among different services. The cell radius and coverage scheme

should be determined after the profitable services and their coverage quality

are determined. At the early stage of the 3G network, if the planning focuses

on high-speed data service, it will result in waste of the BSs because there arenot enough services.

Competitive core service

Core service refers to the service that have a long-term effect on the network

development. It is possible that the core service is not profitable in a short

period, but is the attraction of the subscriber increase and service

development, for example, high-speed data service. Therefore, the quality of

the core service should be guaranteed in order to show the service and

performance advantages of the 3G network and promote the operator's brand.




Highest capacity based on limited resources

The capacity of the 3G network is mainly affected

by interference. Reasonable parameter planning

may help to reduce intra-cell and inter-cell

interference, improve the cell capacity, and make

full use of the limited resources.




Lowest overall cost of network construction

The construction of the radio network goes through

the lifecycle of the network. In the planning, further

development shall be considered, in order to

reduce the total cost of network construction.


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Process of Wireless Network Planning

Radio Network Dimensioning (RND)

At the early stage of the project planning, the future

network is preliminarily planned, and the configuration and

the number of RAN NEs are output for preliminary project

negotiation and for cost estimation in contract signing.

Pre-planning of radio network

At the mid stage of project planning, based on the

dimensioning output, the future network is planned in

detail, and the accurate network scale and theoretical site

location are determined. A pre-planning report will beoutput for mid-stage project and cost estimation in

contract signing.


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Process of Wireless Network Planning

Cell planning of radio network

At the later stage of project planning, based on the

pre-planning output, each selected site is surveyed,

and the related cell parameters are determined. If theresult is quite different from the planning, the cell

parameters and planning effect should be checked

through simulation, and the output report would be

the final radio network planning scheme that can

guide the project implementation.


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Process of Radio Network Planning


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Network dimensioning is an iterative process

Downlink analysis checks whether NodeB power is enough to cover the users

Radio Network Dimensioning


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Radio Network Dimensioning

Radio network dimensioning is a simplified analysis of

the future network.

Objective:

To obtain the network scale (Approximate BS

quantity and configuration), to obtain theconstruction period, and to obtain information such

as electronical cost and human resource cost.

Method:

Select a proper propagation model, and subscriber

mobility, distribution, and traffic models, and thenestimate the site quantity, cell quantity, coverage

size and capacity.


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Requirement of RND parameters

Information of coverage area

The engineers of RNP should know exact informationabout coverage area ,for example :

Area , economy, population

Distribution of cluster

The information of mobile communication market

Target of network

The target of network should include several factors:

Service Coverage area & Coverage quality

Network Capacity

Target load of cell


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Requirement of RND parameters

Limited by network scale & Building plan in different phase

Base on commercial contract

Base on RND result if there is no commercial contract

Information of available site

For a new operator who doesnt have abundant 2G mobile

communication network sites, the RNP engineer shouldcollect exact information about available site.


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Radio Network dimensioning

Coverage information

Coverage area

Coverage probability

Capacity informationTraffic model

Service model

Subscriber density

Quality information

QoS requirement

GoS requirement

Demodulation threshold

System scale

Site quantity

System configuration

Sector structure

Carrier quantity

Network construction cost

Site cost

Equipment cost

Input Output

Coverage dimensioning

Capacity dimensioning


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Radio Network Pre-planning

Based on radio network

dimensioning, the network pre-

planning intends to determine

the initial layout and theoretical

location of the BSs and select

engineering parameters (BS

location, network hierarchy,

transmit power, antenna

layout/type/direction/tilt angle,

and so on) and some cell

parameters (common channel,

transmit power of traffic

channel, orthogonal factor, cell

scrambling code, and so on) .


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Based on the result of RND,theoretical location of site,

parameters of project, parameters of

cell, We should carry out coverage

simulation.

We should carry out more detailedadjustment (for example amount of

NodeB, configuration of NodeB,

antenna altitude, antenna azimuth)

after analyzing the results of

coverage simulation.

