LTE Syst Overview

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Revision RecordCourse Code Product

Product

VersionCourse Version ISSUE

OEA01 LTE / 1.01

Developer/Modifier Time Approver New/Update

Dont Print This Page

Copyright 2010 Huawei Technologies Co., Ltd. All rights reserved. Page0

Yangmuguang 20090311 Mijia New

Liang Jie 20100411 Mijia Update


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LTE System

Overview

www.huawei.com

Copyright 2010 Huawei Technologies Co., Ltd. All rights reserved.


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Objectives Upon completion of this course, you will be able to:

Describe LTE development and features

Outline LTE network architecture

Explain LTE key technologies


Describe LTE protocol and channel

Describe LTE deployment


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Contents1. LTE System Overview

2. LTE Key Technologies

3. LTE Protocol and Channels


.


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.


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1.1 LTE Development1.2 LTE Network Architecture

1.3 LTE Operating Bands and Channel Bandwidths



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3G Long Term Evolution--LTE

HSPA in R5/R6

LTE in R8

DL: ~14.4MbpsUL: ~5.76Mbps

DL: ~42MbpsUL: ~11Mbps

DL: ~141MbpsUL: ~50Mbps

HSPA+ in R7/R8~100 ms~100 ms

~150 ms~150 ms


Year 2002 20042003 2005 2006 2007 2008 2009 2010 2011 2012 or later

3G-WCDMA inR99/R4

GPRS/EDGE

DL: ~384KbpsUL: ~384Kbps

DL: ~144-360KbpsUL: ~144-360Kbps

~70 ms~70 ms

~45 ms~45 ms

~20ms~20ms

LTE is the next step in the evolution of 3GPP Radio Interfaces to deliver GlobalMobile Broadband.


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Drivers for LTE There are at least three major key drivers for LTE mobile

broadband networks:

Demand for higher data-rates

increasing device capabilities, growing mobile data consumption


Maintaining operator profitability while continued cost reduction and

competitiveness.


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LTE Network Architecture E-UTRAN (Evolved Universal Terrestrial Radio Access

Network)



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LTE/SAE Network Architecture - cont.SGSN

GPRS

UMTS

MME

HSS PCRFBTS BSC/PCU

NodeB RNC

S6a

Gb

IuS3

S4

S9S10

User plane

Control plane

Operator ServiceNetwork

EPS (Evolved Packet System)

S6d

SAE


E-UTRAN

cdma2000

Serving GW PDN GWeNodeB

S2a

S1-U

x

S5/8

S1-MME

S12S11

SGi

BTS

Internet

Corporate

Internet

PDSNBSC

A10/A11


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LTE Operating Bands LTE supports both FDD mode and TDD mode.

3GPP defines many bands for LTE.



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LTE Channel Bandwidths LTE must support the international wireless market and

regional spectrum regulations and spectrum availability. To

this end the specifications include variable channel

bandwidths selectable from 1.4 to 20 MHz, with subcarrier


spacing of 15 kHz.Channel bandwidth

BWChannel [MHz]1.4 3 5 10 15 20

Transmissionbandwidth

configuration NRB

6 15 25 50 75 100

NRB is the number of resourceblocks


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.


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LTE Key Technologies

OFDMA: Orthogonal frequency division multiple access

SC-FDMA: Single carrier-frequency division multipleaccess

MIMO: Multiple input multiple output


64QAM


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Multiple access technology in the

downlink: OFDM and OFDMA OFDMA is used as multiple access technology in downlink.

OFDMA is a variant of orthogonal frequency division multiplexing

(OFDM), a digital multi-carrier modulation scheme.

Sub-carriersFFT

5 MHz Bandwidth


OFDM signal represented in frequency and time

Time

Symbols

Guard Intervals

Frequency


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Multiple access technology in the

downlink: OFDM and OFDMA (cont.) OFMDA incorporates elements of time division multiple access

(TDMA).



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Downlink OFDM Implementation

P/SIFFTS/Ps(t)Add

Cyclic

PrefixM M M


n(t)

S/PFFTP/Sr

(t

)

Remove

Cyclic

Prefix

ransm tter

Receiver

Channel

M M


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Downlink OFDM Implementation (cont.)



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Multiple access technology in the uplink:

SC-FDMA The high peak-to-average ratio (PAR) associated with OFDM led

3GPP to look for a different transmission scheme for the LTE

uplink.

SC-FDMA is used in uplink as multiple access technology.



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Comparison of OFDMA and SC-FDMA



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Overview of MIMO MIMO: Multiple Input Multiple Output

Wireless


Transmitterece ver

Channel

N M

Channel Condition Feedback


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What can MIMO provide? Here is a example for 2*2 MIMO.

Wireless Channel

Data Stream 1


ransm er ece ver

Channel Condition Feedback

Data Stream 2


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LTE Multiple Antenna Scheme In downlink LTE can use 2*2 or higher order MIMO to increase

date rate.

In uplink MU-MIMO (multi-user MIMO) can be used to double

uplink capacity.

-


doubled.


