3GPP LTE.ppt

An Introduction of
3GPP Long Term Evolution (LTE)
Mujib Tamboli

2
Reference
 http://www.tcs.com “LTE-Advanced: Future of Mobile Broadband,”
TATA Consultancy Services
 Takehiro Nakamura ,“Proposal for Candidate Radio Interface Technol
ogies for IMT‐Advanced Bas d on LTE Release 10 and Beyond,”
3GPP TSG‐RAN 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 Astély, Erik Dahlman, Anders Furuskär, Ylva Jading, Magnus
Lindström, 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 LTE-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) :
3GPP release 8~9
 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 Interference (ISI)
)
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y(t) : output signal
S(t) : input signal
S(t-m) : delayed m time input signal
n(t) : noise
y(t)
βS(t-m)
S(t)

8
Equalizers in Receiver
 Against Frequency Selective Fading
 Channel transform function Hc(f)
 Equalizers transform function Heq(f) (Receiver)
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c e
f
H 
 2
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Frequency 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 > 0.9
Bc = 1 / 50α α is r.m.s. delay spread

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

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 Channel
CQI report

20
LTE Release 8 Key Features (1/2)
 High spectral efficiency
 OFDM in Downlink
 Single‐Carrier 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,
15–20 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 throughput
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

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

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

3GPP LTE.ppt

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