umts coverage planning

8/21/2019 UMTS Coverage Planning

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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

CONFIDENTIAL

www.huawei.com

UMTS Coverage

Planning

ISSUE 4.0

RNP Staff Training Dept.


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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential Page 3

References

UMTS Principle


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After this course, we will：

Understand the purpose of link budget

Understand the uplink budget and itselements.

Understand the downlink budget and its

elements.

Familiarize some technologies for

coverage enhancement

Objectives


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1 Process of UMTS Network Planning

2 Uplink Budget

3 Downlink Budget

4 Coverage Enhancement Technologies

Contents


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1.1 Overview of Radio Network Planning

1.2 Process of Radio Network Planning

Contents


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Definition of Radio Network Planning

This course focus on:

Radio network Planning.

Definition:Network planning means that network elements (NEs) are selected

according to the network target, network evolution requirement, cost,

and the quality request. To design the configuration, and connection

mode between the NEs are determined to facilitate engineering

implementation.Radio Network Planning focus on the elements of radio access

network (RAN).


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Importance of Radio Network Planning in 3G

Importance: The total cost of mobile 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 base stations


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Compare UMTS Network Planning with that of GSM In GSM system, the frequencies for each cell

are planned in order to control the co-frequency

and adjacent-frequency interference.

If the interference requirement is met, thenumber of supported subscribers can be

calculated based on the number of carriers 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.

GSM system mainly offers voice service, and

the GoS and design objective are

correspondingly simple.

f1

f1

f2

f2

f3

f1

f1

f2

f2

f3

f3f1

f2

f1f3

f1

UMTS uses the spread spectrum technology,

1×1 frequency multiplexing without frequency

planning.

The capacity of each carrier in UMTS is "soft"because it is related to factors such as

environment and adjacent-cell interference.

The coverage of the UMTS system is related to

the system load. If the system load increases,

the coverage/quality will decrease.

The UMTS system supports services with

different rate and QoS, including voice service,

and their coverage capability is different. In the

network planning, the system performance

shall be optimized through reasonable planning

and radio resource management.

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1

f1f1

f1

f1f1

f1


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Capacity –Coverage –Quality

Relationship between capacity, coverage, and quality of theUMTS system

The UMTS system is a self-interference system, and its

capacity, coverage, and quality closely related to each other.

Capacity –coverage (e.g. cell breath)

– If the load increases, the capacity and interference will alsoincrease, and the coverage will shrink

Capacity –quality (e.g. outer loop power control)

– The system capacity may increase by lowering the quality of some

connections

Coverage –quality (e.g. AMRC)

– The coverage may increase by lowering the quality of some

connections ÈÝ Á¿

ÖÊ Á¿ ²̧ ̧Ç


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1.1 Overview of Radio Network Planning

1.2 Process of Radio Network Planning

Contents


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Process of Radio 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 be output for mid-stage project and cost

estimation in contract signing


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Process of Radio 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.

Normally, the cell parameters and planning effect should be

checked through simulation, and the output report would be thefinal radio network planning scheme that can guide the project

implementation.


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2 Uplink Budget

3 Downlink Budget


Contents


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Procedure of Coverage Budget Planned area and the environment

features

Coverage probability

Indoor coverage

Cell load

System parameters

Equipment performance

Propagation model

Create link budget

Max cell radius

Site area

Site quantity

Maximum path loss

Total area

Site quantity = Total area / site area

Analyze the customer’s request


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Fundamental Principle

TX

Combiner

Duplexer Feeder

RX

Pout_BS

Lc_BS Lf_BS

Ga_BS NodeB

TX

RX

Pout_UE

Ga_UE UE

Combiner

Duplexer Body

Loss

Fading

Margin

Penetration

Loss


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P a t h L o s s

CableLoss

AntennaGain

NodeB

Sensitivity PenetrationLoss

Radio Link Budget - Uplink

UE Transmit Power

NodeB Antenna Gain

UE Antenna Gain

SHO Gain against

fast fading

SHO Gain against

Slow fadingSlow fading margin

Fast fading margin

Interference margin

Body Loss

Cable Loss

Penetration Loss

Maximum

allowable

path loss

NodeB reception sensitivity

Legend

Antenna Gain

SHO Gain

Margin

Loss


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Algorithm Introduction PL_UL=Pout_UE + Ga_BS + Ga_UE + Ga_SHO – Mpc – Mf

