Slides day one

Arief Hamdani Gunawan

1. Introduction to LTE 5. LTE Radio Procedures

2. OFDMA 6. LTE Uplink Physical Channels and
Signals
3. SC-FDMA
SC-
7. LTE Mobility
4. LTE Network and Protocol
8. LTE Test and Measurement

Session 1: Introduction to LTE
•Motivation
•Requirements
•Evolution of UMTS FDD and TDD
•LTE Technology Basics
•LTE Key Parameters
•LTE Frequency Bands

Motivation: LTE background story
the early days
Work on LTE was initiated as a
3GPP release 7 study item “Evolved
UTRA and UTRAN” in December
2004:
“With enhancements such as HSDPA
and Enhanced Uplink, the 3GPP
radio-access technology will be
highly competitive for several years.
However, to ensure competitiveness
in an even longer time frame, i.e. for
the next 10 years and beyond, a long
term evolution of the 3GPP radio-
access technology needs to be
considered.”
• Basic drivers for LTE have been:
– Reduced latency
– Higher user data rates
– Improved system capacity and
coverage
– Cost-reduction.

Major requirements for LTE
identified during study item phase in 3GPP
• Higher peak data rates: 100 Mbps (downlink) and 50 Mbps (uplink)
• Improved spectrum efficiency: 2-4 times better compared to 3GPP release
6
• Improved latency:
– Radio access network latency (user plane UE – RNC - UE) below 10 ms
– Significantly reduced control plane latency
• Support of scalable bandwidth: 1.4, 3, 5, 10, 15, 20 MHz
• Support of paired and unpaired spectrum (FDD and TDD mode)
• Support for interworking with legacy networks
• Cost-efficiency:
– Reduced CApital and OPerational EXpenditures (CAPEX, OPEX) including
backhaul
– Cost-effective migration from legacy networks
• A detailed summary of requirements has been captured in 3GPP TR
25.913 „Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-
UTRAN)”.

Evolution of UMTS FDD and TDD
driven by data rate and latency requirements

Note:
•High-Speed Downlink Packet Access (HSDPA, also known as High-Speed Data Packet Access)
•High-Speed Uplink Packet Access (HSUPA)
•High Speed Packet Access (HSPA)

3GPP Systems
Building on Releases

Release 99: Key Features
• Functional Freeze: Dec 1999
– CS and PS
– R99 Radio Bearers
– Multimedia Messaging Service (MMS)
– Location Services
• Functional Freeze: March 2000
– Basic 3.84 Mcps W-CDMA (FDD & TDD)
• Enhancements to GSM data (EDGE).
• Provides support for GSM/EDGE/GPRS/WCDMA radio-access networks.
• Majority of deployments today are based on Release 99.


– Enhancements 1.28 Mcps TDD (aka TD-SCDMA).
– Multimedia messaging support.
– First steps toward using IP transport in the core
network.

Megachips per second (Mcps) is a measure of the speed with which encoding elements,
called chips (not to be confused with microchips), are generated in Direct Sequence Spread
Spectrum (DSSS) signals. This speed is also known as the chipping rate. A speed of 1 Mcps is
equivalent to 1,000,000, or 106, chips per second.
Typical chipping rates in third-generation (3G) wireless systems are on the order of several
million chips per second. For example, in Wideband Code-Division Multiple Access (W-CDMA)
systems, the standard rate is 3.84 Mcps.

• Functional Freeze: June 2002
– HSDPA
– IMS: First phase of Internet Protocol Multimedia Subsystem (IMS).
– Adaptive Multi-Rate - Wideband (AMR-WB) Speech
– Full ability to use IP-based transport instead of just Asynchronous
Transfer Mode (ATM) in the core network.

Adaptive Multi-Rate Wideband (AMR-WB) is a patented speech coding standard developed
based on Adaptive Multi-Rate encoding, using similar methodology as Algebraic Code Excited
Linear Prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech
bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are
optimized for POTS wireline quality of 300–3400 Hz. AMR-WB was developed by Nokia and
VoiceAge and it was first specified by 3GPP.
AMR-WB is codified as G.722.2, an ITU-T standard speech codec, formally known as Wideband
coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). G.722.2
AMR-WB is the same codec as the 3GPP AMR-WB. The corresponding 3GPP specifications are TS
26.190 for the speech codec and TS 26.194 for the Voice Activity Detector.

3GPP architecture evolution towards flat architecture

Release 6 Release 7 Release 7 Release 8
Direct Tunnel Direct Tunnel and SAE and LTE
RNC in NB

GGSN GGSN GGSN SAE GW

SGSN SGSN SGSN MME

RNC RNC

NB NB RNC
eNB
NB
Control Plane User Plane


– HSUPA (E-DCH) / Enhanced Uplink
– Enhanced multimedia support through
Multimedia Broadcast/Multicast Services (MBMS).
– WLAN-UMTS Internetworking: Wireless Local Area
Network (WLAN) integration option
– Performance specifications for advanced
receivers.
– IMS enhancements. Initial VoIP capability.

– Evolved EDGE.
– Specifies HSPA+
– Radio enhancements to HSPA include 64 Quadrature Amplitude
Modulation (QAM) in the downlink DL and 16 QAM in the uplink.
– LTE and SAE Feasibility Study
– DL MIMO,
– IMS
– Performance enhancements, improved spectral efficiency, increased
capacity, and better resistance to interference.
– Continuous Packet Connectivity (CPC) enables efficient “always-on”
service and enhanced uplink UL VoIP capacity, as well as reductions in
call set-up delay for Push-to-Talk Over Cellular (PoC).
– Optimization of MBMS capabilities through the multicast/broadcast,
single-frequency network (MBSFN) function.

LTE Release 8: Key Features
– Further HSPA improvements / HSPA Evolution,
simultaneous use of MIMO and 64 QAM.
– Includes dual-carrier HSPA (DC-HSPA) where in
two WCDMA radio channels can be combined for
a doubling of throughput performance.
– LTE work item – OFOMA / SC-FDMA air interface
– SAE work item – new IP core network
– Specifies OFDMA-based 3GPP LTE.
– Defines EPC.