Finally ,we should get perfect

coverage result.


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Radio Network Pre-planning report

We should output Radio Network Pre-planning report after finishing

previous jobs. Radio Network Pre-planning report should include

following factors:

Introduce of project background

Information of planning area :area, population, cluster

Project of radio network pre-planning: site distribution map, site list

( include site name, latitude ,longitude, parameters) Performance of project :based on the simulation result

Appendix: statistical diagram about performance


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Radio Network Cell PlanningF lowchart of cell planning

N

Site survey

report

Site selection

System

emulation

Design

objectivemet?

Wireless network

planning report

Noise test

Noise test report

Wireless network

pre-planning

report

Site survey

N

NewSite2G

SearchRings

Yes

Site list

New site (prefix:NewSite)?

2G site?

Output Search

Rings

Obtaincandidate sites

Site conditionsdetermined?

Site survey report

Site

requirement

met?

Yes

Site survey

No

Noise test Noise test report

Wireless network

pre-planning

reportYes

No

No

Yes

Yes

No


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Radio Network Cell Planningsite survey In fact , perfect site position could not be acquired. We must select some backup

site. But how can we select the backup site?

Based on experience , backup site is selected in SEARCH RING scope ,SEARCH RING =1/4*R, at the same time ,we still consider its height.

We still pay attention to some other factors when we select the backup sites :

Radio propagation

Site position Site height

Surrounding

Job implementation

Space of room

Antenna installation Transmission

Power

Commercial factor

Rent


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Radio Network Cell PlanningSystem Simulation

System Simulation class

Static simulation

Static simulation focus on user

behavior such as browsing Internet,

call.

Dynamic simulation

Dynamic simulation focus on detail

of user behavior such as duration

and data rate of browsing.

At present, Static simulation is in common

use. Monto Carlo simulation is one type of

static simulations

The example of Monto Carlo

simulation


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Distribution of NodeBs


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Simulation diagrampilot coverage intensity


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Simulation diagrampilot coverage quality (Ec/Io)


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Coverage probability of 12.2k voice service


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Coverage probability of 64k video phone service


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Coverage probability of 144k Net Meeting service


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Coverage probability of 384k HTTP service


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Simulation result about pilot pollution


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Process of Coverage Budget

Environment features of the

planned area

Site capacity

Indoor coverage

Coverage probability

Propagation model

Equipment performance

Create link budget

Obtain cell radius

Calculate site area

Specify site quantity

of the area

Maximum path loss

Minimum cell radius

Maximum site

coverage area

Site quantity=planned area/site coverage area


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Fundamental Principle

Link Budget: LinkBudget intends to

estimate the

system coverage

by analyzing the

factors of the

propagation of theforward signal

and reverse

signal, in order to

obtain the

maximum

propagation lossafter certain

communications

quality is ensured.

TX

Combiner

DuplexerFeeder

RX

Pout_BS

Lc_BSLf_BS

Ga_BSNodeB

TX

RX

Pout_UE

Ga_UE

UE

CombinerDuplexer

Body Loss

Fading

Margin

Penetration

Loss


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Algorithm Introduction

PL_UL=Pout_UE +Ga_BS+Ga_UELf_BS+Ga_SHOMpcMf

MILpLbS_BS

PL_UL: Maximum propagation loss of the Uplink

Pout_UE: Maximum transmit power of the traffic channel of the UE

Lf_BS: Cable loss Ga_BS: Antenna gain of the BS; Ga_UE: Antenna gain of the MS

Ga_SHO: Gain of soft handover

Mpc: Margin for fast power control

Mf: Slow fading margin (related to the propagation environment)

MI: Interference margin (related to the designed system capacity)

Lp: Penetration loss of a building (used if indoor coverage is required)

Lb: Body loss

S_BS: Sensitivity of BS receiver (related to factors such as service andmulti-path condition)

Uplink (reverse)


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Elements of WCDMA Uplink Budget

