Wireless Communication Systems II

7/29/2019 Wireless Communication Systems II

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Mobile Communication

Systems-II

Dept. of Elec. Eng. IUST, Tehran/Iran

email add. [email protected]

Chapter One

Introduction
mailto:[email protected]:[email protected]


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Marks:

Midterm Exam: 20%

Final Exam: 50%

Assessments and Project: 30%


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Contents

Chapter 1: Introduction

The Evolution of Mobile Radio Systems

Basic Knowledge of Mobile Radio Channels

Structure of the Lecture Note

Chapter 2: Important Probability Density Functions

Stochastic Processes

Deterministic, Continuous and Discrete Time Signals

Rice and Rayleigh Processes

Methods for the Computation of Doppler Freqs. & Coefs:

Equal Distances (ED), Mean Square Error (MSE)Equal Area (EA), Monte-Carlo (MC), Lp-Norm (LPN), Exact

Doppler Spread (EDS), Jakes


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Contents

Chapter 3: Frequency Non-Selective Channel Models

Suzuki Process

Modeling and Analysis of Short-Term Fading

Modeling and Analysis of Long-Term FadingRice and Rayleigh Process

Jake's and Loo Model

Chapter 4: Frequency Selective Channel Models

Ellipses Model of Parsons and Bajwa

WSS, US and WSSUS Models

Cost207 and Cost259 Models and Simulations

Fast Channel Simulators


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Contents

Chapter 5: Hardware and Software Chammel Simulators

Hardware and Software Simulator Designs

DSP/OMAP/FPGA Hardware Channel Simulators

Simlator Applications

Chapter 6: System Analysis Fundamentals

Narrow-Band & Wide-band Digital Channel Systems

The UTRA FDD Mode WCDMA

The UTRA TDD Mode WCDMA

CDMA System PerformancePower Control and Soft Handover Characteristics


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Contents

Chapter 7: UMTS Development Platform

UMTS High Level Architectures

The UMTS Domains

Circuit Switched and Packet Switched Network Element

3G Serving GPRS Support Systems

Chapter 8: IMT-2000 Development Platform

The IMT-2000 Family


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Contents

Chapter 9: The UTRA Physical Layer Design

Random Accessing

Burst-by-Burst Adaptive Wireless Transceivers

Synchronization and Pilot Channels

Spreading and Adaptive Modulation

Multi-User Detection

Blind Adaptation

Multiplexing and Channel Coding

Intelligent Antenna Arrays and Beam-forming

Uplink and Downlink Power Control Channels

Mapping Transport Channels onto Physical Channels


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Contents

Chapter 10: The UTRA Transmission SystemsUMTS Spectrum Allocations

Base Stations and Maximum Output Power

Spurious Emission

Receiver Characteristics:Diversity

Adjacent Channel Selectivity

Blocking and Inter-Modulation

Propagation Models

Macro, Micro and Pico Cells


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Contents

Chapter 11: Developing. 3G NetworkSoft Handover and Orthogonal Processing

Multi-service Traffic with circuit and packet switched services

Link Budgets

Core Network Elements and Design

GSM, GSM1800 and UMTS Interference

Chapter 12: IP Based NetworkThe UMTS Release 99 and 00 Medium Term Architectures

Release R4 and R5

Multimedia Resource FunctionsMultimedia Signaling


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A Dramatic, Novel, Short and Rich Inventional andIndustrial HistoryRrelatively brief (half a century-analog) with the US as aIndustrial Pioneer(mostly analog),

The first citizen automobile radiotelephone (car phone)serviced in the US in 1946 (Detroit Police).

But it was in Japan that the practical mobile system in VHFband became fully operative in 1948 and immediatelyDetroit as Japanese claim and in Iran, full duplex mobile

system with transceiver in 1952 by ITRC .From 1948 to 1980 systems such as Paging, publiccordless (80s) were kept coming into the governmentalmarket services (police, ambulances, etc.) but only in North

America, Japan and Britain.

Wireless CommunicationHistory


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Wireless CommunicationHistory

Developments in land mobile communicationsprogressed slowly following these initialintroductions, but with the advent of theinformation age in the late 1980s, new servicesstarted being offered, resulting in a phenomenalincrease in the demand and proliferation of publiccommunication systems, which continues to thepresent. Specifically, the portable telephone wasintroduced as radiotelephone in 1989, and the

service started in 1993 for digital portable andmobile radiotelephone systems. This is followed in1995 with the introduction of the Personal Handy-Phone System (PHS).


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Historically, land mobile communication systems have used frequencies inrelatively low bands, but with the increase in the number of wireless

stations (terminals), frequency assignments have expanded from VHF

into the UHF region. First frequency allocation given to governmental

(public services) as bellow:

60 MHz band Public agency use

150 MHz band Public agency use, radio systems for general

business amateur radio

250 MHz band Pager, cordless telephone

400 MHz band Public agency use, radio systems for general

business, low power radio and amateur radio, etc.

