Just overview about basic LTE, the reference come from Huawei and Floatway

1. Ekstensi TelkomTelekomunikasi Unjani
Basic LTE Overview
LTE For Indonesia
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Jaringan Mobile & Ad-HOC
Program Studi Strata I Telekomunikasi
Jurusan Teknik Elektro
Disusun oleh :
M. Toenof Abdulghani 2212132073

2. Ekstensi TelkomTelekomunikasi Unjani 2
Introductions
Network Architecture
LTE Technology
Throughput Calculation

3. Ekstensi TelkomTelekomunikasi Unjani
Introductions
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4. Ekstensi TelkomTelekomunikasi Unjani
2G & 3G Radio Technology Evolution
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5. Ekstensi TelkomTelekomunikasi Unjani
Wireless Broadband Technology Evolution
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6. Ekstensi TelkomTelekomunikasi Unjani
Towards to 4G
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7. Ekstensi TelkomTelekomunikasi Unjani
NETWORK ARCHITECTURE
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8. Ekstensi TelkomTelekomunikasi Unjani
4G Architecture
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EPC : Evolved Packet Core
MME : Mobility Management Entity
S-GW : Serving Gateway
P-GW : PDN Gateway
PDN : Packet Data Network
eNB : E-UTRAN Node B / Evolved Node B
E-UTRAN : Evolved-UTRAN

9. Ekstensi TelkomTelekomunikasi Unjani
Logical High Level Architecture for The Evolved System
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10. Ekstensi TelkomTelekomunikasi Unjani
LTE Technology
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11. Ekstensi TelkomTelekomunikasi Unjani
FDMA TDMA CDMA and OFDMA
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12. Ekstensi TelkomTelekomunikasi Unjani
OFDM
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13. Ekstensi TelkomTelekomunikasi Unjani
OFDM
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Introduction
 OFDM （Orthogonal Frequency Division Multiplexing） is a
modulation multiplexing scheme. The system bandwidth is divided
into a plurality of orthogonal.
 Orthogonality of different subcarriers is achieved by the baseband
IFFT.
 Available bandwidth is divided into several subchannels
 Symbols are transmitted on different subcarriers
OFDM
 OFDM has many advantages that can meet the needs of
E-UTRAN, which is one of B3G and 4G key technology.
 OFDM is a modulation multiplexing scheme, and the
corresponding multi-access techniques is OFDMA.
OFDMA are used in LTE downlink.
 For LTE uplink the multiple access scheme is SC-FDMA .
…
Sub-carriersFFT
Time
Symbols
System Bandwidth
Guard
Intervals
…
Frequency
…
Sub-carriersFFT
Time
Symbols
System Bandwidth
Guard
Intervals
…
Frequency

14. Ekstensi TelkomTelekomunikasi Unjani
OFDM & OFDMA
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OFDM
• Semua subcarrier dialokasikan untuk satu user
OFDMA
• Subcarrier dialokasikan secara fleksibel untuk banyak user tergantung pada
kondisi radio.

15. Ekstensi TelkomTelekomunikasi Unjani
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).
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16. Ekstensi TelkomTelekomunikasi Unjani
OFDMA time-frequency multiplexing
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17. Ekstensi TelkomTelekomunikasi Unjani
OFDMA & SC-FDMA
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OFDM & OFDMA
 OFDM (Orthogonal Frequency Division Multiplexing) is a modulation
multiplexing technology, divides the system bandwidth into orthogonal
subcarriers. CP is inserted between the OFDM symbols to avoid the ISI.
 OFDMA is the multi-access technology related with OFDM, is used in the
LTE downlink. OFDMA is the combination of TDMA and FDMA essentially.
 Advantage: High spectrum utilization efficiency due to orthogonal
subcarriers need no protect bandwidth. Support frequency link auto
adaptation and scheduling. Easy to combine with MIMO.
 Disadvantage: Strict requirement of time-frequency domain
synchronization. High PAPR.
DFT-S-OFDM & SC-FDMA
 DFT-S-OFDM (Discrete Fourier Transform Spread OFDM) is the
modulation multiplexing technology used in the LTE uplink,
which is similar with OFDM but can release the UE PA limitation
caused by high PAPR. Each user is assigned part of the system
bandwidth.
 SC-FDMA（Single Carrier Frequency Division Multiple
Accessing）is the multi-access technology related with DFT-S-
OFDM.
 Advantage: High spectrum utilization efficiency due to
orthogonal user bandwidth need no protect bandwidth. Low
PAPR.
 The subcarrier assignment scheme includes Localized mode
and Distributed mode.
User 1
User 2
User 3
Sub-carriers
TTI: 1ms
Frequency
System Bandwidth
Sub-band：12Sub-carriers
Time
User 1
User 2
User 3
User 1
User 2
User 3
Sub-carriers
TTI: 1ms
Frequency
System Bandwidth
Sub-band：12Sub-carriers
Time
Sub-carriers
TTI: 1ms
Frequency
Time
System Bandwidth
Sub-band：12Sub-carriers
User 1
User 2
User 3
Sub-carriers
TTI: 1ms
Frequency
Time
System Bandwidth
Sub-band：12Sub-carriers
User 1
User 2
User 3
User 1
User 2
User 3

