4G Mobile Technologies

An IEEE Comsoc Indonesia Chapter Lecture

@kuncoro

Mobile Communications

Critical Factors for Wireless Development

Web 2.0

Growth of Advanced Mobile Devices

Data Rate Requirements100

10

1

0.1

0.01

0.001

Peak

dat

a ra

te tr

ansm

issio

n (M

b/s)

GSMGPRS

CDMA-2000EDGE CDMA-1X

W-CDMAEVDO

EVDO

EVDOHSPA

4G

MESSAGE

MULTIMEDIA

STREAMING

INTERACTIVITY

Data Rate vs Mobility

4G

WLANHiperlan /2

Fixed WiMAX

MobileWiMAX

LTE

3G

0.1 1 10 100

Fast

Medium

Slow

Movable

Stationary 2000

2010

4G Mobile Technology

GSM

GPRSEDGE

UMTS WCDM

A

HSDPAHSUPA

EVDO EVDVIS-95

CDMA1x WiMAX

4G Objectives

4G Approaches

All-IP Network

API

Services

Mobility Mgmt

Resource Mgmt

QoS Mgmt

Application

Network

Convergence Sublayer

2G 3G WiMAX 4G

Physical

Layered NGMN Architecture

SIP Applications Server Parlay / OSA ….

Application

Service

SessionControl

Access

Multiparty Conferencin

gResource Sharing

Virtual Collaboration Broadcasting Games ….

I-CSCF P-CSCFHSS S-CSCF MGCF

MGW

PSTNWiFi/WiMAXGPRSUMTS

Diameter SIP

SIP H.248

RNC

P-CSCF

I-CSCF

S-CSCF

GGSN

SGSN

IMS

AS

HSS

UTRAN

IMSLain

IMSLain IMS, Internet Multimedia Subsystem

CSCF, Call Session Control Function (Serving, Proxy, Interrogating)GGSN, Gateway GPRS Support NodeSGSN, Serving GPRS Support NodeUTRAN, UMTS Terrestrial Radio Access NetworkUMTS, Universal Mobile Telecom SystemHSS, Home Subscriber Server

IMS

RNC

P-CSCF

I-CSCF

S-CSCF

SFMSFA

GGSN

SGSN

IP ROUTERWiMAX ASN

WiMAX CSNIMS

IMSLain

ASNLain

AAAPDG

HSS

UTRAN

BGCF

S-CSCF

AS

MGCF

MGW

MRFC

MRFPHSS

SLF

I-CSCF

P-CSCFUE

BGCF

S-CSCF

AS

MGCF

MGW

MRFC

MRFP

Data base

I-CSCF

P-CSCFMS

AAA

PDF

Position ServerPDE

3GPP

3GPP2

IMS: EnhancedCharging FunctionSubscriber Profile

Function

Signalling Function

QoS Policy & Media Function

Media Transfer Function

HTTP signal proxy

RTSP signal proxy

CFCS

Application Policy Function

SIP

HTTPRTSP

SIPHTTPRTSP

RTPHTTP

Voice

Video Phone

Video Streamin

g

TV

Web

IPv6 Support

Cognitive Radio

DSA & CR

IEEE 1900 is a suite to support cognitive radio (CR), dynamic spectrum access (DSA), and coexistence.

Previous standards s.a. WiFi (802.11), Zigbee (802.15.4), and WiMAX (802.16) have included certain level of CR.

CR will be related to dynamic spectrum access (DSA), which is the real-time adjustment of Spectrum Utilization in response to changing circumstances and objectives.

The most interesting aspect is coexistence: resource selection to determine the type of wireless/mobile access.

IEEE 1900

SCC41 Working Groups

3G 4G WiMAX WiMAX II(806.16m)

WiFi(802.11g)

WiFi NG(802.11m)

DSA-enabledRadios

Network Management

Legacyterminal

P190

0.4

Term

inal

P190

0.4

Term

inal

IEEEP1900.4

Network reconfigurati

on managemen

t

Terminal reconfigurati

on managemen

t

Terminal reconfigurati

on managemen

t

Metropolitan Short-RangeCellular

Multiplatform Portability

Access Scheme

New access schemes like Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Interleaved FDMA and Multi-carrier CDMA (MC-CDMA) are gaining more importance for the next generation systems.◦ WiMAX: OFDMA◦ LTE: OFDMA (downlink), IFDMA (uplink)

The other important advantage of the above is that they require less complexity for equalization at the receiver. This is an added advantage especially in the MIMO environments since the spatial multiplexing transmission of MIMO systems inherently requires high complexity equalization at the receiver.