800 MHz band Land mobile radiotelephones, digital land mobile

radiotelephones and terminals

1.5GHz band Digital portable land mobile radiotelephones, etc.

1.9-3GHz PHS, radio LAN, UMTS and IMT-2000

3.6-12Gz UWB, RFID, WSN, Bluetooth, etc.

Wireless CommunicationFrequency Bands


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Mobile Systems TechnicalHistory

The Evolution of Digital Mobile Radio Systems (1994)

A brief evolution description of many years

system architectures and supporting technologies

is presented starting from the birth of GSM

(Global System for Mobile coms.) 2nd generation

digital mobile communication system.

GSM- The most widespread (mostly digital) mobile

system in the world today providing the basis to

cover the introduction of UMTS (Universal MobileTelecommunication Services) in relation to its

Core Network (CN) and radio architectures.


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l The original scope of 3GPP was to produce Technical

Specifications and Technical Reports for a 3G Mobile

System based on evolved GSM core networks and the

radio access technologies that they support (i.e.,

Universal Terrestrial Radio Access (UTRA) bothFrequency Division Duplex (FDD) and Time Division

Duplex (TDD) modes).

l The scope was subsequently amended to include the

maintenance and development of the Global System for

Mobile communication (GSM) Technical Specificationsand Technical Reports including evolved radio access

technologies (e.g. General Packet Radio Service (GPRS)

and Enhanced Data rates for GSM Evolution (EDGE)).



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The Growth of Mobile Communications

A simultaneous growth with Internet revolution not onlyincorporated industrial environments but also, grew withindomestic applications.

Q1. What is the Internet has to do with Mobile system and/orUMTS?

A summary of digital data transmission

over wireless channels:1- 14.4Kb/s allows GSM data calls with a rate of 14.4Kb/s per time

slot, resulting in a 50% higher data throughput compared to thecurrent maximum speed of 9.6Kb/s.

2- High Speed Circuit Switched Data (HSCSD) aggregatessymmetrically or asymmetrically several circuit channels, e.g.28.8Kb/s for two time slots (2+2) or 43.2Kb/s for three time slots(3+1).

3- General Packet Radio Service (GPRS) enables GSM withInternet access at high spectrum efficiency by sharing time slotsbetween different users. It affords data rates ofover 100Kb/s to asingle user while offering direct IP connectivity.

Mobile Systems Technical History


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A summary of digital data transmissionover wireless channels:

4- Enhanced Data Rate for GSM Evolution (EDGE)modifies the radio link modulation scheme from

GMSK to 8QPSK. Thereby increasing by three times theGSM throughput using the same bandwidth. EDGE incombination with GPRS (E-GPRS) will deliver single userdata rates of over300Kb/s.

5- UMTS as 3rd generation wireless technology utilizes aWideband CDMA or TD/CDMA transceiver. Starting with

channel bandwidths of 5MHz it will offerdata rates up to2Mb/s. UMTS uses different spectrum and new radionetwork configurations while using the GSM coreinfrastructure.



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Although the circuit switched enhancements such asHSCSD increases transmission rates, it is packet

switched enhancements, which will meet the challenges

or demands posed on current wireless networks. The

GPRS and UMTS with EDGE as an intermediate solution

will provide the platform to support integrated services ofvoice and data including multimedia.

While GPRS, IMT and UMTS meet the demands for Internet

(IP) features and higher bandwidth in mobile networks,

another evolution step is taking place in the network

infrastructure. This is the convergence ofsingle networksinto a multi-purpose backbone network. An impact on the

implementation of UMTS specially IMT radio access

technologies.

Advanced WirelessCommunication System History


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Basic Confugration of the RadioTransmision System

Noise

Multiplexer

Modulator

Medium

Bit

Stream

Digital

Waveform

Bit and CarrierSynchronization

Source

Encoder

Encrpytion

Information

Source

Format

Channel

EncoderLine

Encoder

TX

Frequency

Spread

Multiple Access

RX

Multiple Access

Frequency

Despread

De-Mod

De-Mux

Line

DecoderChannel

Decoder

Decryption

SourceDecoder

Format

InformationSink

Fading

Countermeasure I

Fading

Countermeasure II


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GSM Signalling and

Data Transport

SS#7 and leased

line

HLR

AUC

AUC

HLRBSC

BTSBTS

EIR

VLR

MSC

VLRMSC

VLR

GMSC

Signalling

Data

Signalling

Data and

user Data

PSTN

ISDN

PDN


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A channel in the uplinkand the downlink are

combined to form a

duplex pair.

The two channels are

separated by 45MHz.Typically a MN will

produce 0.6W of

power.