• High spectral efficiency
– OFDM in Downlink
• Robust against multipath interference
• High affinity to advanced techniques
– Frequency domain channel-dependent scheduling
– MIMO
– DFTS-OFDM(“Single-Carrier FDMA”) in Uplink
• Low PAPR DFTS-OFDM
• User orthogonality in frequency domain
DFTS-OFDM: DFT-spread OFDM.
– Multi-antenna application DFT: Discrete Fourier Transform.
• Very low latency
– Short setup time & Short transfer delay DFT-spread OFDM (DFTS-OFDM) is a transmission
– Short HO latency and interruption time scheme that can combine the desired properties
• Short TTI for uplink transmission i.e. :
• RRC procedure • Small variations in the instantaneous power of
the transmitted signal (‘single carrier’ property).
• Simple RRC states • Possibility for low-complexity high-quality
• Support of variable bandwidth equalization in the frequency domain.
– 1.4, 3, 5, 10, 15 and 20 MHz • Possibility for FDMA with flexible bandwidth
assignment.
Due to these properties, DFTS-OFDM has been
selected as the uplink transmission scheme for LTE,
which is the long-term 3G evolution.

LTE-Advanced: Key Requirements
LTE-Advanced shall be deployed as an evolution of LTE Release 8 and on new
bands.
LTE-Advanced shall be backwards compatible with LTE Release 8
Smooth and flexible system migration from Rel-8 LTE to LTE-Advanced

LTE-Advanced backward compatibility with LTE Rel-8

LTE-Advanced contains all features of LTE Rel-8&9 and
additional features for further evolution

LTE Rel-8 cell LTE-Advanced cell

LTE Rel-8 terminal LTE-Advanced terminal LTE Rel-8 terminal LTE-Advanced terminal
An LTE-Advanced terminal An LTE Rel-8 terminal can
can work in an LTE Rel-8 cell work in an LTE-Advanced cell

• Small enhancements from LTE Release 8 mainly for higher layer
– HeNB (Home eNode B)
• HeNB Access Mode
– Rel-8: Closed Access Mode
– Rel-9: Open and Hybrid Mode
• HeNB Mobility between HeNB and macro
– Rel-8: Out-bound HO
– Rel-9: in-bound and inter-CSG HO
– SON (self-organizing networks)
• Rel-8: Self configuration, Basic self-optimization
• Rel-9: RACH optimization, etc
– MBMS (Multimedia Broadcast Multicast Service)
• Rel-8: Radio physical layer specs
• Rel-9: Radio higher layer and NW interface specs
– LCS (Location Services)
• Rel-8: U-Plane solutions
• Rel-9: C-Plane solutions, e.g. OTDOA


• HSPA and LTE enhancements including
– HSPA dual-carrier operation in combination with
MIMO,
– EPC enhancements,
– femtocell support,
– support for regulatory features such as emergency
user-equipment positioning and Commercial
Mobile Alert System (CMAS), and
– evolution of IMS architecture.

LTE-Advanced: Motivation
1999 2011

Release 99 W-CDMA
3GPP aligned to ITU-R IMT process
Release 4 1.28Mcps TDD
Allows Coordinated approach to
WRC
Release 5 HSDPA 3GPP Releases evolve to meet:
• Future Requirements for IMT
Release 6 HSUPA, MBMS • Future operator and end-user
requirements
ITU-R M.1457 Release 7 HSPA+ (MIMO, HOM etc.)
IMT-2000 Recommendation
Release 8 LTE

Release 9 LTE enhancements

3 Gbps
ITU-R M.[IMT.RSPEC] Release 10 LTE-Advanced
64QA
IMT-Advanced Recommendation M
Release 11+ Further LTE
enhancements

8x8 MIMO 100MHz
BW

100 MHz
Support of Wider Bandwidth(Carrier Aggregation)
• Use of multiple component carriers(CC) to extend bandwidth up to 100 MHz
• Common physical layer parameters between component carrier and LTE Rel-8 carrier f
Improvement of peak data rate, backward compatibility with LTE Rel-8 CC
Advanced MIMO techniques
• Extension to up to 8-layer transmission in downlink
• Introduction of single-user MIMO up to 4-layer transmission in uplink
• Enhancements of multi-user MIMO
Improvement of peak data rate and capacity

Heterogeneous network and eICIC(enhanced Inter-Cell Interference
Coordination)
• Interference coordination for overlaid deployment of cells with different Tx power
Improvement of cell-edge throughput and coverage

Relay
• Type 1 relay supports radio backhaul and creates a separate cell and appear as Rel. 8 LTE eNB to
Rel. 8 LTE UEs
Improvement of coverage and flexibility of service area extension

Coordinated Multi-Point transmission and reception (CoMP)
• Support of multi-cell transmission and reception
Improvement of cell-edge throughput and coverage

LTE-Advanced meeting the requirements set by ITU’s IMT-Advanced project.
Also includes quad-carrier operation for HSPA+.

Spectrum Explosion in 3GPP
Recently standardized (Sep. 2011)
E-UTRA operating bands in 3GPP TS 36.101 • UMTS/LTE 3500MHz
• Extending 850 MHz Upper Band (814 – 849 MHz)

Spectrum to be standardized by Sep. 2012
• LTE-Advanced Carrier Aggregation of Band 3 and Band 7
• LTE Advanced Carrier Aggregation of Band 4 and Band 17
• LTE Advanced Carrier Aggregation Band 2 and Band 17
• LTE Advanced Carrier Aggregation in Band 41
• LTE Advanced Carrier Aggregation in Band 38
• LTE Downlink FDD 716-728MHz
• LTE E850 - Lower Band for Region 2 (non-US)
• LTE for 700 MHz digital dividend
• Study on Extending 850MHz
• Study on Interference analysis between 800~900 MHz bands
• Study on UMTS/LTE in 900 MHz band

E-UTRA operating bands
Duplex Mode: FDD

E-UTRA operating bands
Duplex Mode: TDD

3GPP TS 36.101
Evolved Universal Terrestrial Radio Access (E-UTRA);
User Equipment (UE) radio transmission and reception

