Long Term Evolution -A Communication Standard

Mobile broadband is becoming a reality.

It is estimated that 1.8 billion people will

have broadband by 2012.

Majority of these are served by HSPC.

Replacing HSPC by LTE, the user experience would

be even more better.

OVERVIEW

Latest 3GPP standard.

Downlink speed up to 150 Mbps.

Uplink speed up to 50 Mbps.

Provide apps like Interactive TV, Voice over

IP, Streaming multimedia, MMOG and

much more.

LTE

Goals of LTE

Data rate

Throughput

Latency

Bandwidth

Interworking

MBMS

Cost

Mobility

Single Carrier Modulation and Channel

Equalization.

Orthogonal Frequency Division

Multiplexing (OFDM).

Single Carrier Frequency Domain Multiple

Access (SC-FDMA).

BASIC CONCEPTS

SC modulation introduces Multipath

Distortion.

Single Carrier Modulation

Results of Multipath distortion

Results of Multipath distortion

Two methods of Channel Equalization:

1. Channel Inversion

2. Rake Equalization

Channel equalizer implementation

becomes increasingly complex as data

rates increase.

Channel Equalization

Equalizer Topology

OFDM - Transmitter

OFDM - Receiver

Elimination of ISI

SC-FDMA

Radio Access Network Architecture

Radio Protocol Architecture

Architecture

Radio Access Network Architecture

Radio Protocol Architecture

Block Diagram

Coding and Modulation

Resource Mapping

Multi-Antenna Transmission

Downlink Transmission Scheme

Block Diagram

Cyclic Redundancy Check (CRC)

Channel Coding, Rate Matching, and HARQ

Interleaving

Modulation

Coding and Modulation

Resource Mapping

Multi-Antenna Transmission

Spatial Multiplexing

Spatial Multiplexing

with CDD

Beamforming

Beamforming with

CDD

Transmit Diversity

Block Diagram

Coding and Modulation

Resource Mapping

Multi-Antenna Transmission

Uplink Transmission Scheme

Block Diagram

Cyclic Redundancy Check (CRC)

Channel Coding, Rate Matching, and HARQ

Interleaving

Modulation

Coding and Modulation

Resource Mapping

LTE is more of a revolution than an evolution.

Wider bandwidths, multicarrier modulation,

multiple antennas and packet scheduling are

the technologies finding exploitation in LTE.

Researches are going on to upgrade LTE as

‘LTE-ADVANCED’.

LTE-Advanced are challenging, both in terms

of the timescale and expected data rates and

performance.

Beyond LTE

Designed to operate in scarce and valuable

licensed spectrum.

Well positioned to meet the requirements of next-

generation mobile networks.

High performance, mass-market mobile

broadband services, through a combination of high

bit-rates and system throughput – in both the

uplink and downlink – with low latency.

Conclusion

LTE enabling technologies – OFDM

• R. van Nee and R. Prasad, OFDM for Wireless Multimedia Communications,

Artech House, 2000. – SC-FDMA

• H. G. Myung et al., “Single Carrier FDMA for Uplink Wireless Transmission,” IEEE

Vehicular Technology Mag., vol. 1, no. 3, Sep. 2006.• http://hgmyung.googlepages.com/scfdma

References and Resources

3GPP LTE – Spec

• http://www.3gpp.org/ftp/Specs/html-info/36-series.htm• http://www.3gpp.org/ftp/Specs/html-info/25814.htm (old)

– E. Dahlman et al., 3G Evolution: HSPA and LTE for MobileBroadband, Academic Press, 2007

– H. Ekström et al., “Technical Solutions for the 3G Long-TermEvolution,” IEEE Commun. Mag., vol. 44, no. 3, March 2006, pp.38-45

– 3G Americas, “Mobile Broadband: The Global Evolution ofUMTS/HSPA - 3GPP Release 7 and Beyond" available at

http://www.3gamericas.org/pdfs/UMTS_Rel7_Beyond_Dec2006.pdf

– http://www.LTEwatch

References and Resources

tTHANK YOU