LTE Link Budget (Ejemplo)

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IT

ITU/U/BDT BDT Arab RArab Regional Wegional Worksorkshop on “hop on “4G 4G Wireless Wireless Systems” Systems” --TTunisunisia 2ia 2010100

“4G

“4G Wireless

Wireless Systems”

Systems”

L

TE

Technology

Session

Session 5

5 :: LLTE

TE Technology Perofrmance

Technology Perofrmance

S

Sppeeaakkeerrs s MM.. Lazhar BELHOUCHETLazhar BELHOUCHET

.

D

Daatte e 227 7 – – 2299 January 2010January 2010

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IT

Agenda

–

FrequencyFrequency BandsBands andand TypicalTypical deploymentdeployment areasareas

–

LayerLayer 11 PeakPeak BitBit RatesRates

–

TerminalTerminal CategoriesCategories

–

ReferenceReference SensitivitySensitivity

–

LinkLink BudgetsBudgets

–

PropagationPropagation modelmodel

–

DownlinkDownlink linklink budgetsbudgets

–

ComparisonComparison betweenbetween GSM/HSPA/LTEGSM/HSPA/LTE

–

LatencyLatency

–

LLTETE RefarmingRefarming toto GSMGSM SpectrumSpectrum

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–

CapacityCapacity DimensioningDimensioning

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IT

Agenda

–

FrequencyFrequency BandsBands andand TypicalTypical deploymentdeployment areasareas

–

LayerLayer 11 PeakPeak BitBit RatesRates

–

TerminalTerminal CategoriesCategories

–

ReferenceReference SensitivitySensitivity

–

LinkLink BudgetsBudgets

–

PropagationPropagation modelmodel

–

DownlinkDownlink linklink budgetsbudgets

–

ComparisonComparison betweenbetween GSM/HSPA/LTEGSM/HSPA/LTE

–

LatencyLatency

–

LLTETE RefarmingRefarming toto GSMGSM SpectrumSpectrum

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2

–

CapacityCapacity DimensioningDimensioning

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IT

Introduction

•

• Performance

Performance evaluation

evaluation :: LLTE

TE capabilities

capabilities from

from the

the end

end user’s

user’s

and

and from

from the

the o

o er

erat

ator’

or’ss oint

oint of

of view

view

•

• The

The operator

operator is

is interested

interested in

in the

the network

network efficiency:

efficiency:

–

howhow manymany customerscustomers cancan bebe served,served,

–

howhow muchmuch datadata cancan bebe providedprovided andand howhow manymany basebase stationstation sitessites areare required.

required.

•

• e

e en

en user

user ap

app

p ca

cat

t on

on per ormance

per ormance e

ep

pe

en

n ss on

on ::

–

availableavailable bitbit rate,rate,

–

seamlessseamless mobilitymobility

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ITU/BDT Arab Regional Works hop on “ 4G Wireless Systems” - Tunis ia 2010

Frequency Bands

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Frequency Bands : Typical deployment areas

•

Europe:

– Band 7:The 2.6 GHz auctions have been running in a few countries during 2007 and 2008, and continue during 2009/2010.

– Band 8:is currently used mostly by GSM. The band is attractive from a coverage point of view due to the lower propagation losses. The band can be reused for LTE or for HSPA.

– Band 3: is also used by GSM, but in many cases Band 3 is not as heavily used by GSM as Band 8. That makes refarming for LTE simpler.

–

Digital dividend

•

USA: Bands 4, 12, 13, 14 and 17. Bands 2 and 5 can be used for LTE refarming.

•

Japan : Bands 1, 9, 11 and 18.

•

ÆLTE deployments globally will use several different frequency bands from the start.

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LTE Technolo Perofrmance Evaluation

PERFORMANCE EVALUATION

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Layer 1 Peak Bit Rates

s SubCarrier of Number Hz bits ms SubFrame per symbols of Number s Mb rate bit Peak *( )* 1 ] / [ =

• control and reference signal overheads:

– PDCCH: takes one symbol out of 14 symbols. That is the minimum possible PDCCH

=

. . .

– Downlink Reference Signals (RS) depend on the antenna configuration :Single stream transmission uses 2 RS out of 14 in every 3rd sub_‐carrier, 2 × 2 MIMO 4

. . . .

– Other downlink symbols Overhead: synchronization signal, PBCH, PCFICH, and one group of PHICH. The overhead depends on the BW ranging from below 1% at 20

. .

– Uplink reference signals take 1 symbol out of 7 symbols resulting in an overhead of 14.3% = 1/7.

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Layer 1 Peak Bit Rates – Cont.

BW RB/Sub‐carriers Modulation and coding Bits/ symbol MIMO usage 1.4 MHz 6/72 3.0 MHz 15/180 5.0 MHz 25/300 10 MHz 50/600 15 MHz 75/900 20 MHz 100/1200 QPSK 1/2 1 Single stream 0.9 2.2 3.6 7.2 10.8 14.4

16QAM 1/2 2 Single stream 1.7 4.3 7.2 14.4 21.6 28.8

64QAM 3/4 4.5 Single stream 3.9 9.7 16.2 32.4 48.6 64.8

64QAM 3/4 9 2 × 2 MIMO 7.8 19.4 32.4 64.8 97.2 129.6

64QAM 1 1 12 2 × 2 MIMO 10.4 25.9 43.2 86.4 129.6 172.8

64QAM 1/1 24 4 × 4 MIMO 20.7 51.8 86.4 172.8 259.2 345.6

Downlink eak bit rates (Mb s)

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Layer 1 Peak Bit Rates – Cont.

BW RB/Sub‐carriers

and coding symbol

. 6/72 . 15/180 . 25/300 50/600 75/900 100/1200 QPSK 1/2 1 Single stream 0.9 2.2 3.6 7.2 10.8 14.4 16QAM 1/2 2 Single stream 1.7 4.3 7.2 14.4 21.6 28.8 16QAM 3/4 3 Single stream 2.6 6.5 10.8 21.6 32.4 43.2

. . . .

64QAM 3/4 4.5 Single stream 3.9 9.7 16.2 32.4 48.6 64.8 64QAM 1/1 6 Single stream 5.2 13.0 21.6 43.2 64.8 86.4

Uplink peak bit rates (Mbps)

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Terminal Categories

Category 1 Category 2 Category 3 Category 4 Category 5 Peak rate downlink (approximately) 10 Mbps 50 Mbps 100 Mbps 150 Mbps 300 Mbps Peak rate uplink (approximately) 5 Mbps 25 Mbps 50 Mbps 50 Mbps 75 Mbps Max bits received within TTI 10 296 51 024 102 048 149 776 299 552 Max bits transmitted within TTI 5 160 25 456 51 024 51 024 75 376

RF bandwidth 20 MHz 20 MHz 20 MHz 20 MHz 20 MHz

Modulation uplink 16QAM 16QAM 16QAM 16QAM 64QAM

Receiver diversity Yes Yes Yes Yes Yes

MIMO downlink Optional 2 × 2 2 × 2 2 × 2 4 × 4

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