The 2.6GHz band
120MHz separation duplex

FDD Uplink TDD FDD Downlink

2500 2570 2620 2690 MHz

Capacity
• Unique new band internationally harmonized
• Benefits of future economies of scale
• Capability to offer sufficient bandwidth per operator (20+20MHz)
• Avoid prejudicial interference, optimizing the spectrum use, through clear
definition of FDD (70+70MHz) and TDD (50MHz) spectrum blocks

700MHz band

748

758

803
703
698 806 MHz

5 45 10 45 3

Coverage
• Perfect fit to majority of countries in the region
• The alignment with Asia-Pacific permits the creation of a big market
(economies of scale, availability of terminals, etc.)
• Offer 2 continuous blocks of 45+45MHz (spectrum optimization, flexibility
on license process, better data transmission performance than US 700);
• Tool to bring the mobile broadband to rural and low density population
areas

2.6GHz + 700MHz

• Ideal combination for
– Coverage
– Capacity
– Convergence
– Device availability
– Roaming

• Convergence for countries with the legacy US band plan
(850/1900MHz) and the legacy European band plan (900/1800MHz)

• Note: no plans/proposals in 3GPP for LTE in 450Mhz band

(Dec/2012)
Further Downlink MIMO enhancements for LTE-Advanced
Addressing low-power modes, relay backhaul scenarios, and certain
practical antenna configurations
Provision of low-cost M2M UEs based on LTE
Studying LTE Coverage Enhancements
Network-Based Positioning Support for LTE
Further Self Optimizing Networks (SON) Enhancements
Mobility Robustness Optimisation (MRO) enhancements
Addressing Inter-RAT ping-pong scenarios
Carrier based HetNet Interference co-ordination for LTE
Carriers in same or different bands in HetNet environments with
mixture of different BTS types
Enhancements to Relays, Mobile Relay for LTE
RF core requirements for relays
Mobile relay: mounted on a vehicle wirelessly connected to the macro
cells
Interworking - 3GPP EPS and fixed BB accesses, M2M, Non voice emergency communications, 8 carrier
HSDPA, Uplink MIMO study

RAN Release 11 Priorities
• Short term prioritization for the end of 2011, between RAN#53 and RAN#54
• The next Plenary - RAN#54 (Dec. 2011) – will discuss priorities beyond March 2012

Latest RAN
H S P A Priority Work Items;
WID/SID Working Group
Core part: Uplink Transmit Diversity for HSPA – Closed Loop RP-110374 RAN 1

New WI: Four Branch MIMO transmission for HSDPA RP-111393 RAN 1

Core Part: eight carrier HSDPA RP-101419 RAN 1
Core part: Further Enhancements to CELL_FACH RP-111321 RAN 2
New WI: HSDPA Multiflow Data Transmission RP-111375 RAN 2

Proposed WID: Single Radio Voice Call Continuity from UTRAN/GERAN to E-UTRAN/HSPA RP-111334 RAN 3

Core part: Non-contiguous 4C-HSDPA operation RP-110416 RAN 4

New SID proposal: Introduction of Hand phantoms for UE OTA antenna testing RP-111380 RAN 4

Core part: Uplink Transmit Diversity for HSPA – Open Loop RP-110374 RAN 4

UE Over the Air (Antenna) conformance testing methodology- Laptop Mounted Equipment Free Space test RP-111381 RAN 4

RAN Release 11 Priorities
Latest RAN
L T E Priority Work Items;
WID/SID Working Group
WI/SI Coordinated Multi-Point Operation for LTE RP-111365 RAN 1
Core part: LTE Carrier Aggregation Enhancements RP-111115 RAN 1
Core part: Further Enhanced Non CA-based ICIC for LTE RP-111369 RAN 1
Study on further Downlink MIMO enhancements for LTE-Advanced RP-111366 RAN 1
Provision of low-cost MTC UEs based on LTE RP-111112 RAN 1
Proposed SI on LTE Coverage Enhancements RP-111359 RAN 1
Core part: LTE RAN Enhancements for Diverse Data Applications RP-111372 RAN 2
Study on HetNet mobility enhancements for LTE RP-110709 RAN 2
Enhancement of Minimization of Drive Tests for E-UTRAN and UTRAN RP-111361 RAN 2
New WI: Signalling and procedure for interference avoidance for in-device coexistence RP-111355 RAN 2
New WI proposal: RAN overload control for Machine-Type Communications RP-111373 RAN 2
Core part: Service continuity and location information for MBMS for LTE RP-111374 RAN 2
Core Part: Network-Based Positioning Support for LTE RP-101446 RAN 2
Further Self Optimizing Networks (SON) Enhancements RP-111328 RAN 3
Core part: Carrier based HetNet ICIC for LTE RP-111111 RAN 3
New WI: Network Energy Saving for E-UTRAN RP-111376 RAN 3
Proposed WID: LIPA Mobility and SIPTO at the Local Network RAN Completion RP-111367 RAN 3
Study on further enhancements for HNB and HeNB RP-110456 RAN 3
New SI: Mobile Relay for E-UTRA RP-111377 RAN 3
Enhanced performance requirement for LTE UE RP-111378 RAN 4
New SI: Study of RF and EMC Requirements for Active Antenna Array System (AAS) Base Station RP-111349 RAN 4
Study on Measurement of Radiated Performance for MIMO and multi-antenna reception for HSPA and LTE terminals RP-090352 RAN 4
New WI: E-UTRA medium range and MSR medium range/local area BS class requirements RP-111383 RAN 4
Core part: Relays for LTE (part 2) RP-110914 RAN 4
Study on Inclusion of RF Pattern Matching Technologies as a positioning method in the E-UTRAN RP-110385 RAN 4

Plans for LTE-A Release-12
• 3GPP workshop to be held June/2012
– Main themes and strategic directions to be set, e.g.:
• Extreme capacity needs and spectrum efficiency (‘challenge
Shannon’
• Flexibility, efficient handling of smartphone diversity
• Offloading to unlicensed radio technologies
• Power efficiency
• Prime areas of interest, e.g.:
– More optimized small cell deployments
– Carrier Aggregation Enhancements (inter-site, LTE/HSPA)
– Cognitive radio aspects
– SON and MDT enhancements
– Local Area optimizations

Session 2: OFDMA
•OFDM and OFDMA
•LTE Downlink
•OFDMA time-frequency multiplexing
•LTE Spectrum Flexibility
•LTE Frame Structure type 1 (FDD)
•LTE Frame Structure type 2(TDD)

OFDM
• Single Carrier Transmission (e.g. WCDMA)

• Orthogonal Frequency Division Multiplexing

OFDM Concept: Mengapa OFDM

• Sinyal OFDM (Orthogonal Frequency Division
Multiplexing) dapat mendukung kondisi NLOS (Non
Line of Sight) dengan mempertahankan efisiensi
spektral yang tinggi dan memaksimalkan spektrum
yang tersedia.
• Mendukung lingkungan propagasi multi-path.
• Scalable bandwidth: menyediakan fleksibilitas dan
potensial mengurangi CAPEX (capital expense).