Max Power of TCH

Body Loss

Gain of UE Tx Antenna

EIRP

Gain of BS Rx AntennaCable Loss

Noise Figure (BS)

Required Eb/No (BS)

Sensitivity of BS Receiver

UL Cell Load

Interference Margin

Background Noise Level

SHO Gain over Fast Fading

Fast Fading Margin

Minimum Signal StrengthRequired

Penetration Loss

Std. dev. of Slow Fading

Edge coverage Probability

Slow Fading Margin

SHO Gain over Slow Fading


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1.Max Power of TCH (dBm)

For a UE, the maximum power of each traffic channel is usually the

nominal total transmit power. There are many types of UE in a

commercial network, so this parameters should be reasonably set in

the link budget according to the specifications of a mainstream

commercial cell phone and the requirement of the operator.

Grade of UE powerTS 25.101 v3.7.02001-066.2.1

Power Class Nominal maximum output power Tolerance

1 +33dBm +1/-3dB

2 +27dBm +1/-3dB

3 +24dBm +1/-3dB

4 +21dBm +2/-2dB


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2. Body Loss (dB)

For voice service, the body loss is 3 dB.

Because the data service mainly involves reading and video,

so the UE is relatively far from body, and the body loss is 0

dB.

3. Gain of UE Tx Antenna (dBi)

In general, assume that the receiver gain and transmitter

gain of the UE antenna are both 0 dBi.

4. EIRP(dBm)UE EIRP (dBm)

= UE Tx Power (dBm) - Body Loss (dB)

+ Gain of UE Tx Antenna (dBi)


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Elements of WCDMA Uplink Budget 5. Gain of BS Rx Antenna (dBi)

Kathrein 741794

Frequency range

1710~2170MHz (dual

band for DCS and

UMTS)

Polarization +45, -45

Gain 18.5dBi

HPBW (1920~2170MHz)Horizontal: 63

Vertical:6.5

Electrical tilt Fixed, 2

Side lobe suppression for 1stside

lobe above horizon>14dB

Front-to-back ratio, co-polar >30dB

dimensioning (Height / Width /

Depth)

1302 mm / 155 mm / 69

mm

Weight 6.6kg

Kathrein 741790

Frequency range 1920~2170MHz

Polarization Vertical

Gain 11dBi

HPBW Vertical: 7

Electrical tilt Fixed, 0

dimensioning (Height) 1387 mm

Weight 5kg


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6. Cable Loss (dB)

It includes the loss of the feeders andconnectors between the cabinet top andthe antenna connector.

Lower jumper

Connector

Feeder

Upper jumper

Etc.

Except for the feeder, the loss isrelatively constant. Assume that theconnecter loss is 0.8 dB.

7/8-inch feeder: 6.1 dB / 100m for 2GHz

5/4-inch feeder: 4.5 dB / 100mfor 2GHz

Bracket

Bracket

Tilt adjuster

Antenna

Upper jumper

Feeder

Feeder windowLightning arrester

Lower jumper

Feeder fixing clip

Feeder grounding clip

Feeder installation


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Elements of WCDMA Uplink Budget 7. Noise Figure (dB)

Noise figure (NF): It is used to measure the noise

performance of an amplifier. It refers to the ratio of the input

SNR to the output SNR of the antenna.

Thermal noise of receiver (unit bandwidth):

PN = KTBWNF

= -174 (dBm/Hz) + 10lg(3.84MHz / 1Hz) + NF(dB)

= -108 (dBm/3.84MHz) + NF (dB)

NF = SNRi/ SNRo

= (Si/ Ni) / (So/ No)


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Elements of WCDMA Uplink Budget 8. Eb/No Required (dB)

It is obtained through link simulation. It is related to the following:

Configuration of receiver diversity

Multi-path channel condition

Bearer type

9. Sensitivity of BS Receiver (dBm)

Sensitivity of Receiver (dBm)

= -174 (dBm/Hz) + NF (dB) + 10lg(3.84MHz/1Hz)

+ required Eb/No (dB) - 10lg[3.84MHz/Rb(kHz)]

= -174 (dBm/Hz) + NF (dB) + 10lg[1000 * Rb (kHz)] + Eb/No (dB)


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10. Background Noise Level (dBm)

External electromagnetic interference sources:

Wireless transmitters (GSM, microwave, radar,

television station, and so)

Automobile ignition

Lightning

For the planning for a specific area, it isrecommended to estimate the local interference

through noise test.


