2006 Ee 425 2006 Ee 455 2006 Ee 461

2006-EE-425 2006-EE-455 2006-EE-461 1

4G Technology What is 4G technology: 

4G is short for Fourth Generation wireless Technology. It is basically the extension in the 3G technology with more bandwidth and services offers in the 3G. But at this time nobody exactly knows the true definition for 4G. Some people say that 4G is the future technologies that are mostly in their maturity period. The expectation for the 4G technology is basically the high quality audio/video streaming over end to end Internet Protocol. If the Internet Protocol (IP) multimedia sub-system movement achieves what it going to do, nothing of this possibly will matter. WiMAX or mobile structural design will become progressively more translucent, and therefore the acceptance of several architectures by a particular network operator ever more common.

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4G Technology Contd.. 

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Many Technologies appear in many different flavors and have many diverse tags attached to them, but that does not really indicate that they are moving in dissimilar tracks. The technologies that fall in the 4G categories are UMTS, OFDM, SDR, TD-SCDMA, MIMO and WiMAX to the some extent. Some of the companies trying 4G communication at 100 Mbps for mobile users and up to 1 Gbps over fixed stations. They planned on publicly launching their first commercial wireless network around 2010

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Microcellular Wireless Data Evolution & AT&T’s Roadmap Wideband OFDM

5M

1M HDR data 384 k rate

GPRS 64 k 9.6 k

EDGE WCDMA

IS-136+ IS-95+ PDC GSM IS-136 CDPD IS-95 1995

2000

2005 4

Generations Timeline

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Public cells before 4G

Small public cells after 4G due to high carrier frequency and high data rate.

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MIMO 

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Multiple-input and multiple-output, or MIMO (commonly pronounced my-moh or me-moh), is the use of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology. MIMO technology has attracted attention in wireless communications, since it offers significant increases in data throughput and link range without additional bandwidth or transmit power. It achieves this by higher spectral efficiency (more bits per second per hertz of bandwidth) and link reliability or diversity (reduced fading). Because of these properties, MIMO is a current theme of international wireless research.

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MIMO Contd..

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MIMO Contd.. 

MIMO can be sub-divided into three main categories, precoding, spatial multiplexing or SM, and diversity coding

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Spatial multiplexing requires MIMO antenna configuration.

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In spatial multiplexing, a high rate signal is split into multiple lower rate streams and each stream is transmitted from a different transmit antenna in the same frequency channel. If these signals arrive at the receiver antenna array with sufficiently different spatial signatures, the receiver can separate these streams, creating parallel channels free. Diversity Coding techniques are used when there is no channel knowledge at the transmitter. In diversity methods a single stream (unlike multiple streams in spatial multiplexing) is transmitted, but the signal is coded using techniques called space-time coding. 9

Summary of 3G MIMO Generation  

3G  

3G evolution  

Beyond 3G  

Future  

Deployment

2003/4

2005~6/2007~8/2009~10

2012~2015

2015~2020

Standard

WCDMA

HSPA/HSPA+/LTE

IMT-Advanced

Beyond IMT-Adv

Total rate

384kbit/s

14/42/65~250Mbit/s

1Gbit/s

>10Gbit/s

Bandwidth

5MHz

5MHz/20MHz

20~100MHz

>100MHz

Requirement Paradigm

Method

Spatial coding (SC)

High reliability (High quality)

High rate (High capacity)

Lower interference

High intelligence

Spatial diversity

Spatial multiplexing

Spatial cancellation

Ambient intelligence

Spatial diversity coding

Spatial multiplexing coding

Spatial cancellation coding

Ambient intelligence coding

Multi-stream beamforming

Interference nulling beamforming

Ambient intelligence beamforming

SC: Alamouti coding, SB: TxAA SC: BLAST coding, SB: SVD

SC: DPC, SB: MU-BF

Such as cooperative MIMO

Spatial beamforming (SB) Single-stream beamforming

Examples

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LTE 

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LTE (Long Term Evolution) is the last step toward the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile telephone networks The LTE specification provides downlink peak rates of at least 100 Mbps, an uplink of at least 50 Mbit/s and RAN round-trip times of less than 10 ms. LTE supports scalable carrier bandwidths, from 20 MHz down to 1.4 MHz and supports both Frequency Division Duplexing and Time Division Duplexing. The main advantages with LTE are high throughput, low latency, plug and play, [FDD] and [TDD] in the same platform, with older network technology such as GSM, cdmaOne, W-CDMA (UMTS) improved end-user experience and simple architecture resulting in low operating costs. LTE will also support seamless passing to cell towers , and CDMA2000

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LTE Contd..   