36

OFDM Concept: NLOS Performance

37

OFDM Concept: Mutipath Propagation

• Sinyal-sinyal multipath datang pada waktu yang berbeda dengan amplitudo dan pergeseran fasa yang
berbeda, yang menyebabkan pelemahan dan penguatan daya sinyal yang diterima.
• Propagasi multipath berpengaruh terhadap performansi link dan coverage.
• Selubung (envelop) sinyal Rx berfluktuasi secara acak.
38

OFDM Concept: FFT

• Multi-carrier modulation/multiplexing technique
• Available bandwidth is divided into several subchannels
• Data is serial-to-parallel converted
• Symbols are transmitted on different subcarriers
39

OFDM Concept: IFFT

Basic ideas valid for various multicarrier techniques:
• OFDM: Orthogonal Frequency Division Multiplexing
• OFDMA: Orthogonal Frequency Division Multiple Access

40

OFDM Concept: Single-Carrier Vs. OFDM

Single-Carrier Mode: OFDM Mode:
• Serial Symbol Stream Used to Modulate a • Each Symbol Used to Modulate a Separate
Single Wideband Carrier Sub-Carrier
• Serial Datastream Converted to Symbols
(Each Symbol Can Represented 1 or More
Data Bits) 41

OFDM Concept: Single-Carrier Vs. OFDM

Single-Carrier Mode OFDM Mode
• Dotted Area Represents Transmitted Spectrum
• Solid Area Represents Receiver Input

• OFDM mengatasi delay spread, multipath dan ISI (Inter Symbol Interference) secara efisien sehingga
dapat meningkatkan throughput data rate yang lebih tinggi.
• Memudahkan ekualisasi kanal terhadap sub-carrier OFDM individual, dibandingkan terhadap sinyal
single-carrier yang memerlukan teknik ekualisasi adaptif lebih kompleks. 42

OFDM Concept: Motivation for Multi-carrier Approaches

• Multi-carrier transmission offers various advantages over
traditional single carrier approaches:
– Highly scalable
– Simplified equalizer design in the frequency domain, also in cases of
large delay spread
– High spectrum density
– Simplified the usage of MIMO
– Good granularity to control user data rates
– Robustness against timing errors
• Weakness of multi-carrier systems:
– Increased peak to average power ratio (PAPR)
– Impairments due to impulsive noise
– Impairments due to frequency errors

43

OFDM Concept: Peak to Average Power Ratio (PAPR)

• PAPR merupakan ukuran dari fluktuasi tepat sebelum amplifier.
• PAPR sinyal hasil dari mapping PSK base band sebesar 0 dB karena semua symbol mempunyai daya yang
sama.
• Tetapi setelah dilakukan proses IDFT/IFFT, hasil superposisi dari dua atau lebih subcarrier dapat
menghasilkan variasi daya dengan nilai peak yang besar.
• Hal ini disebabkan oleh modulasi masing-masing subcarrier dengan frekuensi yang berbeda sehingga
apabila beberapa subcarrier mempunyai fasa yang koheren, akan muncul amplituda dengan level yang
jauh lebih besar dari daya sinyalnya. 44

OFDM Concept: Peak to Average Power Ratio (PAPR)

• Nilai PAPR yang besar pada OFDM membutuhkan amplifier dengan dynamic range yang lebar untuk
mengakomodasi amplitudo sinyal.
• Jika hal ini tidak terpenuhi maka akan terjadi distorsi linear yang menyebabkan subcarrier menjadi tidak
lagi ortogonal dan pada akhirnya menurunkan performansi OFDM.
45

Tipe Sub-Carrier OFDM

Data Sub-carriers
• Membawa simbol BPSK, QPSK, 16QAM, 64QAM
Pilot Sub-carriers
• Untuk memudahkan estimasi kanal dan demodulasi koheren pada receiver.
Null Subcarrier
• Guard Sub-carriers
• DC Sub-carrier 46

Guard Interval (Cyclic Prefix)

• Untuk mengatasi multipath delay spread
47
• Guard Interval (cyclic prefix) : 1/4, 1/8, 1/16 or 1/32

OFDM Transceiver

48

OFDM & OFDMA
OFDM OFDMA
• Semua subcarrier dialokasikan untuk satu • Subcarrier dialokasikan secara fleksibel
user untuk banyak user tergantung pada kondisi
• Misal : 802.16-2004 radio.
• Misal : 802.16e-2005 dan 802.16m

49

OFDM Parameters used in WiMAX

50

Difference between OFDM and OFDMA

• OFDM allocates users in time • OFDMA allocates users in time
domain only and frequency domain

OFDMA time-frequency multiplexing

LTE Downlink Physical Layer Design: Physical Resource

The physical resource can be seen as
a time-frequency grid

• LTE uses OFDM (Orthogonal Frequency Division Multiplexing) as its radio technology in downlink
• In the uplink LTE uses a pre=coded version of OFDM, SC-FDMA (Single Carrier Frequency Division
Multiple Access) to reduced power consumption
53

LTE Downlink Resource Grid

• Suatu RB (resource block) terdiri dari 12 subcarrier pada suatu
durasi slot 0.5 ms.

• Satu subcarrier mempunyai BW 15 kHz, sehingga menjadi 180
kHz per RB.

