07 FDD LTE Radio Link Budget 75

FDD-LTE Radio Link Budget

Contents 

FDD-LTE link budget overview



FDD-LTE UL Link budget



FDD-LTE DL Link Budget



Cell radius and areas

The process of FDD-LTE network planning

Link budget input and output Coverage Inputs •

•

Area to be covered

Targeted service at cell edge

Coverage Outputs •

Indoor penetration level

Network Information •

Incumbent network info •

•

LTE Frequency

LTE Maximum bandwidth

Link Budget RF Planning

•

Cell Range

Legacy Site Reuse

•

Number of Sites

•

Normal Link budget requirements

UL cell range DL throughput at cell range

1

Request UL cell edge throughput

•

2

Request DL cell edge throughput

•

3

Request UL and DL cell edge throughput

•

DL cell range UL throughput at cell range

•

UL cell range DL cell range Limited link and cell range

•

•

•

4

Request fixed cell radius

UL cell edge throughput DL cell edge throughput

•

•

Link budget model

Request cell edge throughput

Request cell range

Cell range

Throughput at cell edge

Shannon formula

C=W*log10(1+S/N)

Coverage

Capacity

Contents 

FDD-LTE link budget overview



FDD-LTE UL Link budget



FDD-LTE DL Link Budget



Cell radius and areas

UL Link budget process Request cell edge throughput

Assign RB # TBS & MCS

MIMO Conf.

SINR  Rx receive sensitivity

Interference margin

MAPL Cell range

Other parameters

UL link budget Methodology

MAPL= Pmax  – Receive Sensitivity  – Losses  – Margins +Gains

UL Link budget Request cell edge Throughput

Rx receive sensitivity

Example of  512kbps and Dense urban area

 Assigned RB number  20kbps

64kbps

128kbps

256kbps

384kbps

512kbps

768kbps 1024kbps

RB

1

2

3

6

8

10

15

18

MCS

1

2

2

3

3

3

3

4

TBS

24

72

144

328

440

568

872

1288

Number of Resource Blocks 

For a given MCS the TBS is given different numbers of  resource blocks RB number 

TBS Table

Modulation & Coding Scheme 

This determines the Modulation Order which in turn determines the TBS Index.

MCS Table

TBS and MCS 

For 512kbps,If BLER=10%, TBS>568bit

512kbps 10 RB

MCS

MCS vs RB

25 20 15

MCS 3

10 5 0

512kpbs

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15 16 17 18 19 20 21

RB number 

 Assign RB number  number 

-100 Receive Power

-105

512kpbs

SINR

-110 -115 -120 -125 1

2

3

4

5

6

7

8

9

10

11

12

13

10RB is assigned for 512kbps

14

15

16

17

18

19

20

21

RB number 

SINR 



SINR Target depends on: 

eNode-B equipment performance



Radio conditions (multipath fading profile, mobile speed)



Receive diversity (2-way by default or optional 4-way)



Targeted data rate and quality of service



The Modulation and Coding Scheme



Max allowed number of HARQ transmissions (Maximum of 4 on UL)



HARQ BLER target (10% considered by default)

Derived from link level simulations or better by equipment measurements (lab or on-field measurements)

SINR MIMO Conf.1T2R MCS 3 SINR:-1.79dB

MIMO Conf.1T4R

 Assign RB number  number 

RB number 

64kbps

128kbps

256kbps

384kbps

512kbps

1024kbps

RB

2

4

7

8

10

17

MCS

2

1

2

3

3

4

SNR target(1*2)dB

-0.3

-2.28

-2.38

-1.63

-1.79

-1.19

SNR target(1*4)dB

-4.6

-6.1

-6.18

-5.46

-5.6

-4.96

Rx receive sensitivity Own cell signal

Request SNR 

 NF  Noise Power 

Reference Sensitivity  Noise Power+ Power+ Noise Figure +SNR  ＝

Dense Urban

Thermal Noise 

Thermal noise power spectrum density

Noise power spectrum density=k*T Where K

Boltzmann constant ——1.381

T

Kelvin temperature

Assume T=290K  17 

10-23

J/K)