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Elements of WCDMA Uplink Budget 11. Penetration Loss (dB)

Indoor penetration loss refers to the difference between the

average signal strength outside the building and the average signal

strength of one layer of the building.

The penetration loss is related to building type, arrive angle of the

radio wave, and so on. In the link budget, assume that the

penetration loss is subject to the lognormal distribution. The

penetration loss is indicated by average penetration loss and

standard deviation.

It is uneconomical to provide better indoor coverage through an

outdoor BS. The indoor coverage shall be provided through a

reasonable indoor coverage solution.

In the actual construction of a commercial network, the penetration

loss margin is usually specified by the operator in order to compare

the planning results of different manufacturers.


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12. Fast Fading Margin (dB)

In the link budget, the demodulation performance of the used receiver is

the simulation result based on the assumed ideal power control. In an

actual system, because of the limited transmit power of the transmitter,

non-ideal factors are introduced in the closed loop power control.

Effect of power control margin on the uplink demodulation performance:

The simulation shows the following: When the HeadRoom is large,

the target Eb/No set in the outer loop power control is appropriate to

the simulation result under the ideal power control. As the power

margin decreases, the Eb/No gradually increases (if the powermargin decreases by 1 dB, the required Eb/No increases by about 1

dB). If power control performance is almost not available, the

BER/BLER cannot be ensured.


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13. Edge coverage ProbabilityWhen the transmit power of a UE hits the threshold, but the path loss does

not meet the requirements for the lowest receive level, the link will be

disconnected.


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SF x dnorm x 0

30 20 10 0 10 20 300

0.02

0.04

0.06

SF x 8( )

SF x 10( )

SF x 12( )

x

SF_M x pnorm x 0

20 16 12 8 4 0 4 8 12 16 200

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

SF_M x 8( )

SF_M x 10( )

SF_M x 12( )

x


14. Slow Fading Margin (dB)

Key point: Property of normal distribution.

Slow Fading Margin (dB) = required edge coverage ProbabilityStd.

dev. of Slow Fading (dB)


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15. Uplink Cell Load

Uplink cell load is used to measure the uplink load of a cell.

The higher the uplink cell load, the higher the uplink interference.

If the uplink load is about 100% , the uplink interference becomes infinite,

and the corresponding capacity is the limit capacity.

N

jjjN

jULW

vREbvsNoiLi

11

11


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16. Uplink Interference Margin (dB)

50% Load3dB

60% Load4dB

75% Load6dB


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17. SHO Gain Fading (dB)

The soft handover gain includes two parts:

Multiple related soft handover branches lower the

required margin for fading, which results in multi-cell

gain.

Gain for the link demodulation of the soft handover :

marco diversity combining gain.

The SHO Gain over Fast Fading refer to the macro

diversity combination gain.

Slow fading between BSs is partly irrelevant, and an

MS can select a better BS through soft handover


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19. Minimum Signal Strength Required (dBm)

After the interference factors and the factors

degrading the performance are considered, the signal

strength required by the correct demodulation is

receiver sensitivity in the network.

Minimum Signal Strength Required

= Sensitivity of Receiver (dBm) - Gain of Antenna (dBi)

+ Body Loss (dB) + Interference Margin (dB)

+ Margin for Background Noise (dB) - SHO Gain over

fast fading (dB) + Fast Fading Margin (dB)


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Summary: Cell edge path loss

Based on the maximum path loss allowed by the link,

the path loss at the cell edge can be calculated if the

fading margin and soft handover gain for providing the

required edge/area coverage probability and the

penetration loss of indoor coverage are considered.