54

Parameters for DL generic frame structure

Bandwidth (MHz) 1.25 2.5 5.0 10.0 15.0 20.0

Subcarrier bandwidth (kHz) 15

Physical resource block (PRB)
180
bandwidth (kHz)

Number of available PRBs 6 12 25 50 75 100

55

Parameters for DL generic frame structure

Transmission BW 1.25 MHz 2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Sub-frame duration 0.5 ms

Sub-carrier spacing 15 kHz

192 MHz
7.68 MHz 15.36 MHz 23.04 MHz 30.72 MHz
Sampling frequency (1/2x3.84 3.84 MHz
(2x3.84 MHz) (4x3.84 MHz) (6x3.84 MHz) (8x3.84 MHz)
MHz)

FFT size 128 256 512 1024 1536 2048

OFDM sym per slot
7/6
(short/long CP)

(4.69/9) x 6, (4.69/18) x 6, (4.69/36) x 6, (4.69/72) x 6, (4.69/108) x 6, (4.69/144) x 6,
Short
CP length (5.21/10) x 1 (5.21/20) x 1 (5.21/40) x 1 (5.21/80) x 1 (5.21/120) x 1 (5.21/160) x 1
(usec/
samples)
Long (16.67/32) (16.67/64) (16.67/128) (16.67/256) (16.67/384) (16.67/512)

56

LTE – Spectrum Flexibility

• LTE physical layer supports any bandwidth from 1.4 MHz to 20
MHz in steps of 180 kHz (resource block).
• Current LTE specification supports a subset of 6 different
system bandwidths.
• All UEs must support the maximum bandwidth of 20 MHz.

Case Study
LTE Signal Spectrum (20 MHz case)

• The LTE standard uses an over-sized LTE. The actual used bandwidth is controlled by the number of used
subcarriers. 15 kHz subcarrier spacing is the constant factor!
• 18 MHz out of 20 MHz is used for data, 1 MHz on each side is used as guard band.
• LTE used spectrum radio = 90%
• WiMAX used spectrum radio = 82% 59

TDD & FDD

• Time Division Duplex (TDD)
• Frequency Division Duplex (FDD)
• Durasi Frame : 2.5 - 20ms 60

Generic LTE Frame Structure type 1 (FDD)
Tf = 307200 x Ts = 10 ms

Tslot = 15360 x Ts = 0.5 ms

• Untuk struktur generik, frame radio 10 ms dibagi dalam 20 slot yang sama berukuran 0.5 ms.
• Suatu sub-frame terdiri dari 2 slot berturut-turut, sehingga satu frame radio berisi 10 sub-frame.
• Ts menunjukkan unit waktu dasar yang sesuai dengan 30.72 MHz.
• Struktur frame tipe-1 dapat digunakan untuk transmisi FDD dan TDD.
61

LTE Frame Structure type 1 (FDD)

• 2 slots form one subframe = 1 ms
• For FDD, in each 10 ms interval, all 10 subframes are available for downlink transmission and uplink transmissions.
• For TDD, a subframe is either located to downlink or uplink transmission. The 0th and 5th subframe in a radio frame is
always allocated for downlink transmission.
62

Downlink LTE Frame Structure type 1 (FDD)

Generic LTE Frame Structure type 2 (TDD)

• Struktur frame tipe-2 hanya digunakan untuk transmisi TDD.
• Slot 0 dan DwPTSdisediakan untuk transmisi DL, sedangkan slot 1 dan UpPTS disediakan untuk transmisi
UL.
64

LTE Frame Structure type 2 (TDD)

65

Mobile WiMAX Frame Structure

66

LTE Frame Structure type 2 (TDD)

DL Peak rates for E-UTRA FDD/TDD
frame structure type 1
Downlink
64 QAM
Assumptions Signal overhead for reference signals and
control channel occupying one OFDM symbol
Unit Mbps in 20 MHz b/s/Hz
Requirement 100 5.0
2x2 MIMO 172.8 8.6
4x4 MIMO 326.4 16.3

UL Peak rates for E-UTRA FDD/TDD
Uplink
Single TX UE
Assumptions Signal overhead for reference signals and control
channel occupying 2RB
Unit Mbps in 20 MHz b/s/Hz
Requirement 50 2.5
16QAM 57.6 2.9
64QAM 86.4 4.3

Peak rates for E-UTRA TDD

Downlink Uplink
Single TX UE,
Assumptions 64 QAM, R=1
64 QAM, R=1
Mbps Mbps
Unit b/s/Hz b/s/Hz
in 20 MHz in 20 MHz
Requirement 100 5.0 50 2.5
2x2 MIMO in DL 142 7.1
62.7 3.1
4x4 MIMO in DL 270 13.5

3GPP TR 25.912
Technical Specification Group Radio Access Network;
Feasibility study for
evolved Universal Terrestrial Radio Access (UTRA)
and Universal Terrestrial Radio Access Network (UTRAN)

Release Freeze meeting Freeze date ::
Rel-7 RP-33 2006-09-22 ::
event version available
RP-27 0.0.0 2005-03-03
RP-31 0.0.4 2006-03-20
draft 0.1.0 2006-03-20
draft 0.1.1 2006-03-20
post RP-31 0.1.2 2006-03-30
R3-51b 0.1.3 2006-05-02
draft post Shanghai 0.1.4 2006-05-22
draft 0.1.5 2006-07-10
draft 0.1.6 -
draft 0.1.7 2006-05-29
RP-32 0.2.0 2006-06-12
RP-32 7.0.0 2006-06-23
RP-33 7.1.0 2006-10-18
RP-36 7.2.0 2007-08-13

3GPP TR 25.912
Feasibility study for
evolved Universal Terrestrial Radio Access (UTRA)
and Universal Terrestrial Radio Access Network (UTRAN)
Rel-8 SP-42 2008-12-11 :: . ETSI
event version available remarks
RTR/TSGR-
SP-42 8.0.0 2009-01-02 Upgraded unchanged from Rel-7
0025912v800
Upgraded to Rel-9 with no technical change to enable
Rel-9 SP-46 2009-12-10 :: reference related to ITU-R IMT-Advanced submission ETSI
(reference in 36.912). .
RTR/TSGR-
RP-45 9.0.0 2009-10-01 Technically identical to v8.0.0
0025912v900
Upgraded from previous Release without technical
Rel-10 SP-51 2011-03-23 :: ETSI
change .
RTR/TSGR-
SP-51 10.0.0 2011-04-06 Automatic upgrade from previous Release version 9.0.0
0025912va00
Upgraded from previous Release without technical
Rel-11 SP-57 2012-09-12 :: ETSI
change .
SP-57 11.0.0 2012-09-26 Automatic upgrade from previous Release version 10.0.0 -