18. Ekstensi TelkomTelekomunikasi Unjani
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).
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19. Ekstensi TelkomTelekomunikasi Unjani
Resource Block
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20. Ekstensi TelkomTelekomunikasi Unjani
Adaptive Modulation and Coding
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2 bits per symbol in
each carrier.
4 bits per symbol in
each carrier.
6 bits per symbol in
each carrier.

21. Ekstensi TelkomTelekomunikasi Unjani
MIMO ANTENNA
• MIMO: Multiple input – multiple output
• Given an arbitrary wireless communication system:
”A link for which the transmitting end as well as the receiving end is
equipped with multiple antenna elements”
• The signals on the transmit antennas and receive antennas are ”combined”
to improve the quality of the communication (ber and/or bps)
• MIMO systems use space-time processing techniques
Time dimension is completed with the spatial dimension
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22. Ekstensi TelkomTelekomunikasi Unjani
Multiple antenna fundamentals
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23. Ekstensi TelkomTelekomunikasi Unjani
Throughput Calculation
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24. Ekstensi TelkomTelekomunikasi Unjani
LTE UL/DL Throughput (MAC Layer) Calculation
• DL Throughput (MAC Layer) = (168-36-12)x (Code bits) x (Code rate) x Nrb x C x 1000 - CRC
• UL Throughput (MAC Layer) = (168-12) x (Code bits) x (Code rate) x Nrb x C x 1000 - CRC
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168 = Number of Resource Elemen (RE) in 1 ms.
36 = Number of Control Channel RE in 1 ms.
12 = Number of Refference Signal RE in 1 ms.
CRC = 24 (fixed).
Code Bits = number of bit per symbol, below :
QPSK = 2
16QAM = 4
64QAM = 6
Code Rate= ½, ¾, 5/6, etc.
C = Refers to MIMO configuration
NO MIMO = 1
MIMO 2x2 = 2
Nrb (Number of Resource Block) = Based on Bandwidth, can be seen from table below.
20 Mhz, Nrb = 100
15 Mhz, Nrb = 50

25. Ekstensi TelkomTelekomunikasi Unjani
For Example
• BW = 10 MHz
• Modulation & Coding Scheme = 64QAM5/6
• NO MIMO
DL Throughput (MAC Layer) = (168-36-12) x (Code bits) x (Code rate) x Nrb x C x 1000 – CRC
= (168-36-12) x 6 x 5/6 x 50 x 1 x 1000 – 24
= 29,999976 Mbps = 30 Mbps
• BW = 20 MHz
• Modulation & Coding Scheme = 64QAM5/6
• NO MIMO
DL Throughput (MAC Layer) = (168-36-12) x (Code bits) x (Code rate) x Nrb x C x 1000 – CRC
= (168-36-12) x 6 x 5/6 x 100 x 1 x 1000 – 24
= 59,999976 Mbps = 60 Mbps
• BW = 20 MHz
• Modulation & Coding Scheme = 64QAM5/6
• MIMO 2*2
DL Throughput (MAC Layer) = (168-36-12) x (Code bits) x (Code rate) x Nrb x C x 1000 – CRC
= (168-36-12) x 6 x 5/6 x 100 x 2 x 1000 – 24
= 119,999976 Mbps = 120 Mbps
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26. Ekstensi TelkomTelekomunikasi Unjani
Reference
• LTE Internal Document by Huawei
• LTE Training material 4G RF Planning & Optimization
by Float Way Systems
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