The uplink frame

happens after the

downlink frame.

Carrier Frequencies and

TDMA Frames (GSM900)

Q2;- Draw the two

FDMA channel andTDMA time slots for

GSM1800. Guass what

are Freq. Sep. and MN.


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l Each 200 kHz FDMA channel has 8 TDMA time slot

channels.

l Uplink slots are transmitted with a delay of three time

slots referred to the downlink.

l Handset uses the same duplex number in the uplinkas in the downlink say Channel 93 time slot 3.

Slot Transmission and

Duplexing

l Each TDMA slot lasts 15/26 ms = 576.9

s. If used, a slot can contain a data burst

which lasts 156.25 bit.

l Since in the handset Tx and Rxoperations are at different times the

handset needs no duplexer and can

therefore be made more cheaply.


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UMTS Services Aspects:

UMTS is the realization of a new generation ofmobile communication technology for a world inwhich personal communications services shouldallow person-to-person calling, independent oflocation, the terminal used, the means of

transmission (wired or wireless) and the choiceof technology.

Important services can be namely:

Service Management

Charging and Billing

Network management

Quality Of Service (QoS)

Security


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Mobile Systems Technical History


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UMTS, IMTObjectives and Goals

To provide a single integrated system:Users can be able to access services in an easy touse and uniform way in all environments.

To allow differentiation:

Between service offerings of various servingnetworks and home environments.

To provide a wide range of telecommunicationservices:

Fixed networks and requiring user bit rates of up to2Mb/s plus mobile services (residential, public andoffice environments i.e in diverse dense populatedareas) compatible to fixed service quality.


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UMTS, IMTObjectives and Goals

To provide services at will:Via hand held, portable, movable and fixed terminalsin all radio environments.

To provide support of roaming users:

Enabling users to access services provided by theirhome environment in the same way even whenroaming.

To provide:

Audio, data, video and particularly multi-media.

To provide:

The flexible introduction of telecommunication

services of future.


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UMTS Objectives and Goals

To provide:

Pedestrian user to access all services normally

offered by fixed networks.

To provide:

A substitute for fixed networks in diverse densely

populated areas approved by the areas authority.

To provide support for interfaces:

Allowing the use of terminals normally connected to

fixed networks.

Q5- Can you think of any further objectives UMTS

can provide? See ETSI Specifications


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UTRA: UMTS Terrestrial Radio AccessHigh level requirements

Maximum user bit rates1. Rural Outdoor: at least 144kb/s (aim=> 384kb/s)at max. speed of 50km/h.

2. Suburban Outdoor: at least 384kb/s (aim=>512kb/s) at max. speed of 120km/h.

3. Indoor/ Low range Outdoor: at least 2Mb/s atmax. speed of 10km/h.

4. The UTRA definition should allow evolution

towards higher bit rates

Bearer Capabilities:-


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Bearer Capabilities:- Flexibility1. Negotiation of bearer service attributes (bearer type, BER, bit

rate, delay, etc)

2. Parallel bearer services (service mix), real/non real-timecommunication modes, etc.

3. Circuit and packet bearer oriented bearer.4. Support scheduling (and pre-emption) of bearers (including

control bearers) within priority.

5. Adaptability of link to quality, traffic and network load, as wellas radio conditions.

6. Wide range of bit rates should be supported with sufficientgranularity.

7. Variable bit rate real time capabilities should be provided.

8. Bearer services appropriate for speech shall be provided.


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Handover:1. Provide seamless (to user) handover between cells of

one operator.

2. The UTRA should not prevent seamless HO betweendifferent operator or access networks

3. Efficient handover between UMTS and 2nd generationsystem, e.g. GSM, should be possible.

l Operational Requirements:-Compatibility with services provided by present core

transport networks:

1. ATM bearer services2. GSM services

3. IP - based services

4. B/N-ISDN services


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Radio access network planning:If radio resource planning is required, automatic planningshall be supported.

Public network operators:It shall be possible to guarantee pre-determined levels of

QoS and quality to public UMTS ops.Private and residential operators:

1. The radio access scheme should be suitable for lowcost applications where range, mobility and user speedmay be limited.

2. Multiple unsynchronized systems should be able tosuccessfully co-exist in the same environment.3. It should be possible to install base stations without co-ordination.

4. Frequency planning should be needed.


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l

Efficient spectrum usage:-Spectrum efficiency:1. High spectrum efficiency for typical mixtures ofdifferent bearer services.

2. Spectrum efficiency at least as good as GSM for low bitrate speech.

Variable asymmetry of total band usage:Variable division of radio resource between up-link anddown-link resources from a common pool (NB: thisdivision could be in either frequency, time, or codedomains).