K

Noise power spectrum density)=-174dBm/Hz

Thermal noise power 

Noise power= Noise power spectrum density *Bandwidth Assume bandwidth=20MHz Effective bandwidth =18MHz Noise power (dB)=-174dBm/Hz+10log(18 106) =-174+72.6=-101.4dBm

Receiver sensitivity Reference Sensitivity

NF +10log(No) +10log(Bandwidth) +SNR 

D

Urban

Morph

S

R 

Highway

kbps

512

512

384

128

256

Assign # Resource Blocks

# 

10

10

6

3

4

Used Bandwidth

KHz

1800

1800

1080

540

720

eNode-B Noise Figure

dB

3

3

3

3

3

-174.0

-174.0

-174.0

-174.0

Cell Edge User Throughput

No dBm/Hz -174.0 SINR Request eNode-B Sensitivity

dB

-4.0

-3.8

-2.5

-2

-1.8

dBm

-112.4

-112.2

-113.2

-115.7

-114.2

UL interference margin

UL interference margin

UL Interference Margin



The Interference Margin is the interference rise over that of thermal noise due to other cell interference



Typical IM target considered in LTE link budgets is 3dB

Own cell signal

Required Received Signal Request SINR  Interference level

Other cell interference

Noise

Interference Margin

UL Interference Margin

30

   )    B25    d    ( 20   e   s    i 15    R   e 10   s    i   o 5    N

50% cell load 3dB Noise Rise

0

0

10

20

30

40

50

60

70

Cell Load (%)

80

90

10 0

eNode B antenna gain

eNode B antenna gain

eNode B antenna gain 

General antenna selection recommend for 2 way receive Based on the engineering experience



Antenna Gain is about 18dBi



Horizontal Half-power Beam Width is about 65



Vertical Vertical Half-power Beam Width is about 7



Adjust Electrical Down tilt is by hand or by optional RCU (Remote Control Unit)



For the Polarization in dense urban, urban and suburban is X pol, rural areas can use vertical pol.

Some case to cover highway or railway, rai lway, it can select higher gain and narrower beam width antenna, (for example 21dBi and beam width is about 33 )

Four Antenna configuration way Case1

Case2

Case3

Four Antenna configuration way

Case2

Four Antenna configuration way

Case3

Four Antenna configuration way

Link level simulaiton

Four Antenna configuration way ural Highway Dense Urban Urban Suburban R ural Cell Edge User Throughput kbps 512

512

384

128

256

Num. of Tx antenna

#

1

1

1

1

1

Num. of Rx antenna

#

4

4

4

4

4

Assign # Resource Blocks

#

10

10

6

3

4

MCS

#

3

3

4

2

4

TBS

bit

568

568

408

144

256

Case1 SINR Request

dB

-7.2

-7.0

-6.8

-6.5

-5.6

Case2 SINR Request

dB

-5.4

-4.5

-3.3

-4.4

-3.8

Case3 SINR Request

dB

-4.0

-3.8

-2.5

-2

-1.8

SINR Request

Four Antenna configuration way

D Morph

Dense Rural

Urban S

R 

Highway

km

0.50

0.71

2.32

9.77

12.30

km

0.44

0.61

1.83

8.45

10.86

km

0.40

0.58

1.74

7.17

9.47

urban, Urban and Suburban use Case3

and Highway can use Case2 if the situation permitted

Coverage

Cable & connector losses

Cable & connector losses

Cable and connector loss Each Connector Insertion Loss typical 0.05dB

Connector 1/2 in Jumper

The loss depend on the length of cable

The loss less than 0.5dB

7/8in cable optical fiber

Assume: 7/8in cable 50m 1/2in cable 6m+4 connecter

700MHz:2dB 2.6GHz:4dB

TMA gain

TMA gain

TMA gain TMA also called Mast Head  Amplifier (MHA) (MHA)  Impact on link budget  Reduces global Noise Figure  Compensate cable losses  The gain on link budget related to: 