In addition to improvements in these multiplexing systems, improved modulation techniques are being used. Whereas earlier standards largely used PSK, more efficient systems such as 64QAM are being proposed for use with the LTE

Access Scheme

Orthogonal frequency-division multiplexing◦ FDM in which sub-channels overlap without

interfering

OFDM

Single Carrier Transmission(WCDMA etc)

Orthogonal FrequencyDivision Multiplexing

5 MHz

e.g. 5 MHz

Subcarriers

Adaptable to severe channel conditions without complex equalization.

Robust against narrow-band co-channel interference.

Robust against intersymbol interference (ISI) and fading caused by multipath propagation.

High spectral efficiency. Efficient implementation using FFT Low sensitivity to time synchronization errors. Facilitates Single Frequency Networks (SFNs), i.e.

transmitter macrodiversity.

OFDM Advantages

TDMA/FDMA operation = OFDMA Frequency sub-channels are composed of

multiple, non-adjacent carriers

OFDMA: Combining TDMA and FDMA

TX#4TX#3

TX#2

TX#6

TX#5

TX#1

Time

Freq

uenc

y bi

n

2468

1012141618202224262830

00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Multipath – The Challenge

OFDM modulates in parallel multiple narrow band sub-carriers

Multipath duration becomes short relative to symbol duration

Pilot and guard sub-carriers are also inserted

Multipath – The Solution

Data carriers

Total Frequency band

Pilot Carriers

Frequency guard Band Frequency Guard Band

The sub-carriers are converted by IFFT to a time domain signal

A guard interval (cyclic prefix) is added to collect multipath

A long guard interval (GI) reduces efficiency but enhances multipath handling capability

Multipath – The Solution

GI

t

OFDM symbol

Narrowband Interference Rejection◦ Easy to Avoid/Reject Narrowband Dominant

Interference .◦ Less Interfered Part of the Carrier Can Still Be

Used .

Interference Rejection/Avoidance

InterferenceUser SubCarriersAllocation

SubCarriers

Interference

SubCarriers

NulledSubCarriers

Total Frequency band

Using shaping on the signal peaks Limiting the PAPR to a constant value by

vector reduction

PAPR Reduction

Rectangular Spectrum Shape (Brick Wall) Small Frequency Guard band

Spectrum Properties

OFDM

Single CarrierScheme

4 MHz

-80

Frequency(MHz)

dB

Spectrum Properties

In OFDM, channel impairment are solved in the same way Group Delays are solved, by Channel estimation

Group Delay

Phase Noise Effects

Phase Noise Effect on OFDM

Phase Noise Effect on S.C

Duplexing

t

t

f

f

duplexseparation

guard period

FDD

TDD

FDD (Frequency Division Duplexing) uses one frequency for the downlink, and a second frequency for the uplink.

TDD (Time Division Duplexing) uses the same frequency for the downlink and the uplink.

In both configuration the access method is OFDMA/TDMA .

Duplexing (cont’d)

F2 - Frequency band

UpLink

F1 - Frequency band

DownLink

FDD

F1 - Frequency band

UpLink

F1 - Frequency band

DownLink

TDD

Spatial Multiplexing

MIMO System

y=Hx+n

Tx Rx

MIMI Schemes

MIMO Techniques Comparison

MIMO Capabilities

Adaptive MIMO

Space Time CodingA space–time code (STC) is a method employed to improve the reliability of

data transmission in wireless communication systems using

multiple transmit antennas. STCs rely on transmitting multiple, redundant

copies of a data stream to the receiver in the hope that at least some of them may survive the

physical path between transmission and reception in a good enough state

to allow reliable decoding.

Space Time Coding

Subcarrier

Modulation

IFFT Input

Packing

Tx Diversity Encoder

IFFT Filter DAC RF

IFFT Filter DAC RF

RF ADC Filter FFTDiversity Combine

r

Sub channel Demod

Decoder

Schedules & Candidates

ITU 4G Schedule

LTE & WiMAX II Terminologies

Context-AwareMobile Applications

Available network

Location (micro)User

activity

Favourite places

Battery power

Speed & direction

QoC

Features on

device

Geo location

User-ContextService

Admin

Networks

PersonalisedServices

User:•Interest•Device•Time•Location

2G 3G LTE WiMAX

ServiceDiscovery

ServiceCompositio

nPervasiven

essContext

Management

User layer(anywhere, anytime)

User experience management

Network access

e-Services

Pers

onal

Serv

ice

Plat

form

Conv

enti

onal

Serv

ice

Plat

form

Thank You

Kuncoro Wastuwibowo