Spectrum Utilization:

1. Allow multiple operators to use the band allocated to UMTSwithout co-ordination.

2. It should be possible to operate the UTRA in any suitablefrequency bands.


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l Efficient spectrum usage:-Coverage/Capacity:

1. The system should be flexible to support a variety of initialcoverage/capacity configurations and facilitate coverage/capacity evolution.

2. Flexible use of various cell types and relations between cells (e.g. indoorcells, hierarchical cells) within a geographical area without under waste ofradio resources.

3. Ability to support cost effective coverage in rural areas.

Mobile terminal viability:1. Hand-portable and PCM-CIA card sized UMTS terminals should be viable interms of size, weight, operating time, range, effective radiated power and cost.

Network complexity and cost:The development and equipment cost should be kept at a reasonable level,

taking into account cell site cost, cross-connect, signaling load and trafficoverhead (e.g. due to handovers).

Mobile station types:1. It should be possible to provide a variety of mobile station types of varyingcomplexity, cost and capabilities in order to satisfy the needs of differenttypes of users


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Requirements from bodies outside GSM:-Alignment with IMT-2000:

UTRA shall meet at least the technical requirements submission as a candidatetechnology for IMT-200.

Minimum bandwidth allocation:

It should be possible to deploy and operate a network in a limited bandwidth (e.g.5MHz).

Electro-magnetic compatibility (EMC):

The peak and average power and envelope variation have to be such that the degreeof interference caused to other equipment is not higher than in todays system.

RF radiation effects:

UMTS shall be operative at RF emission power levels, which are in line with therecommendations related to electromagnetic radiation.

Security:

The UMTS radio interface should be able to accommodate at least the same level ofprotection as the GSM radio interface does.

Co-existence with other systems:1. The UMTS Terrestrial Radio Access should be capable of coexisting with othersystems within the same or neighbouring band depending on systems andregulations

2. Multi-mode implementation capabilities.

3. It should be possible to implement dual mode UMTS/GSM terminals cost effectivel


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By looking at the bearer capabilities fromprevious three slides one can conclude:

Evolution towards higher rates will initially apply mainly to

indoor rates. In this environment convergence will also have

higher impact. In addition, UTRA will not only prevent

seamless HO between different operators or access

networks, but also support HO between 2G and 3G system,

e.g. GSM and UMTS.

UTRA will support key technologies, like ATM, IP, BISDN,

as well as GSM, when it comes down to core network (CN)

transport. This will constitute the trend of 2G CN towards

integrated circuit switched and packet switched services.

UTRA: UMTS Terrestrial Radio AccessConcluding Remarks


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Enhancing Technologies:By increasing the number of BS antennas we can

resolve the uplink limitation of WCDMA.

This approach does not allow a single step solution

because many factors intervene before completingprocess.

UTRA will support key technologies, like ATM, IP,

BISDN, as well as GSM, when it comes down to

core network (CN) transport. This will constitute thetrend of 2G CN towards integrated circuit switched

and packet switched services.

UMTS Fields:-Capacity Increasing Antennas


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Student Activity

Q2- Describe the system configurations of two types of landmobile communication systems, and discuss the basictechniques used by each system.

Q3- Describe the relationship between the multiple accesssystem and the radio communication system (the combinedtechniques of radio signal transmission and radio link control)used in land mobile communication system.

Q4- Describe what is considered as the major problemcharacteristics of land mobile communications, and give anexample of the countermeasures used to solve the problem.


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References:

[1]. M. Patzold, "Mobile Fading Channels", John Wiley & Sons, 2002

[2]. H. Sasaoka, "Mobile Communications", IOS Press, Wave Summit Course, 2000.

[3]. H. Holma and A. Toskala, "WCDMA for UMTS", John Wiley & Sons, 2001.

[4]. J.P. Castro, "The UMTS Network and Radio Access Technology", John Wiley & Sons,

2001.

[5]. J.S. Blogh and L. Hanzo, "Third Generation and Inteligent Wireless Networking",

John Wiley & Sons, 2002.

[6]. K. Tachikawa, "W-CDMA Mobile Communications Systems", John Wiley & Sons,2002.

[7] J. G. Proakis, "Digital Communication" 2nd edn, McGraw-Hill, New York, 2000

[8]. W. C. Y. Lee, "Mobile Communication Engineering: Theory and Applications",

McGraw-Hill 1998.

[9]. T.J. Willink, "MIMO OFDM For Broadband Fixed Access", IEE Proc. On Comm., Feb

2005.

[10]. C.R.N. Athaudge and A.D.S. Jayalath, "Delayed Spread estimation using cyclic-Prefix in Wireless OFDM Systems", IEE Proc. On Comm., Dec 2004.

[11]. R.D. Latima and D. R. Yarwood, "UMTS 2004", ETSI Book Publications 2004.

[12]. M.C. Roma and D. Ryanold, "WCDMA and IMT-2000", IEEE Book Publications, Nov.

2004.

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