An Introduction of3GPP Long Term Evolution (LTE).ppt

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1、An Introduction of 3GPP Long Term Evolution (LTE),Speaker：Tsung-Yin Lee,2,Reference,http:/ “LTE-Advanced: Future of Mobile Broadband,” TATA Consultancy Services Takehiro Nakamura ,“Proposal for Candidate Radio Interface Technologies for IMTAdvanced Bas d on LTE Release 10 and Beyond,” 3GPP TSGRAN Ch

2、airman “3GPP LTE Channels and MAC Layer,” EventH 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

3、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 2009,3,Outline,History of 3GPP LTE Basic Concepts of LTE Introduction of LTE Protocol Compare with LTE and L

4、TE-Advanced Conclusion,4,What 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,5,Evolution of Radio Access Technologies,LTE (3.9G) : 3G

5、PP release 89 LTE-Advanced : 3GPP release 10+,802.16d/e,802.16m,6,LTE Basic Concepts,LTE employs Orthogonal Frequency Division Multiple Access (OFDMA) for downlink data transmission and Single Carrier FDMA (SC-FDMA) for uplink transmission,7,Multipath-Induced Time Delays Result in Inter-Symbol Inter

6、ference (ISI),y(t) : output signal S(t) : input signal S(t-m) : delayed m time input signal n(t) : noise,y(t),S(t-m),S(t),8,Equalizers in Receiver,Against Frequency Selective Fading Channel transform function Hc(f)Equalizers transform function Heq(f) (Receiver),9,Frequency Selective Fading,the coher

7、ence bandwidth of the channel is smaller than the bandwidth of the signal,It may be useless for increasing transmission power,Frequency Correlation 0.9 Bc = 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 multi

8、path 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-ante

9、nna 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 subframesOne subframe is 1ms 2 slots One slot is 0.5ms N resource

10、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

11、Access Channel,Physical Uplink Shared Channel,CQI 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

12、, 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 T

13、ransmission/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,Layer

14、ed 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 tran

15、smission/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 efficie

16、ncy, 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 covera

17、ge,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

18、 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,