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Peak download rates of 326.4 Mbit/s for 4x4 antennas, 172.8 Mbit/s for 2x2 antennas for every 20 MHz of spectrum.[6] Peak upload rates of 86.4 Mbit/s for every 20 MHz of spectrum.[6] 5 different terminal classes have been defined from a voice centric class up to a high end terminal that supports the peak data rates. All terminals will be able to process 20 MHz bandwidth. At least 200 active users in every 5 MHz cell. (specifically, 200 active data clients) Sub-5ms latency for small IP packets Increased spectrum flexibility, with spectrum slices as small as 1.5 MHz (and as large as 20 MHz) supported (W-CDMA requires 5 MHz slices, leading to some problems with roll-outs of the technology in countries where 5 MHz is a commonly allocated amount of spectrum, and is frequently already in use with legacy standards such as 2G GSM and cdmaOne.) Limiting sizes to 5 MHz also limited the amount of bandwidth per handset Optimal cell size of 5 km, 30 km sizes with reasonable performance, and up to 100 km cell sizes supported with acceptable performance

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TD-SCDMA Time Division Synchronous Code Division Multiple Access (TD-SCDMA) or UTRA/UMTS-TDD 1.28 Mcps Low Chip Rate (LCR)[1] [2] , is an air interface[1] found in UMTS mobile telecommunications networks in China as an alternative to W-CDMA. Together with TD-CDMA, it is also known UMTS-TDD or IMT 2000 Time-Division (IMT-TD)[1] .  The term "TD-SCDMA" is misleading. While it suggests covering only a channel access method based on CDMA, it is actually the common name for the whole air interface specification 

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OFDM Orthogonal frequency-division multiplexing 

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Orthogonal frequency-division multiplexing (OFDM) — is a frequency-division multiplexing (FDM) scheme utilized as a digital multi-carrier modulation method. A large number of closely-spaced orthogonal sub-carriers are used to carry data. The data is divided into several parallel data streams or channels, one for each sub-carrier. Each sub-carrier is modulated with a conventional modulation scheme (such as quadrature amplitude modulation or phase shift keying) at a low symbol rate, maintaining total data rates similar to conventional single-carrier modulation schemes in the same bandwidth.

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OFDM Contd..

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SDR A Software-Defined Radio (SDR) system is a radio communication system where components that have typically been implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors. etc.) are instead implemented using software on a personal computer or other embedded computing devices.  While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics are making practical many processes that were once only theoretically possible A basic SDR may consist of a computer (PC) equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general purpose processor, rather than done using special-purpose hardware. Such a design produces a radio that can receive and transmit a different form of radio protocol (sometimes referred to as a waveform) just by running different software. 

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SDR Contd.. 

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Software radios have significant utility for the military and cell phone services, both of which must serve a wide variety of changing radio protocols in real time. The ideal receiver scheme would be to attach an analog-to-digital converter to an antenna. A digital signal processor would read the converter, and then its software would transform the stream of data from the converter to any other form the application requires. An ideal transmitter would be similar. A digital signal processor would generate a stream of numbers. These would be sent to a digital-to-analog converter connected to a radio antenna.

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WiMAX 

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WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunicationstechnology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobile internet access. The Institute of Electrical and Electronics Engineers (IEEE) 802 committee (802.16 ). Orthogonal Frequency Division Multiplexing (OFDM) (carriers of width of 5MHz or greater can be used ) connectivity at speeds up to 70 Mbps provide high speed access to about 60 businesses at T1 speeds. can serve up to a thousand homes in term of DSL speed.

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UMTS 

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Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) mobile telecommunications technologies, which is also being developed into a 4G technology. It is specified by3GPP and is part of the global ITU IMT-2000 standard. The most common form of UMTS uses W-CDMA (IMT Direct Spread) as the underlying air interface but the system also covers TD-CDMA and TD-SCDMA (both IMT CDMA TDD). Being a complete network system, UMTS also covers the radio access network (UMTS Terrestrial Radio Access Network; UTRAN), the core network (Mobile Application Part; MAP) as well as authentication of users via USIM cards ( Subscriber Identity Module).

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UMTS Contd.. 

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UMTS, using W-CDMA, supports maximum theoretical data transfer rates of 21 Mbit/s (with HSDPA), although at the moment users in deployed networks can expect a transfer rate of up to 384 kbit/s for R99 handsets, and 7.2 Mbit/s for HSDPA handsets in the downlink connection. This is still much greater than the 9.6 kbit/s of a single GSM error-corrected circuit switched data channel or multiple 9.6 kbit/s channels in HSCSD (14.4 kbit/s for CDMAOne), and—in competition to other network technologies such as CDMA2000, PHS or WLAN—offers access to the World Wide Web and other data services on mobile devices.