Path Loss (dB) = [ EiRP (dBm) - Minimum Signal

Strength Required (dBm) ]- Penetration Loss (dB) -

Slow Fading Margin (dB) + SHO Gain over Slow

Fading (dB)


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Fundamental Principle

Link Budget: Link

Budget intends to

estimate the system

coverage by

analyzing the factors

of the propagation

of the forward signal

and reverse signal, in

order to obtain the

maximum

propagation loss after

certain

communications

quality is ensured.

TX

Combiner

DuplexerFeeder

RX

Pout_BS

Lc_BSLf_BS

Ga_BSNodeB

TX

RX

Pout_UE

Ga_UE

UE

CombinerDuplexer

Body Loss

Fading

Margin

Penetration

Loss


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Algorithm

PL_DL=Pout_BSLf_BS+Ga_BS+Ga_UE +Ga_SHOMpcMfMILpLbS_UE

PL_DL: Maximum propagation loss of the downlink

Pout_UE: Maximum transmit power of the traffic channel of the BS

Lf_BS: Cable loss

Ga_BS: Antenna gain of the BS; Ga_UE: Antenna gain of the MS

Ga_SHO: Gain of soft handover

Mpc: Margin for fast power control

Mf: Slow fading margin (related to the propagation environment)

MI: Interference margin (related to the designed system capacity)

Lp: Penetration loss of a building (used if indoor coverage is required)

Lb: Body loss

S_UE: Sensitivity of UE receiver (related to factors such as service and

multi-path condition)

Downlink (forward)


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Elements of WCDMA Downlink Budget

Max Power of TCH

Cable Loss

Gain of BS Tx Antenna

EIRP

Gain of UE Rx Antenna

Body Loss

Noise Figure (UE)

Required Eb/No (UE)

Sensitivity of UE Receiver

DL Cell Loading

Interference Margin

Background Noise Level

SHO Gain over Fast Fading

Fast Fading Margin

Minimum Signal Strength

Required

Penetration Loss

Std. dev. of Slow Fading

Edge coverage Probability

Slow Fading Margin

SHO Gain over Slow Fading


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Elements of WCDMA Downlink Budget 1.Downlink Cell Load

Downlink cell load factor is defined in two ways:

Downlink cell load at the receiver:

Downlink cell load at the receiver: The ratio of the current cell transmitpower to the maximum BS transmit power. Characteristics:

The higher the downlink cell load, the higher the cell transmit power.

The downlink cell load is related to service type, UE receiver

performance, cell size, and BS capability.

N

j

j

jjjDL vW

REbvsNoi

1

1


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: 1.78

Elements of WCDMA Downlink Budget

2.Downlink Interference Margin (dB)

Downlink interference at UE receiver:

The downlink load factor is:

The link budget tool uses the following typical values:

orthogonal factor : It is obtained through simulation. It is related toenvironment type and cell radius.

Cell edge adjacent-cell interference factor

N

N

N

nnj

T

j

T

j

N

total

P

PPL

PPL

P

P

IjNoiseRise

1

,

1)1(

)(

jDLf ,

N

n nj

ownj

PL

PL

1 ,

,

j

J

jjDLj

jjjob

DL f

W

RVNE

1,

)1(/

,where =


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Tower Mounted Amplifier (TMA)

TMA

A TMA locate the position

under the antenna

A TMA is Low noise amplifier

A TMA helps to improve the

uplink receive sensitivity and

enhances the uplink coverage

A TMA usually has 0.7dB loss

in the downlink.


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4-antennas Reception Diversity

4Antenna reception diversity

4Antenna reception diversity hastwo types

Two Cross-polarizationantennas

Four antennas

4Antenna reception diversityhelps to improve the uplinkreception performance

Improve the uplink coverage and

capacity performance 4Antenna reception diversity

need equipment support


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www.huawei.com

Thank You

7-1 WCDMA Radio Network Coverage Planning .ppt

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Transcript of 7-1 WCDMA Radio Network Coverage Planning .ppt