Session 3: SC-FDMA
•Introduction SC-FDMA and UL frame structure
•How to generate SC-FDMA
•How does SC-FDMA signal look like
•SC-FDMA Signal Generation
•SC-FDMA PAPR
•SC-FDMA Parameterization

LTE Uplink Transmission Scheme: SC-FDMA
• Pemilihan OFDMA dianggap optimum untuk memenuhi persyaratan LTE
pada arah downlink, tetapi OFDMA memiliki properti yang kurang
menguntungkan pada arah Uplink.
• Hal tsb terutama disebabkan oleh lemahnya peak-to-average power ratio
(PAPR) dari sinyal OFDMA, yang mengakibatkan buruknya coverage uplink.
• Oleh karena itu, skema transmisi Uplink LTE untuk mode FDD maupun TDD
didasarkan pada SC-FDMA, yang mempunyai properti PAPR lebih baik.
• Pemrosesan sinyal SC-FDMA memiliki beberapa kesamaan dengan
pemrosesan sinyal OFDMA, sehingga parameter-parameter DL dan UL
dapat diharmonisasi.
• Untuk membangkitkan sinyal SC-FDMA, E-UTRA telah memilih DFT-
spread-OFDM (DFT-s-OFDM).

74

OFDMA and SC-FDMA
• The symbol mapping
in OFDM happens in
the frequency
domain.
• In SC-FDMA, the
symbol mapping is
done in the time
domain.
• Appropriate
subscriber mapping
in the frequency
domain allows to
control the PAPR.
• SC-FDMA enable
frequency domain
equalizer approaches
like OFDMA

75

Comparison of how OFDMA and SC-FDMA
transmit a sequence of QPSK data symbols

76

Comparison of how OFDMA and SC-FDMA
transmit a sequence of QPSK data symbols
Creating the time-
domain waveform of an
SC-FDMA symbol

Baseband and shifted
frequency domain
representations of an
SC-FDMA symbol

77

How to generate SC-FDMA?
• DFT “pre-coding” is performed on modulated data symbols to
transform them into frequency domain,
• Sub-carrier mapping allows flexible allocation of signal to available
sub-carriers,
• IFFT and cyclic prefix (CP) insertion as in OFDM,

• Each subcarrier carries a portion of superposed DFT spread data
symbols, therefore SC-FDMA is also referred to as DFT-spread-
OFDM (DFT-s-OFDM).

How does a SC-FDMA signal look like?

• Similar to OFDM signal, but…
– …in OFDMA, each sub-carrier only carries information
related to one specific symbol,
– …in SC-FDMA, each sub-carrier contains information of ALL
transmitted symbols.

SC-FDMA signal generation
Localized vs. distributed FDMA

SC-FDMA – Peak-to-average Power Ratio (PAPR)

Comparison of CCDF of PAPR for IFDMA, LFDMA, and OFDMA with M = 256 system subcarriers,
N=64 subcarriers per users, and a = 0.5 roll factor; (a) QPSK; (b) 16-QAM

Source:
H.G. Myung, J.Lim, D.J. Goodman “SC-FDMA for Uplink Wireless Transmission”,
IEEE VEHICULAR TECHNOLOGY MAGAZINE, SEPTEMBER 2006

SC-FDMA parameterization (FDD and TDD)
LTE FDD
•Same as in downlink

TD-LTE
•Usage of UL depends on the selected UL-DL configuration (1 to 8), each
configuration offers a different number of subframes (1ms) for uplink
transmission,
•Parameterization for those subframes, means number of SC-FDMA symbols
same as for FDD and depending on CP,
82

Improved UL Performance
SC-FDMA compared to ordinary OFDM

Single-carrier transmission in uplink enables low PAPR that gives more 4 dB better link
budget and reduced power consumption compared to OFDM
83

LTE Uplink SC-FDMA Physical Layer Parameters

84

Physical Channel Processing

• Scrambling: Scramble binary information
• Modulation Mapper: Maps groups of 2, 4, or 6 bits onto QPSK, 16QAM, 64QAM symbol constellation points
• Transform Precoder: Slices the input data vector into a set of symbol vectors and perform DFT transformation.
• Resource Element Mapper: Maps the complex constellation points into the allocated virtual resource blocks
and performs translation into physical resource blocks.
• SC-FDMA Signal Generation: Performs the IFFT processing to generate final time domain for transmission.

85

SC-FDMA and OFDMA Signal Chain
Have a High Degree of Functional Commonality

Cyclic
Single Carrier S/P Symbol M-Point Subcarrier N-Point
Bit Prefix &
RFE
Constellation Convert Block DFT Mapping IDFT
Stream Pulse
Mapping
Shaping

Channel

Const. Freq Cyclic
Bit SC S/P Symbol M-Point N-Point
De-map Domain Prefix RFE
Stream Detector Convert Block IDFT DFT
Equalizer Removal

Functions Common to OFDMA and SC-FDMA

SC-FDMA Only

86

Session 4: Network and Protocol
•Network architecture
•Protocol Stack – User plane
•Protocol Stack – Control plane
•Mapping between logical and transport channel
•LTE UE Categories

LTE Network Architecture
UMTS 3G: UTRAN
EPC

GGSN MME MME
S-GW / P-GW
P- S-GW / P-GW
P-

SGSN

RNC RNC

eNB eNB
eNB eNB
NB NB NB NB E-UTRAN

UMTS : Universal Mobile Telecommunications System EPC ; Evolved Packet Core
UTRAN : Universal Terrestrial Radio Access Network MME : Mobility Management Entity
GGSN : Gateway GPRS Support Node S-GC : Serving Gateway
GPRS: General Packet Radio Service P-GW : PDN Gateway
SGSN : Serving GPRS Support Node PDN : Packet Data Network
RNC: Radio Network Controller eNB : E-UTRAN Node B / Evolved Node B
NB: Node B E-UTRAN ; Evolved-UTRAN