– MI – M_BN – Lp – Lb – S_BS

PL_UL: Maximum propagation loss of the Uplink

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

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)

M_BN: Margin for Background Noise (related to the electromagnetic environment)

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

Lb: Body loss

S_BS: Sensitivity of BS receiver at the connector at the antenna side

(related to factors such as service and multi-path environment, etc)


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Elements of WCDMA Uplink Budget

1. Max Power of TCH

2. Body Loss

3. Gain of UE Tx Antenna

4. EIRP

5. Gain of BS Rx Antenna

6. Cable Loss7. Noise Figure (BS)

8. Required Eb/No (BS)

9. Sensitivity of BS Receiver

10.UL Cell Load

11. Interference Margin

12.Background Noise Level

13.Margin for Background Noise

14.Fast Fading Margin

15.SHO Gain over Fast Fading

16.Minimum Signal Strength

Required17.Penetration Loss

18.Std. dev. of Slow Fading

19.Edge coverage Probability

20.Slow Fading Margin

21.SHO Gain over Slow Fading


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1. Max Power of TCH (dBm) Hardware Para.

For a UE, the maximum power of 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 mobile and the requirement of the operator.

Grade of UE power（TS 25.101 v3.7.0 （2001-06）6.2.1

Power ClassNominal maximum

output powerTolerance

1 +33dBm +1/-3dB

2 +27dBm +1/-3dB

3 +24dBm +1/-3dB

4 +21dBm +2/-2dB


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2. Body Loss (dB) System Para.

For voice service, the body loss is 3 dB.

Because the data service mainly involves reading and video, the UE is

relatively not so close to the body, so the body loss is 0 dB

3. Gain of UE Tx Antenna (dBi) Hardware Para.

Generally, assume that the receiver 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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5. Gain of BS Rx Antenna (dBi) Hardware Para.

Kathrein 741794

Frequency range1710~2170MHz (dual band

for DCS and UMTS)

Polarization +45O, -45O

Gain 18.5dBi

HPBW (1920~2170MHz)Horizontal: 63O

Vertical:6.5O

Electrical tilt Fixed, 2O

Kathrein 741790

Frequency range 1920~2170MHz

Polarization Vertical

Gain 11dBi

HPBW Vertical: 7O

Electrical tilt Fixed, 0O


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Bracket

Upper

jumper

Feeder

Lower

jumper


6. Cable Loss (dB) Hardware Para.

Including the loss of the feeders and all of the connectors.

– Lower jumper

– Connector (between jumper, feeder, cabinet, and lightning

arrester)

– Feeder

– Upper jumper

Other connecter loss is assumed 0.8 dB.

Frequency (Hz)

Feeder 2G 900M 450M

7/8’ 6.1 4.03 2.7

5/4’ 4.5 2.98 1.9


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7. Noise Figure of the receiver (dB) Hardware Para.

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 receiver system

NF = SNR i / SNR o

= (S i / N i) / (S o / N o)

Thermal noise of receiver :

– PN = K*T*BW*NF= -174 (dBm/Hz) + 10lg(3.84MHz / 1Hz) + NF(dB)

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

G1

NF1

G2

NF2

Gn

NFn1211

21

...

1...

1

n

nTotal

GGG

NF

G

NF NF NF


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7. Noise Figure of the receiver (dB) (Cont.)

To calculate the Noise Figure of a receiver, normally only the first

two or three components need to be considered.