   



Cable loss eNode NF TMA amplifier gain TMA NF

0.5 dB additional insertion loss on DL

 Antenna

Jumper  Cable

Dual TMA Duplexer

LNA Duplexer 

Duplexer 

LNA

Feeder 

Duplexer 

Jumper  Cable

TX / RX

eNode-B

TXdiv / RXdiv

Shadowing margin

Shadowing margin

Shadowing Margin

Shadowing Standard Deviation

10 dB

8 dB

7 dB

6 dB

Cell Area Coverage Probability

95%

90%

95%

90%

95%

90%

95%

90%

Cell Edge Coverage Probability

87.7 %

77.7 %

86.2 %

75.1 %

84.9 %

73.3 %

83.9 %

70.9 %

Shadowing Margin

11.7 dB

7.7 dB

8.7 dB

5.4 dB

7.2 dB

4.3 dB

5.9 dB

3.3 dB



Dense urban, Urban and Suburban Shadowing Standard Deviation is 8dB



Rural and Highway Shadowing Standard Deviation is 6dB

Handoff gain

Handoff gain

Hard handover Gain 

The hard handover gain is the value to reduce the shadowing margin



The hard handover gain is related to handoff hysteresis thresholds, connection delays, coverage probability targets and shadowing standard deviations



The simulation result shows that the hard handover gain is about 2~4dB

Penetration and body loss

Penetration and body loss

Penetration Penetratio n loss

Environment

Penetration Margin (dB)

Dense Urban  – Deep Indoor

20

Urban - Indoor

17

Suburban - Indoor

14

Rural  – In car

8 Related with Operator’s strategy

Body loss 

VoIP service：3dB



Data service：0dB

Related with service

UE gain and Tx power 

UE Antenna gain and Tx power

UL Link budget

MAPL= Pmax  – Receive Sensitivity  – Losses  – Margins +Gains 1 2 3 4 5

6 7 8 9 10 11 12

MAPL=12-1-2+3-4+5-6+7-8-9-10+11 Propagation model

Propagation model 

Cost231-Hata (UP to1.5GHz) Path Loss (dB) = 46.3 + 33.9 x log (f)  – 13.82 x log(hb) – a(hm) +[44.9  – 6.55 x log (hb)] x log (R) + Kc



Okumura-Hata(150 MHz to 1500 MHz ) Path Loss (dB) = 69.55 + 26.16 x log (f)  – 13.82 x log(hb) – a(hm) +[44.9  – 6.55 x log (hb)] x log (R) + Kc Where f

= Frequency of Transmission

hb

=Base station Antenna Height (m)

hm R

MHz

=UE Antenna Antenna Height (m) , 1.5m is normal.

= Distance between the base and UE (km)

Kc

= Morphology correction factor 

a(hm)

:Ant height correction factor = (1.1 x log (f)  –0.7) x hm - (1.56 x log (f)  –0.8)

Inter site distance and coverage area

Inter site distance and coverage area

UL Link budget

Contents 

FDD-LTE link budget overview



FDD-LTE UL Link budget



FDD-LTE DL Link Budget



Cell radius and areas

Different of UL and DL link budget Own cell signal Adjacent cell interference

UL

DL

Noise

Required Received Signal Request SINR 

DL can not use same LB method With UL

DL link budget Methodology

DL Link budget character 

.

1 1 5.5 0 00 E

1 1 5.5 1 67 E

 3    8   .  8   1    6   7   N

      N       7       6       1       8  .       8       3

 3    8   .  8    0    0    0   N

      N       0       0       0       8  .       8       3

.

1 1 5.5 0 00 E

1 1 5 .5 1 6 7E

.  .