Simplified LTE network elements and interfaces
3GPP TS 36.300 : Overall Architecture
EPC: Evolved Packet Core
Radio Side: LTE – Long Term Evolution
EPC
• Improvements in spectral efficiency, user
MME throughput, latency.
MME
• Simplification of the radio network
S-GW / P-GW
P- S-GW / P-GW
P-
• Efficient support of packet services
• Main Components:
• MME = Manages mobility, UE identity, and
security parameters.
• S-GW = Node that terminates the interface
S1 towards E-UTRAN.
• P-GW = Node that terminates the interface
towards PDN

eNB X2 eNB E-UTRAN : Evolved-UTRAN
eNB eNB Network Side : SAE – System Architecture Evolution
E-UTRAN • Improvement in latency, capacity, throughput
• Simplification of the core network
• Optimization for IP traffic services
• Simplified support and handover to non-3GPP
access technologies
• Main Components:
• eNB = All radio interface-related functions

EPS Network Elements
S6a

Gx Rx
S1-MME
MME

Operator’s
LTE-Uu S1-U S5 / S8 SGi IP Services
S-GW P-GW
(e.g. IMS, PSS,
eNB etc,)
UE E-UTRAN EPC

• UE, E-UTRAN and EPC together represent the Internet Protocol (IP) Connectivity Layer.
• This part of the system is also called the Evolved Packet System (EPS).
• The main function of this layer is to provide IP based connectivity, and it is highly optimized for that purpose only.
• All services will be offered on top of IP, and circuit switched nodes and interfaces seen in earlier 3GPP
architectures are not present in E-UTRAN and EPC at all.
• IP technologies are also dominant in the transport, where everything is designed to be operated on top of IP
transport.

System architecture for E-UTRAN only network

Services

• The IP Multimedia Sub-System
(IMS) is a good example of service
machinery that can be used in the
Services Connectivity Layer to
provide services on top of the IP
connectivity provided by the
lower layers.
• For example, to support the voice
service, IMS can provide Voice
over IP (VoIP) and
interconnectivity to legacy circuit
switched networks PSTN and
ISDN through Media Gateways it
controls.

EPC
• Functionally the EPC is equivalent to the packet
switched domain of the existing 3GPP networks.
• Significant changes in the arrangement of functions
and most nodes and the architecture in this part
should be considered to be completely new.
• SAE GW represents the combination of the two
gateways, Serving Gateway (S-GW) and Packet Data
Network Gateway (P-GW) defined for the UP
handling in EPC.
• Implementing them together as the SAE GW
represents one possible deployment scenario, but
the standards define the interface between them,
and all operations have also been specified for
when they are separate.
• The Basic System Architecture Configuration and its
functionality are documented in 3GPP TS 23.401.
• We will learn the operation when the S5/S8
One of the big architectural changes in the interface uses the GTP protocol. However, when
core network area is that the EPC does the S5/S8 interface uses PMIP, the functionality for
not contain a circuit switched domain, and these interfaces is slightly different, and the Gxc
no direct connectivity to traditional circuit interface also is needed between the Policy and
switched networks such as ISDN or PSTN Charging Resource Function (PCRF) and S-GW.
is needed in this layer.

E-UTRAN
• The development in E-UTRAN is
concentrated on one node, the
evolved Node B (eNodeB).
• All radio functionality is collapsed
there, i.e. the eNodeB is the
termination point for all radio
related protocols.
• As a network, E-UTRAN is simply
a mesh of eNodeBs connected to
neighbouring eNodeBs with the
X2 interface.

User Equipment
• UE is the device that the end user uses for
communication.
• Typically it is a hand held device such as a smart
phone or a data card such as those used
currently in 2G and 3G, or it could be
embedded, e.g. to a laptop.
• UE also contains the Universal Subscriber
Identity Module (USIM) that is a separate
module from the rest of the UE, which is often
called the Terminal Equipment (TE).
• USIM is an application placed into a removable
smart card called the Universal Integrated
Circuit Card (UICC).
• USIM is used to identify and authenticate the
Functionally the UE is a platform for communication user and to derive security keys for protecting
applications, which signal with the network for setting the radio interface transmission.
up, maintaining and removing the communication links • Maybe most importantly, the UE provides the
the end user needs.
This includes mobility management functions such as
user interface to the end user so that
handovers and reporting the terminals location, and in applications such as a VoIP client can be used to
these the UE performs as instructed by the network. set up a voice call.

User Equipment Capabilities

1G Analog
2G Digital
3G Packets
4G True
Broadband

• Support Spectrum flexibility
– Flexible bandwidth 1.4 MHz 20 MHz
– New and existing bands

Downlink physical layer parameter values
set by the field UE-Category
UE Category Maximum number of Maximum number of Total number of Maximum number of
DL-SCH transport block bits of a DL-SCH soft channel bits supported layers for
bits received within a transport block spatial multiplexing
TTI (Note) received within a TTI in DL
Category 1 10296 10296 250368 1
Category 2 51024 51024 1237248 2
Category 3 102048 75376 1237248 2
Category 4 150752 75376 1827072 2
Category 5 299552 149776 3667200 4
Category 6 301504 149776 (4 layers) 3654144 2 or 4
75376 (2 layers)
Category 7 301504 149776 (4 layers) 3654144 2 or 4
75376 (2 layers)
Category 8 2998560 299856 35982720 8
NOTE: In carrier aggregation operation, the DL-SCH processing capability can be shared by the UE with that of MCH
received from a serving cell. If the total eNB scheduling for DL-SCH and an MCH in one serving cell at a given
TTI is larger than the defined processing capability, the prioritization between DL-SCH and MCH is left up to
UE implementation.
TTI = Transmission Time Interval

MIMO = Multiple Input Multiple Output 3GPP TS 36.306 V11.1.0 (2012-09)
UL-SCH = Uplink Shared Channel 3rd Generation Partnership Project;
DL-SCH = Downlink Shared Channel Technical Specification Group Radio Access Network;
UE = User Equipment Evolved Universal Terrestrial Radio Access (E-UTRA);
TTI = Transmission Time Interval
User Equipment (UE) radio access capabilities

Transmission Time Interval

• Transmission Time Interval: Transmission Time Interval is
defined as the inter-arrival time of Transport Block Sets, i.e.
the time it shall take to transmit a Transport Block Set.
• Transport Block Set: Transport Block Set is defined as a set of
Transport Blocks that is exchanged between L1 and MAC at
the same time instance using the same transport channel. An
equivalent term for Transport Block Set is “MAC PDU Set”.
• Transport Block: Transport Block is defined as the basic data
unit exchanged between L1 and MAC. An equivalent term for
Transport Block is “MAC PDU”.