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AMC & 64QAM

AMC, Adaptive Modulation and Coding

the radio-link data rate is controlled by adjusting the

modulation scheme and/or the channel coding rate

DL/UL modulations: QPSK, 16QAM, and 64QAM



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2. LTE Key Technologies3. LTE Protocol and Channels


.


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Contents3. LTE Protocol Stacks and Channels

3.1 LTE Protocol Stacks

3.2 LTE Channels

3.3 LTE Radio Frame


Functional Split between E UTRAN and


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Functional Split between E-UTRAN andEPC


Functional Split between E UTRAN and


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Functional Split between E-UTRAN andEPC



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Radio Interface Protocol Architecture



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Radio Interface Protocol Architecture (cont.)


User-plane protocol stack Control-plane protocol stack


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LTE Physical Channel DL

Physical Broadcast Channel (PBCH)

Physical Control Format Indicator Channel (PCFICH) Physical Downlink Control Channel (PDCCH)

Physical Hybrid ARQ Indicator Channel (PHICH)


Physical Multicast Channel (PMCH)

UL

Physical Uplink Control Channel (PUCCH)

Physical Uplink Shared Channel (PUSCH)

Physical Random Access Channel (PRACH)


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LTE Transport Channel Physical layer transport channels offer information transfer to medium

access control (MAC) and higher layers

DL

Broadcast Channel (BCH)

Downlink Shared Channel (DL-SCH)


Paging Channel (PCH)

Multicast Channel (MCH)

UL

Uplink Shared Channel (UL-SCH)

Random Access Channel (RACH)


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LTE Transport Channel Physical layer transport channels offer information transfer to medium

access control (MAC) and higher layers

DL

Broadcast Channel (BCH)

Downlink Shared Channel (DL-SCH)


Paging Channel (PCH)

Multicast Channel (MCH)

UL

Uplink Shared Channel (UL-SCH)

Random Access Channel (RACH)


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LTE Logical Channel Logical channels are offered by the MAC layer

Control Channels: Control-plane information

Broadcast Control Channel (BCCH)

Paging Control Channel (PCCH)


Multicast Control Channel (MCCH Dedicated Control Channel)

Common Control Channel (CCCH)

Traffic Channels: User-plane information

Dedicated Traffic Channel (DTCH): transmission of all uplink and non-

MBMS downlink user data

Multicast Traffic Channel (MTCH): transmission of MBMS services


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Channel Mappings



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Frame Structure FDD frame structure

TDD frame structure



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Resource Grid



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Bandwidth Configuration



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Contents

1. LTE System Overview




.


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LTE SAE

LTE Network Composition



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LTE Network Transport

eNB

SAE GW

/PDN GW

IP/EthernetNetwork

IP/EthernetNetwork

FE/GE

100/1000Base-T, RJ45 100Base-FX/1000Base-X,

SM or MM Fiber, SFP-based connector

IP

MAC

PHY

FE/GE o/e

FE/GE

RNC/BSC


FE/GE

eNB eNB

eNB

FE/GE FE/GE

FE/GE

eNBegacy2G/3G

FE/GE

eNB Daisy-chaining with integrated IP switching

Co-transmission with legacy 2G/3G

eNB

FE/GE

BTS/Node B

Co-transmission for Multi-mode base station

S


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eNodeB 3900 Series

Modularization

RRU/RFU

BBU

eNB

1

2


uniNodeB3

Platform

GSM/TD-SCDMA/WCDMA/CDMA/LTE Unified All-IP Base Station Architecture

Modularization

Using BBU plus RRU and RFU leads to a flexible configuration for Distributed and

Macro.

Multimode

Modularization Supports Different Modes

S th l ti t LTE


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Smooth evolution to LTE

LTE Card

LTE (100M/50M)LTE (100M/50M)

Same band Different band

GSM/HSPA(+)/LTE RRU LTE RRU

GSM / UMTS / HSPA(14.4M/5.76M) /HSPA+(28M/11.5M)

GSM / UMTS / HSPA(14.4M/5.76M) /HSPA+(28M/11.5M)

BBU

RRU Software upgrade

Adding LTE RRU


Investment protection while evolving from GSM/UMTS to LTE

Radio units for GSM/UMTS and LTE are inter-changeable in the same frequency band

Baseband boards in multi-mode BBU are inter-changeable between GSM/UMTS and LTE

Same band Different band

GSM/HSPA(+)/LTE RFU LTE RFU

LTE CardCabinet-based Node B

BBU

Software upgrade

Adding LTE RFUBBU


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Summary

Standardization in the form of 3GPP Release 8

Support for both FDD and TDD.

Flexible spectrum allocation (1.4 ~ 20 MHz). IP-based flat network architecture

Multicarrier-based radio air interface


OFDMA and SC-FDMA

Multi-input multi-output (MIMO)

Adaptive modulation and coding

DL modulations: QPSK, 16QAM, and 64QAM

UL modulations: QPSK, 16QAM, and 64QAM

ARQ within RLC sublayer and Hybrid ARQ within MAC sublayer


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LTE Standard Specifications

Freely downloadable from

http://www.3gpp.org/ftp/Specs/archive/36_series/



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Thank you. .

LTE Syst Overview

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