Assume: Adjacent site power load: 50% Geometry factor at cell edge :3dB

   )    t    B   a   d   e   (   s   e    i   r   g   e   d   s   e    i    l   o   l    N  e   c

Dense urban cell range (km)

DL link budget approach Cell range Other parameters

MAPL

MIMO Conf.

SINR 

G factor

Assign RB #

MCS&TBS Cell edge throughput

Request cell range

Throughput at cell edge

DL Link budget

Request cell range

DL Link budget MIMO configuration eNode B Tx Power Same with UL

DL shadowing Margin 

Shadowing Margin on signal Shadowing Standard Deviation

8 dB

6 dB

Cell Area Coverage Probability

95%

90%

95%

90%

Cell Edge Coverage Probability

86.2%

75.1%

83.9%

70.9%

Shadowing Margin

Shadowing Standard Deviation 8dB

8.7 dB 5.4 dB 5.9 dB 3.3 dB

95% signal margin 8.7dB

DL Link budget

Adjacent cell power loading

 Adjacent Tx Power load Assume: Cell range : 500m Geometry factor at cell edge :3dB

   l    l    )   e   c   B    d    t    (   a   e    R  g    N   d    I   e    S

Adjacent cell Rx Power load(%)

 Adjacent cell Rx Power load(%)

0

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

SINR @cell edge(dB)

7.24

4.11

2.31

1.04

0.06

-0.74

-1.42

-2.00

-2.52

-2.98

-3.39

DL Link budget

Geometry at cell edge

Geometry factor  Not related to ISD

Geometry 

Rx Power Serving Site

 Rx Power Adjacent Site All

System level simulation

8 9

19 18

10

2 7

3 11

17 6 16

1

4 12

5 15

13 14

5%CDF is cell edge G factor is -3dB

DL Link budget

SINR at cell edge

SINR

   l    l    )   e   c   B    d    t    (   a   e    R  g    N   d    I   e    S Assume: Adjacent site power load: 50% Geometry factor at cell edge :3dB

Dense urban cell range (km)

DL Link budget

DL throughput at cell edge

DL Link budget 2T2R 2T02R SFBC RB20 CFI1 CFI1 SCME UrbanMicro UrbanMicro 3km/ hr Pol 3. 3GHz 10 MCS0 MCS1 MCS3

-1

BLER >=7%

10

MCS5 MCS7 MCS9

       R        E        L        B

MCS12

-2

10

MCS14 MCS16 MCS18 MCS20 MCS22

-3

10

MCS25 MCS27 MCS28

-4

10

-10

-5

0

SINR >=-0.22dB

5 10 SNR(dB)

15

20

25

DL Link budget 100 RB

MCS 5

Throughput= TBS/TTI*(1-BLER)

DL Link budget

DL Link budget approach Request cell edge throughput Assign RB # TBS& MCS MIMO Conf.

SINR 

MAPL

Other parameters

Cell range

Request cell edge throughput

Cell range

DL Link budget

How to get Assign # RB?

 Pathloss AtCellEdge  AtCellEdge 

TxPower  EIRP   1  SINRT  arg et  G AtCellEdge  AtCellEdge SINRT  arg et   NoisePower   NoisePower 

Contents 

FDD-LTE link budget overview



FDD-LTE UL Link budget



FDD-LTE DL Link Budget



Cell radius and areas

Limited link UL cell radius

Cell radius based on coverage

DL cell radius

Cell radius based on capacity

Final cell radius

Cell range and inter site distance SOmin=2.60*R 2

R

S3Sector=1.95*R 2

Glossary 

RB: Resource Block



TBS: Transport Block Size



MCS: Modulation & Coding Scheme



SINR: Signal to Interference plus Noise Ratio



MIMO: Multiple Input Multiple Output



MAPL: Maximum Allowable Path Loss



TMA: Tower Amplifier 



BLER: Block Error Ratio



HARQ: Hybrid automatic repeat request



SNR: Signal to Noise Ratio



NF: Noise Figure



ISD: Inter-station Distance



CDF: Cumulated Distribution Function



TTI: Transmission Time Interval