3GPP TR 21.905 V11.2.0 (2012-09)
3rd Generation Partnership Project;
Technical Specification Group Services and System Aspects;
Vocabulary for 3GPP Specifications
(Release 11)

Uplink physical layer parameter values
set by the field UE-Category

UE Category Maximum number of UL- Maximum number of Support for 64QAM
SCH transport block bits bits of an UL-SCH in UL
transmitted within a TTI transport block
transmitted within a TTI
Category 1 5160 5160 No
Category 5 75376 75376 Yes
Category 7 102048 51024 No
Category 8 1497760 149776 Yes

3GPP TS 36.306 V11.1.0 (2012-09)
3rd Generation Partnership Project;
Evolved Universal Terrestrial Radio Access (E-UTRA);
User Equipment (UE) radio access capabilities

Functional split between E-UTRAN and Evolved Packet Core
eNB E-UTRAN
aGW
eNodeB
• Paging origination
• All Radio-related issues
• LTE_IDLE mode management
• Decentralized mobility
• Ciphering of the user plane
management
• Header Compression (ROHC)
• MAC and RRM
• Simplified RRC

S1
aGW

Internet
The E-UTRAN consists of eNBs, providing: RRM : Radio Resource Management
• The E-UTRA U-plane (RLC/MAC/PHY) and RRC: Radio Resource Control
• The C-plane (RRC) protocol terminations MAC : Medium Access Control
ROHC: RObust Header Compression
towards the UE. RLC: Radio Link Control
• The eNBs interface to the aGW via the S1 PHY: Physical Layer

Protocol
eNB E-UTRAN
Inter Cell RRM MME
RB Cont. NAS Security
Connection Mobility Cont. EPC
Idle State Mobility Handling
Radio Admission Cont.
eNB Measurement EPS Bearer Cont.
Configuration & Provision
Dynamic Resource
Allocation (Scheduler) SAE GW
RRC
S-GW P-GW
PDCP UE IP Address
Mobile Anchoring
RLC Allocation
S1
MAC Packet Filtering
PHY
Internet
RRM : Radio Resource Management NAS : Non Access Stratum
RB : Radio Bearer EPS : Evolved Packet System
RRC: Radio Resource Control UE : User Equipment
PDCP : Packet Data Convergence Protocol IP : Internet Protocol
RLC : Radio Link Control
MAC : Medium Access Control
PHY : Physical Layer

LTE Control Plane
UE eNB aGW Non Access Stratum (NAS) is a
NAS NAS functional layer in UMTS
protocol stack between Core
RRC RRC S1 Network and User Equipment
PDCP PDCP (UE).
The layer supports signaling and
RLC RLC
traffic between two elements.
MAC MAC
PHY PHY

LTE User Plane
Packet Data Convergence Protocol
(PDCP) is a one of the layers of
Radio Traffic Stack in UMTS
UE eNB aGW and perform as IP header
IP IP compression and
decompression, transfer of
PDCP PDCP S1 user data and maintenance of
RLC RLC sequence numbers for Radio
Bearers which are configured
MAC MAC for lossless Serving Radio
PHY PHY Networks Subsystems (SRNS)
relocation.

LTE Protocol Stacks (UE and eNB)
RRC: Radio Resource Control

Control-Plane User-Plane PDCP : Packet Data Convergence Protocol
RLC : Radio Link Control
L3 RRC MAC : Medium Access Control
PHY : Physical Layer

Radio Bearers
PDCP
L2
RLC

Logical Channels
MAC

Transport Channels
L1 PHY:
Physical Channels
Physical Signals

Control plane protocol stack in EPS

The topmost layer in the CP is the Non-Access Stratum (NAS), which consists of two
separate protocols that are carried on direct signaling transport between the UE
and the MME.
The content of the NAS layer protocols is not visible to the eNodeB, and the eNodeB is
not involved in these transactions by any other means, besides transporting the
messages, and providing some additional transport layer indications along with the
messages in some cases.

NAS layer protocols
The NAS layer protocols are:
• EPS Mobility Management (EMM): The EMM protocol is responsible for handling
the UE mobility within the system. It includes functions for attaching to and
detaching from the network, and performing location updating in between. This is
called Tracking Area Updating (TAU), and it happens in idle mode. Note that the
handovers in connected mode are handled by the lower layer protocols, but the
EMM layer does include functions for re-activating the UE from idle mode. The UE
initiated case is called Service Request, while Paging represents the network
initiated case. Authentication and protecting the UE identity, i.e. allocating the
temporary identity GUTI to the UE are also part of the EMM layer, as well as the
control of NAS layer security functions, encryption and integrity protection.
• EPS Session Management (ESM): This protocol may be used to handle the bearer
management between the UE and MME, and it is used in addition for E-UTRAN
bearer management procedures. Note that the intention is not to use the ESM
procedures if the bearer contexts are already available in the network and E-
UTRAN procedures can be run immediately. This would be the case, for example,
when the UE has already signaled with an operator affiliated. Application Function
in the network, and the relevant information has been made available through the
PCRF.

User plane protocol stack in EPS

The UP includes the layers below the end user IP, i.e. these protocols form the Layer 2
used for carrying the end user IP packets.
The protocol structure is very similar to the CP.
This highlights the fact that the whole system is designed for generic packet data
transport, and both CP signaling and UP data are ultimately packet data. Only the
volumes are different.

Summary of interfaces and protocols in Basic
System Architecture configuration

LTE Downlink Logical Channels 1

LTE Downlink Logical Channels 2

LTE Downlink Transport Channels 1

LTE Downlink Transport Channels 2

LTE Downlink Physical Channels 1

LTE Downlink Physical Channels 2

End of

Thank You

See you again at

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