NodeB f

NodeB f f

f

NodeB f TMAWithout Total

NF NF

NF NF NF

G

NF NF LinerValue NF

)1(

1)( _ _

In case if no TMA:

Feeder NodeB Antenna

G_NodeBNF_NodeB

GnNFn

G_fNF_f

)()(

)()()( _ _

dB NF dBer LossofFeed

dB NF dB NF dB NF

NodeB

NodeB Feeder TMAWithout Total


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7. Noise Figure of the receiver (dB) (Cont.)

f tma

nodeB

tma

f

tmaTMAWithTotal GG

NF

G

NF NF LinerValue NF

11)( _ _

In case if TMA is used:

G_f

NF_f

G_NodeB

NF_NodeB

G_tma

NF_tma

Feeder NodeB

Antenna

TMA

Normally, the NF of the TMA is very small (TYP 1.5dB), and the gainis high (TYP 12dB or 24dB). So we can get a lower total NF of the

receiver system with TMA than if without TMA. Thus we could get a

better receiver performance.


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8. Eb/No Required (dB) System Para.

Obtained through link simulation. It is variational according to the

service and the signal environment:

– Mode of the receiver diversity

– Multi-path environment

– Bearer type (service)

9. Sensitivity of BS Receiver (dBm)

Sensitivity of Receiver (dBm)

= PN(dB) + Eb/No Required (dB) – Processing Gain

= -174 (dBm/Hz) + 10lg(3.84MHz / 1Hz) + NF(dB) + Eb/No (dB)

- 10lg[3.84Mcps/Rb(bps)]= -174 (dBm/Hz) + NF (dB) + 10lg[1000 * Rb (kbps)] + Eb/No (dB)


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10. Uplink Cell Load Network Target

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

The higher the uplink load, the higher the uplink interference

If the uplink load is approach 100% (NEVER reach in the live network),

the uplink interference will approach infinite, then the corresponding

capacity will be the maximum capacity

N

j j j

N

jUL

v R

W

EbvsNo

i Li11

111

111


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UL

N

j N

TOT

L P

I NoiseRise

1

1

1

1

1

50% Load — 3dB

60% Load — 4dB

75% Load — 6dB

11. Uplink Interference Margin (dB)


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12. Background Noise Level (dBm)External electromagnetic interference sources:

– Wireless transmitters (GSM, microwave, radar, television

station, and so)

– Automobile ignition

– Lightning – …

For a specific area, it is recommended to estimate the local

interference through frequency spectrum test


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13. Margin for Background Noise Level (dB) Environment Para.

Suppose the thermal noise of the receiver is P dBm, the

background interference level is N dBm, then received signal

should be larger than before to overcome the noise, so the

margin for the background noise should be:

Margin for Background Noise =

10log (10P/10 + 10N/10) dBm - P dBm

In link budget tool, if we don’t consider the

environment interference, we can set the

background noise to a sufficient lower value

lower than the PN, e.g. -100dBm. Thus the

Background Noise Margin is 0dB.


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14. Fast Fading Margin (dB)System Para.

Also is called Power Control Margin

In the link budget, the demodulation performance of the

receiver is the simulation result based on the assumed ideal

power control.

In an actual system, the transmitter power is limited, this willtake non-ideal factors in the closed loop power control

So some power should be reserve for fast power control. It is

the fast fading margin.


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15. SHO Gain over Fast Fading (dB) System Para.The soft handover gain includes two parts:

– Multiple unrelated soft handover branches lower the required

margin for fading, which results in multi-cell gain

– Gain for the link demodulation of the soft handover –macro diversity

combining gain

The SHO Gain over Fast Fading refer to the Macro Diversity

Combination gain and it reduces the request for fast fading

margin

This value is obtained through simulation. Typically it is 1.5 dB.


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16. Minimum Signal Strength Required (dBm)The required minimum signal level is:

Receiver Sensitivity + the losses and margins – the gains

Minimum Signal Strength Required

= Receiver Sensitivity (dBm) + Body Loss (dB)

+ Interference Margin (dB) + Background Noise Margin (dB)+ Fast Fading Margin (dB)

- Gain of Antenna (dBi) - SHO Gain over fast fading (dB)


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17. Penetration Loss (dB) Environment Para.