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HSDPA 

High-Speed Downlink Packet Access (HSDPA) is an enhanced 3G (third generation) mobile telephony communications protocol in the High-Speed Packet Access (HSPA) family, also coined 3.5G, 3G+ or turbo 3G, which allows networks based on Universal Mobile Telecommunications System (UMTS) to have higher data transfer speeds and capacity. Current HSDPA deployments support downlink speeds of 1.8, 3.6, 7.2 and 14.0 Mbit/s. Further speed increases are available with HSPA+, which provides speeds of up to 42 Mbit/s downlink and 84 Mbit/s with Release 9 of the 3GPP standards

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Transmission technologies Power fluctuations and frequencies are caused by different access schemes and modulations: • GSM (2G) & EDGE (2,5G) uses GMSK modulations • UMTS (3G) is based on CDMA • 4G uses:  Smart antennas  Multiple-Input-Multiple-Output (MIMO) Systems  Space-Time Coding  Dynamic Packet Assignment  Wideband OFDM

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2G; 2,5G & 3G modulations 2G GMSK modulations Gaussian Minimum Shift Keying

3G QPSK modulations & CDMA Code Division Multiple Access

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4G – OFDM Orthogonal Frequency Division Multiplexing OFDM is being increasingly used in high – speed information transmission systems:  European HDTV  Digital Audio Broadcast (DAB)  Digital Subscriber Loop (DSL) OFDM characteristics • High peak-to-average power levels  IEEE 802.11 Wireless LAN • Preservation of orthogonality in severe multi-path • Support for adaptive modulation by subcarrier • Frequency diversity • Robust against narrow-band interference • Efficient for simulcasting • Variable/dynamic bandwidth • Used for highest speed applications • Supports dynamic packet access 25

Key 3G and 4G Parameters Attribute

3G

Major Characteristic

Predominantly voice- data Converged data and VoIP as add-on Wide area Cell based Hybrid – integration of Wireless Lan (WiFi), Blue Tooth, Wide Area 1.6 - 2.5 GHz 2 – 8 GHz

Network Architecture Frequency Band Component Design

4G

Bandwidth

Optimized antenna; multi- Smart antennas; SW multiband adapters band; wideband radios 5 – 20 MHz 100+ MHz

Data Rate

385 Kbps - 2 Mbps

20 – 100 Mbps

Access

WCDMA/CDMA2000

MC-CDMA or OFDM

Forward Error Correction Switching

Convolution code 1/2, 1/3; Concatenated Coding turbo Circuit/Packet Packet

Mobile top Speed

200 kmph

200 kmph

IP

Multiple versions

All IP (IPv6.0)

Operational

~2003

~2010 26

Key 4G Mobility Concepts 

Mobile IP VoIP Ability to move around with the same IP address IP tunnels Intelligent Internet

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Presence Awareness Technology Knowing who is on line and where

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Radio Router Bringing IP to the base station

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Smart Antennas Unique spatial metric for each transmission 27

4G Networks Advances 

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Seamless mobility (roaming)  Roam freely from one standard to another  Integrate different modes of wireless communications – indoor networks (e.g., wireless LANs and Bluetooth); cellular signals; radio and TV; satellite communications 100 Mb/se full mobility (wide area); 1 Gbit/s low mobility (local area) IP-based communications systems for integrated voice, data, and video  IP RAN Open unified standards Stream Control Transmission Protocol (SCTP)  Successor to “SS7”; replacement for TCP  Maintain several data streams within a single connection Service Location Protocol (SLP)  Automatic resource discovery  Make all networked resources dynamically configurable through IPbased service and directory agents

The demise of SS7 28

Possible applications •Virtual Presence: 4G system gives mobile users a "virtual presence" (for example, always-on connections to keep people on event). •Virtual navigation: a remote database contains the graphical representation of streets, buildings, and physical characteristics of a large metropolis. Blocks of this database are transmitted i rapid sequence to a vehicle •Tele-medicine: 4G will support remote health monitoring of patients. •Tele-geoprocessing: Queries dependent on location information of several users, in addition to temporal aspects have many applications. •Crisis-management applications •Education

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References . www.3gpp.org 2. WCDMA for UMTS, Ed.: H. Holma and A. Toskala, John Wiley, 2001 3. UMTS - Mobile Communications for the Future, Ed. F.Muratore, John Wiley, 2001 4. WCDMA: Towards IP Mobility and Mobile Internet, Eds E.Djanpera and R.Prasad, Artech House, 2001 5. IS-95 CDMA and CDMA2000, V.K.Garg, Publishing House of Electronics Industry, Beijing, 2002 6. IP Telephony, O. Hersent, D. Gurle Et, and J-P Petit, Addison-Wesley, 2000 7. www.mobileinfo.com 1

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Webography • www.comlab.hut.fi/opetus/333/2004_2005_slides/4G_text.pdf • www.cost281.org/download.php?fid=719 • www.telenor.com/telektronikk/Oien_Beyond3G.pdf

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