LTE Network Planning.pptx

7/25/2019 LTE Network Planning.pptx

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LTE Basics and Key Technologies


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Part I LTE Basics

Frame Structure & Physical Resource

Physical Channel and Signal

Part II LTE Key Technologies

Part I LTE Basics




Outline


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Evolutionary Process Evolutionary Path o !ireless Technology

LTE becomes the trend of mobile communication technology evolution, during which, multiple

technologies will coexist for a long period of time before they evolve into one single network.

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Type1 frame structure Each1! ms radio frame is divided into "! timeslots or 1! subfra

mes.

Each subframe has " timeslots, !.# ms for each timeslot.

The $L and %L transport is conducted at different fre&uencies.

LTE Radio Frame Structure

LTE supports two types of radio frame structures Type 1, applicable to '%%(Type ", applicable to T%%.

Frame Structure Ty:e1 4 F))

.


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LTE Radio Frame Structure

Frame structure Ty:e#

; T))

Type" frame structure

Each 1! ms wireless frame is divided into two half frameswith the duration of # ms each.

Each half frame is composed of ) timeslots with the duration

of !.# ms and * special +ones %wT-, , $pT-.

The total duration of %wT-, and $pT- is 1 ms, while

the duration of %wT- or $pT- is configurable.

Further

analysis

On the fre&uency domain, the subcarrier interval is 1#/0+. 'or instance, there are 1"!!

subcarriers in the case of "!0+ system bandwidth. On the time domain, each 1ms subframe is divided into several symbols, and there are

guard interval 2 between symbols( there are 13 symbols in 1 ms for regular 2 and 1"

symbols in 1ms for extended 2.


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,:liner

0 1 # " . - ' 6 (

! # ms % - $ $ $ % - $ $ $

1 # ms % - $ $ % % - $ $ %

" # ms % - $ % % % - $ % %

* 1! ms % - $ $ $ % % % % %

3 1! ms % - $ $ % % % % % %

# 1! ms % - $ % % % % % % %

4 1! ms % - $ $ $ % - $ $ %

Coniguration?ormal cyclic :rei9 E9tended cyclic :rei9

)=PTS $P ,:PTS )=PTS $P ,:PTS

! * 1!

1 O'%symbols

* )

1 O'%symbols

1 5 3 ) *

" 1! * 5 "

* 11 " 1! 1

3 1" 1 * 6

" O'%symbols

# * 5

" O'%symbols

) "

4 5 * 5 1

6 1! " 7 7 7

) 11 1 7 7 7

,:lin


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LTE Physical Resource +llocation 4 RE8RB

DLsymbN OFDM symbols

One downlink slot slotT

0=l 1DLsymb = Nl

subcarriers

subcarriers

RBsc

DLsymb NN

Resource block

resource elements

Resource element ),( lk

0=k

1RBscDLRB = NNk

-ubcarrierinterval

2 duration9umber ofsubcarriers

9umber ofsymbols

9umber of:Es

1# /0+

:egular 2 1" 6 )3

Extended2

1" 4 6"

:E ;:esource Element< is the minimum

resource unit( for each antenna port, it indicates

one O'% symbol on the time domain and one

subcarrier on the fre&uency domain.

:= ;:esource =lock< is the resource unit of

service channel resource allocation.

'


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LTE Physical Resource +llocation 4 RE8RB )iagram

6

subcarriers, 1)!k0+

symbols


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)o=nlin< su>rame ?um>er o 5F)/ sym>ols incontrol area

S:ecial su>ram 1@ #

$eneral Su>rame 1@ #@ "

LTE Physical Resource +llocation Control +rea and

)ata +rea

1. %ownlink subframe -ignals in the control area and in the data

area are distinguished by time, and the number of O'% symbols

in the control area can be allocated.

:egular subframe The regular subframe is composed of

two timeslots, including downlink and uplink regular

subframe.

-pecial subframe The special subframe is composed of

three special +ones, namely, %wT-, and $pT-.

". -ignals in the control area and in the data area in the uplink regular

subframeare distinguished by fre&uency.

(

2ontrol area %ata area


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Part I LTE Basics




Part I LTE Basics




Outline


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2hannel type 'unctions

$-20 ;hysical $plink -hared 2hannel< 2arrying uplink service data

$220 ;hysical $plink 2ontrol 2hannel< 2arrying 0>:? information

:>20 ;hysical :andom >ccess 2hannel< -ending preamble information for random access of the$E

2hannel type 'unctions

%-20 ;hysical %ownlink -hared 2hannel < 2arrying downlink service data

=20 ;hysical =roadcast 2hannel< 2arrying broadcasting information

2'@20 ;hysical 2ontrol 'ormat @ndicator 2hannel< @ndicating the number of symbols occupiedby %220 in the same subframe

%220 ;hysical %ownlink 2ontrol 2hannel< 2arrying the downlink scheduling information

0@20 ;hysical 0ybrid >:? @ndicator 2hannel< 2arrying 0>:? information

,:lin< :hysical channel

)o=nlin< :hysical channel

LTE Physical Channel

11


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LTE Physical Channel RE /a::ing o )o=nlin< Physical Channel

%-20 and =20 are mapped onto the data field of subframe.

%-20 and =20 can exist in the same subframe.

1#

O'% symbols

*4 sub7carriers

*4 sub7carriers


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reambleformat

%uration

-e&uence length

! 1ms )*5

1 "ms

)*5

" "ms )*5 ;transmitted

twicedaptive odulationmode

>daptive 2odingefficiency

/a2 more efficient and flexible.

#(


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*y>rid +utomatic Re:eat Reuest *+RD com>ines For=ard Error Correction FECD

and +utomatic Re:eat Reuest +RD% *+R@ =orle an

d accurate rate adGustment the LTE :rocess% FECsends an error correction code from transmitters to correct errors at receivers. +Rsend >2/ or 9>2/ message to feedback the decoding results

*+R

"0


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Fast Scheduling is $rou:ing Scheduling% The >asic aim is to serve ast%

Fast Scheduling

"1

Time4>ased round4ro>in

Flo=4>ased round4ro>in

/a9 C8I

PF Pro:ortional FairD

Each user@ served in order@ gets the same

allocated time in average% 5=ing to dierent

environments o users@ their lo=s dier%

)es:ite the environment dierence@ every user

is ensured to get the same lo= in a certain

order%

The system gives higher :riority to the users

=ho are served at the ma9 C8I%

The system can get the ma9imum Through:ut%

)o not air or users%

This method integrates the scheduling modes

a>ove@ considers the satisaction o most

users@ and ensures a relative high through:ut%

It is a :ractical scheduling mode%


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Documents

LTE Network Planning.pptx