Indoor penetration loss refers to the signal level difference between

the average strength near the wall outside the building and that of

inside the building.

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

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

loss is subject to the lognormal distribution.

It is uneconomical to provide good indoor coverage by an outdoor

base station. Inside the building it should be covered by special

indoor coverage system.

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 tenders.


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18. Std. dev. of Slow Fading (dB) – Std. dev. of indoor path lossSuppose the standard deviation of the path loss outdoor is X

dB, that of the Penetration Loss is Y dB, the standard

deviation of path loss indoor can be get by sqrt( X2 + Y2 )

Environment Para.


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Elements of WCDMA Uplink Budget 19. (Cell) Edge coverage Probability Coverage request

If the transmit power of a UE hits the maximum threshold, but still cannot

overcome the path loss to guaranty the lowest receive level, the radio link will

drop or the UE will fail to access the network.

If the designed signal level at the edge of a cell equals to the Minimum Signal

Strength Required, the actual measurement result will obey the normal

distribution.

X

–This means there is a probability of 50% that the UE cannot access the network.

–If we design a smaller cell radius, the user will be nearer to the station, so the signal

will be better and the probability to access the network will be higher.


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20. Slow Fading Margin (dB) Envn. Para. due to Edge coverage Probability

Slow Fading Margin (dB) =

NORMSINV (required edge coverage Probability) × Std. dev. of Slow Fading (dB)

Edge Reliability:50%

Edge Reliability:75%

Key point: Property of normal distribution


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21. SHO Gain over Slow Fading (dB)

The soft handover gain includes two parts:

– Multiple irrelevant soft handover branches lower the required

margin for fading, which results in multi-cell gain

– Gain for the link demodulation of the soft handover –macro

diversity combination gain

The SHO Gain over Slow Fading refers to the multi-cell gain

Obtained through simulation


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Summary: path loss at the edge of a cell

Based on the maximum path loss allowed by the link, the path

loss at the 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)

+ SHO Gain over Slow Fading (dB)

- Minimum Signal Strength Required (dBm)

- Penetration Loss (dB)

- Slow Fading Margin (dB)


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Summary of Uplink budget

UE Power – Body Loss

＋Ga_UE_Antenna

Sensitivity of Receiver - SHO Gain over fast fading

- Gain of Antenna + Fast Fading Margin + Body Loss +

Interference Margin

+ Margin for Background Noise

f(edge coverage Probability)

* Std. dev. of Slow Fading

EIRP + SHO Gain over Slow Fading - Slow Fading Margin - Minimum Signal Required

Sensitivity of Receiver = PN + required Eb/No – Processing Gain

PN = 10lg ( K*T*B*NF ) = -108 (dBm/3.84MHz) + NF (dB) ;

NF is the equivalent noise figure of the receiver at the antenna connecter

Processing Gain = 10lg[3.84Mcps/Rb(Kbps)]

So the Sensitivity of Receiver =

174 (dBm/Hz) + NF (dB) + 10lg[Rb (bps)] + Eb/No (dB)

Margin for Background Noise

= 10log (10P /10＋10 N/10) dBm－P dBm

standard deviation of path loss outdoor : X dB,

standard deviation of Penetration Loss: Y dB,Std. dev. of Slow Fading = Sqrt(X2 + Y2)

Maximum Path Loss

- Penetration Loss


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2 Uplink Budget

3 Downlink Budget


Contents


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Radio Link Budget - Downlink

NodeB Transmit Power

NodeB Antenna Gain

UE Antenna Gain

SHO Gain against

fast fading

SHO Gain against

Slow fadingSlow fading margin

Fast fading margin

Interference margin

Body Loss

Cable Loss

Penetration Loss

Maximum

allowable

path loss

UE reception sensitivity

Legend

Antenna Gain

SHO Gain

Margin

Loss

P a t h

L o s s

CableLoss

AntennaGain

NodeB

Sensitivity

PenetrationLoss


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Algorithm PL_DL=Pout_BS – Lf_BS + Ga_BS + Ga_UE + Ga_SHO

