Performance Analysis of LTE Physical Layer Based on Release 10 New 1

7/24/2019 Performance Analysis of LTE Physical Layer Based on Release 10 New 1

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AbstractDespite their tremendous success over the years,the wireless technologies are still confronted with some of the

critical challenges such as, fading, multipath, and interference andspectrum limitations. To fulfill this, wireless communication

industry worked hard and defined a new air interface for mobilecommunications. That is Long Term Evolution (LTE ),is the

evolution of the niversal !obile Telecommunication "ystem

describes standardi#ation work by the $rd %eneration &artnership&ro'ect .t enhances the overall system performance by increasing

the capacity of the system along with improving spectral

efficiencies while reducing latencies. n order to achieve abovereuirements important changes have been reuired at the physical

layer e.g. new modulation and coding schemes, reduced

Transmission Time nterval (TT) or advanced medium accesstechniues. n this paper, the main ob'ective is to investigate a

downlink and uplink physical layer performance of Long Term

Evolution system.

Keywords: LTE, *+D!, "-+D!, $%&&

./T0*DT*/

LTE stands for 1Long Term Evolution2 is a new

technology that suggests intensifications to prevailing

mobile technologies. LTE is 3% (3th %eneration)technology that focused to afford e4celling features of

service as compare to other technology. LTE is e4tensively

called the adversary technology to 5i!6 because of its

wireless nature and mobile services. LTE technology is

under the phase of growth and advancements to afford

network providers a definite elucidation to shift from $% to

3% technology environment 789. These systems are based

on the first release of LTE, $%&& 0elease :, which was

finali#ed in ;


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+igure B %eneral "ignal "tructure for LTE downlink reproduced by permission of $%&& 7;9

A.LTE Downlink

Due to high spectral efficiency and robust transmission in

presence of multipath fading, the *+D! has been

selected as basic modulation scheme for downlink in LTE

systems. The LTE physical layer specifications are designed

to deal with the bandwidths from B.;>!@# to ;

B. Orthogonal Frequency Division Multiple Access

Data transmission in downlink is based on *+D!, which

is an upcoming techniue to provide an efficient access

over high-speed wireless networks. Cesides, it is adeuate

for broadcasting even in !ultiple-nput !ultiple-*utput

(!!*) scenarios. *+D! acuires high spectral

efficiency in multiuser environments by dividing the total

available bandwidth into narrow sub-bands to be shared by

users in an efficient manner. Different bandwidths are

supported (from B.;> to ;< !@#) keeping subcarrier

spacing unchanged and, as a conseuence, the number of

subcarriers varies accordingly. This technology will offer

broadband wireless access at data rates of multiple !bit?s

to the end-user and within a range of several kilometers 7:9.*+D! at the physical layer, in combination with a

!edium ccess ontrol (!) layer, affords an ideal

resource allocation and Juality of "ervice (Jo") support

for distinct types of services. The *+D! signal used in

LTE comprises a ma4imum of ; k@#. lthough it is necessary for the

mobiles to have capability to be able to accept all ;


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P/SN-DFT Mapping M-IDFTS/P DACADD CP

Detector P/S N- IDFTDe-Mapping/EqualizationM- DFT S/P Remove C P ADC

+igure ;

Transmitter-0eceiver block diagrams for *+D!

The use of "-+D! in LTE is confined to the

uplink because the added time-domain processing would be

a abundant burden on the base station, which has to

manage the dynamics of multi-user transmission "-

+D! can amuse all of the avails mentioned for *+D! in

addition to low &eak verage &ower 0atio (&&0). "imilar

to *+D!, the bandwidth is divided into multiple parallel

subcarriers with cyclic prefi4 in between in order to stayorthogonal to each other and remove nter "ymbol

nterference ("). n "-+D!, the linear combination of

all data symbols that are transmitted at the same time is

modulated to a given subcarrier. n a given symbol period,

all transmitted subcarriers of a "-+D! signal

arecarrying a fundamental of each modulated data symbol.

This is known as a single carrier scheme of "- +D!.

+igure $ Casic block diagram of "-+D! Transmitter 7:9

+igure 3 Casic block diagram of "-+D! receiver 7:9

The basic transmitter and receiver architecture is nearly

identical to *+D!, and it suggests the same degree ofmultipath protection. The "- +D! transmitter comprises

of function blocks similar to *+D!. The block diagram

of "-+D! is shown in +igure $, 3. The input data

stream is first modulated 7=9 to single carrier symbols by

using J&"G, B8-J! or 83-J!. The conseuence

modulated symbols become the inputs of the functional

blocks of "-+D!.

."!LT*/ E/F0*/!E/T

The main core of our study is to measure the

performance of LTE uplink and downlink physical layer

based on 0elease :, A M B


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+igure > LTE Downlink "imulink "tructure

!ultiple4ing by ; ntenna port admits two entries and 3

ntenna port admits B8 entries. 0esource element mapper

map the user use "0 (ell "pecific 0ange) give into the

$%&& standard this transmission carried out over an *+D!

transmission. The figure > shows the results for the default

configuration of the model.

Table B.Layer !apper

Table ; 0esource Element !apping

+igure 8 Error alculation of Two !!* hannel

The "imulink figure 8 shows the error rate calculation of the

two channels at transmitter and receiver of the channel.

omparing the two sets of plots enables you to gauge the

signal separation the !!* receiver achieves, which directly

impacts the &D"@ bit error rate performance.

F. Fenkataramanan, !.Gavitha, Electronics and ommunication, nnaniversity? runai ollege of Engineering?

Thiruvannamalai, ndia.

Co

de

wo

rds

L

a

y

e

r

Mapping

B B

The codeword is mapped to the single layer

B ;

The codeword symbols are split (even?odd)

between the two layers. /ote that this option

is only used when there are 3 antenna ports

; ;

Each codeword is mapped to its own layer.

Coth codeword must have the same length

; $

The first codeword is mapped to the first

layer, while the second codeword is split

(even?odd) between the other two layers./ote that the first codeword must be half the

length of the second codeword, so that each

layer carries the same number of symbols

7B89

; 3

The first codeword is split (even?odd)

between the first two layers, while the

second codeword is split between the

second two layers. Coth codewordNs must

have same length

"pectral C5

(!@#)

B.3 $ > B< B> ; ;> >< => BG@#?

Of=.>G@#)

B;?;3

sed

subcarrier

=;?

B33

B:


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+igure =&ost-*+D! 04 "catter &lots

+igure :&re-Demodulation "catter &lots

F.*/L"*/ /D +T0E 5*0G

This study comprises of absolute reasoning of $%&& LTE 0elease B< "pecifications. Throughput analysis is the ultimate

consideration in any technology of wireless communication. n this study, the ma4imum throughput LTE &hysical Layer

transmission is investigated depending on different scenarios of the physical layer.

The result shows error rate calculation of LTE downlink using B8 J! ,it transmit BB>;


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G/*5LED%!E/T

The uthors are thankful for the !anagement and staff members of runai college of Engineering for their wonderful support

towards &reparation of this &aper.

0eferences7B9 "tefan &arkvall, nders +uruskPr, and Erik Dahlman, Ericsson 0esearch 1Evolution of LTE toward !T-dvanced2 EEE ommunications !aga#ine

Q +ebruary ;

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Performance Analysis of LTE Physical Layer Based on Release 10 New 1