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An Introduction of 3GPP Long Term Evolution (LTE) SpeakerTsung-Yin Lee

An Introduction of 3GPP Long Term Evolution

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  • An Introduction of3GPP Long Term Evolution (LTE)

    SpeakerTsung-Yin Lee

  • 2Reference http://www.tcs.com LTE-Advanced: Future of Mobile Broadband,

    TATA Consultancy Services Takehiro Nakamura ,Proposal for Candidate Radio Interface Technolo

    gies for IMTAdvanced Bas d on LTE Release 10 and Beyond, 3GPP TSGRAN Chairman

    3GPP LTE Channels and MAC Layer, EventHelix.com Inc. 2009 Ahmed Hamza, Network Systems Laboratory Simon Fraser University,

    Long Term Evolution (LTE) - A Tutorial, October 13, 2009 Jim Zyren, Overview of the 3GPP Long Term Evolution Physical

    Layer, Document Number: 3GPP EVOLUTIONWP Rev0 07/2007 David Astly, Erik Dahlman, Anders Furuskr, Ylva Jading, Magnus

    Lindstrm, and Stefan Parkvall, Ericsson Research, LTE: The Evolution of Mobile Broadband , IEEE Communications Magazine, April 2009

  • 3Outline History of 3GPP LTE Basic Concepts of LTE Introduction of LTE Protocol Compare with LTE and LTE-Advanced Conclusion

  • 4What is LTE ?

    In Nov. 2004, 3GPP began a project to define the long-term evolution (LTE) of Universal Mobile Telecommunications System (UMTS) cellular technology Higher performance Backwards compatible Wide application

  • 5Evolution of Radio Access Technologies

    LTE (3.9G) : 3GPP release 8~9

    LTE-Advanced :3GPP release 10+

    802.16d/e

    802.16m

  • 6LTE Basic Concepts LTE employs Orthogonal Frequency

    Division Multiple Access (OFDMA) for downlink data transmission and Single Carrier FDMA (SC-FDMA) for uplink transmission

  • 7Multipath-Induced Time Delays Result in Inter-Symbol Interference (ISI)

    )()()()( tnmtStSty ++= y(t) : output signalS(t) : input signalS(t-m) : delayed m time input signaln(t) : noise

    y(t)

    S(t-m)S(t)

  • 8Equalizers in Receiver Against Frequency Selective Fading

    Channel transform function Hc(f)

    Equalizers transform function Heq(f) (Receiver)

    fmjc efH pi 21)( +=

    fmjc

    cefHfH pi 211

    )(1)(

    +==

    )()()( mtStSty +=

  • 9Frequency Selective Fading the coherence bandwidth of the channel is

    smaller than the bandwidth of the signal

    It may be useless for increasing transmission power

    Frequency Correlation > 0.9Bc = 1 / 50 is r.m.s. delay spread

  • 10

    Cyclic Prefixes

  • 11

    FDM vs. OFDM

  • 12

    LTE-Downlink (OFDM) Improved spectral

    efficiency Reduce ISI effect

    by multipath Against frequency

    selective fading

  • 13

    LTE Uplink (SC-FDMA) SC-FDMA is a new single carrier multiple access

    technique which has similar structure and performance to OFDMA

    A salient advantage of SC-FDMA over OFDM is low to Peak to Average Power Ratio (PAPR) :

    Increasing battery life

  • 14

    Multi-antenna techniques

  • 15

    Generic Frame Structure Allocation of physical resource blocks

    (PRBs) is handled by a scheduling function at the 3GPP base station (eNodeB)

    Frame 0 and frame 5 (always downlink)

  • 16

    Resource Grid

    One frame is 10ms 10 subframes

    One subframe is 1ms 2 slots

    One slot is 0.5ms N resource blocks[ 6 < N < 110]

    One resource block is 0.5ms and contains 12 subcarriers from each OFDM symbol

  • 17

    LTE spectrum (bandwidth and duplex) flexibility

  • 18

    LTE Downlink Channels

    Paging Channel

    Paging Control Channel

    Physical Downlink Shared Channel

  • 19

    LTE Uplink Channels

    Random Access Channel

    Physical Radio Access Channel

    Physical Uplink Shared ChannelCQI report

  • 20

    LTE Release 8 Key Features (1/2) High spectral efficiency

    OFDM in Downlink SingleCarrier FDMA in Uplink

    Very low latency Short setup time & Short transfer delay Short hand over latency and interruption time

    Support of variable bandwidth 1.4, 3, 5, 10, 15 and 20 MHz

  • 21

    LTE Release 8 Key Features (2/2) Compatibility and interworking with earlier

    3GPP Releases FDD and TDD within a single radio access

    technology Efficient Multicast/Broadcast

  • 22

    Evolution of LTE-Advanced Asymmetric transmission bandwidth Layered OFDMA Advanced Multi-cell

    Transmission/Reception Techniques Enhanced Multi-antenna Transmission

    Techniques Support of Larger Bandwidth in LTE-

    Advanced

  • 23

    Asymmetric transmission bandwidth Symmetric transmission

    voice transmission : UE to UE Asymmetric transmission

    streaming video : the server to the UE (the downlink)

  • 24

    Layered OFDMA The bandwidth of basic frequency block is,

    1520 MHz Layered OFDMA radio access scheme in

    LTE-A will have layered transmission bandwidth, support of layered environments and control signal formats

  • 25

    Advanced Multi-cell Transmission/Reception Techniques

    In LTE-A, the advanced multi-cell transmission/reception processes helps in increasing frequency efficiency and cell edge user throughput Estimation unit Calculation unit Determination unit Feedback unit

  • 26

    Enhanced Multi-antenna Transmission Techniques In LTE-A, the MIMO scheme has to be further improved

    in the area of spectrum efficiency, average cell through put and cell edge performances

    In LTE-A the antenna configurations of 8x8 in DL and 4x4 in UL are planned

  • 27

    Enhanced Techniques to Extend Coverage Area Remote Radio Requirements (RREs) using optical

    fiber should be used in LTE-A as effective technique to extend cell coverage

  • 28

    Support of Larger Bandwidth in LTE-Advanced Peak data rates up to 1Gbps are expected

    from bandwidths of 100MHz. OFDM adds additional sub-carrier to increase bandwidth

  • 29

    LTE vs. LTE-Advanced

  • 30

    Conclusion LTE-A helps in integrating the existing

    networks, new networks, services and terminals to suit the escalating user demands

    LTE-Advanced will be standardized in the 3GPP specification Release 10 (LTE-A) and will be designed to meet the 4G requirements as defined by ITU

  • 31

    Backup

  • 32

    LTE Downlink Logical Channels

  • 33

    LTE Downlink Logical Channels

  • 34

    LTE Downlink Transport Channel

  • 35

    LTE Downlink Transport Channel

  • 36

    LTE Downlink Physical Channels

  • 37

    LTE Downlink Physical Channels

  • 38

    LTE Uplink Logical Channels

  • 39

    LTE Uplink Transport Channel

  • 40

    LTE Uplink Physical Channels