–Mpc – Mf – MI – Lp – Lb – S_UEPL_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 UE

Ga_SHO: Gain of soft handoverMpc: Margin for fast power control

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

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

Lp: Penetration loss of a building (for indoor coverage only)

Lb: Body lossS_UE: Sensitivity of UE receiver (related to factors such as service

and multi-path condition)


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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 Load

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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Max Power of TCH (dBm)

All the users in the same cell share the power of the transmitter

simultaneously. So for each user, the UE can only get all of the total

power. We can only set a maximum power for each channel.

General rule: Set different maximum power for different channels,

to ensure the coverage of the main service is the same as that of

the pilot channel.

ChannelDL Max Power per Ch

(typical)

Pilot Channel 33dBm

12.2K Voice 30dBm

64K VP 36dBm


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Downlink Cell Load

Downlink cell load factor is defined in two ways:

1. Downlink cell load factor at the receiver:

This definition is similar to that of the uplink cell load:

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

and the higher the downlink interference.

– When the downlink cell load approach 100% , the corresponding

capacity is the limit capacity of the downlink.

2. Downlink cell load at the receiver: The ratio of the current cell transmit

power 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

j j j DL vW

R No Ebi

1

/1


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Downlink Interference Margin (dB)

Noise rise on downlink:

If define the load factor according to the downlink transmitter, the

formula will be:

In link budget tool – α(j) is orthogonality factor on edge of the cell. It is related to environment, cell radius

and can be obtained by simulation.

– f(j) is interference factor on edge of the cell. 1.78 (=2.5dB) is a worst value.

),0()]()([1)( max

jCL N

P j f j j NoiseRise

o

DL

N

n jCL

nCL

No jCL

P j f j

No

jCL P j f j No

No

j I

nTxCIR

j NoiseRise

CCH

DL

TX TOT

1),0(

),0(

),0(1

)]()([

),0(/)0()]()([)(

])( _ [1

)(


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2 Uplink Budget

3 Downlink Budget


Contents


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Tower Mounted Amplifier (TMA)

TMA

Located just under the antenna

Low noise amplifier

Helps to improve the uplink receive

sensitivity and enhances the uplink

coverage

About 0.7dB loss in the downlink


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Academic calculation about TMA

Academic calculation about TMA improve the uplink receive sensitivity


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The example of academic calculation about TMA improve

the uplink receive sensitivity

Example of academic calculation about TMA

Equipment Noise Figure Gain

TMA 1.45 12

7/8"Cable30m + 0.6dB Connector Loss 2.433 -2.433

NodeB 2.2

Receiver Chain Noise Figure

Without TMA: 2.433+2.2 dB = 4.633 dB

With TMA: 1.57 dB

4.633-1.57 = 3.063 dBSo get a 3.063dB gain for uplink when using TMA


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4-Antennas Reception Diversity

Two ways to realize 4-Antennas reception

diversity Two Cross-polarization antennas

Four antennas

4-Antennas reception diversity helps to

improve the performance of the uplink

receiver

Improve the uplink coverage/capacity

To realize 4-Antennas reception diversity,

there is a requirement for the NodeB


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4RxDiv principle –diversity gain

Resist fast fading

Correlation combination

Gain relates to multi-path,

service, speed, antenna

performance

2RxDiv－> 4RxDiv

Reduce the requirement of

Eb/No


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Area ChannelEb/No

improvementCapacity-based

gainCoverage-based

gain

High-densityurban area

TU3 2.4 1.73 1.37

Common urbanarea

TU3 2.4 1.73 1.37

Suburb RA120 2.5 1.77 1.39

Rural area RA120 2.5 1.77 1.39

Compared with a double-antenna reception diversity, 4-antenna

reception diversity requires lower Eb/No Gain of 4-antenna reception diversity (compared with double-antenna

reception diversity)


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umts coverage planning

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