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RISET DAN PERKEMBANGAN TEKNOLOGI WIRELESS ACCESS NETWORKS

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Presentation on theme: "RISET DAN PERKEMBANGAN TEKNOLOGI WIRELESS ACCESS NETWORKS"— Presentation transcript:

1 RISET DAN PERKEMBANGAN TEKNOLOGI WIRELESS ACCESS NETWORKS
Adit Kurniawan PROGRAM STUDI/KK TEKNIK TELEKOMUNIKASI INSTITUT TEKNOLOGI BANDUNG

2 OUTLINES SEMINAR Introduction
Perkembangan dan evolusi teknologi wireless access networks Enabling technologies Riset wireless access network Penutup dan diskusi/tanya jawab

3 INTRODUCTION TOPIK SEMINAR

4 EVOLUSI DAN PERKEMBANGAN TEKNOLOGI WIRELESS TELECOMMUNICATION

5 Evolusi standard/teknologi askses
EDGE WCDMA FDD HSDPA/ HSUPA GSM HSCSD GPRS LTE HSDPA/ HSUPA TD-CDMA TDD HCR TD-SCDMA TDD LCR cdma2000 1XEV - DO cdmaOne (IS-95) cdma2000 cdma2000 1XEV - DV

6 Mobilitas v/s Data rates

7 WiMAX – EKSPANSI COVERAGE
World Interoperability for Microwave Access There are two main applications of WiMAX: Fixed WiMAX (IEEE ) - Fixed WiMAX applications are point-to-multipoint enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL for homes and businesses. Mobile WiMAX (IEEE e-2005) - Mobile WiMAX offers the full mobility of cellular networks at true broadband speeds.

8 FIXED - WiMAX Fixed WiMAX Architecture

9 FIXED - WiMAX Mobile WiMAX Architecture

10 LTE – EKSPANSI DATA RATE
LTE is the latest standard in the mobile network technology tree that previously realized the GSM/EDGE and UMTS/HSxPA network Characteristics : Significantly increase peak data rates, scaled linearly according to spectrum allocation improving spectral efficiency lowering costs improving services making use of new spectrum opportunities Improved quality of service better integration with other open standards LTE is the next step on a clearly-charted roadmap to so-called ‘4G’ mobile systems that starts with today’s 2G and 3G networks. Building on the technical foundations of the 3GPP family of cellular systems that embraces GSM, GPRS and EDGE as well as WCDMA and now HSPA (High Speed Packet Access), LTE offers a smooth evolutionary path to higher speeds and lower latency. Coupled with more efficient use of operators’ finite spectrum assets, LTE enables an even richer, more compelling mobile service environment.

11 LTE Network Architecture
The LTE architecture consists of E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) on the access side and EPC (Evolved Packet Core) on the core side. A typical LTE/SAE network will have two types of network elements. The first is the new enhanced base station, so called “Evolved NodeB (eNodeB)” per 3GPP standards. This enhanced BTS provides the LTE air interface and performs radio resource management for the evolved access system. The second is the new Access Gateway (AGW). The AGW provides termination of the LTE bearer. It also acts as a mobility anchor point for the user plane. It implements key logical functions including MME (Mobility Management Entity) for the Control Plane and for the User Plane. These functions may be split into separate physical nodes, depending on the vendor-specific implementation.

12 Wireless Mobile Broadband

13 Mobile Broadband Infrastructure

14

15 INTELLIGENT TRANSPORT SYSTEM (ITS)

16 High Altitude Stratospheric Platform Services (HAPS)
Menambah Coverage dan Capacity

17 ENABLING TECHNOLOGIES

18 PROBLEMS OF WIRELESS CHANNEL
Incoming signal consists of several paths with different time delays (multiple copies of the same signal) Signal Fluctuation leads to loss of SNR Intersymbol Interference leads to very slow data rate

19 FREQ. SPECTRUM LIMITATION

20 FDM vs. OFDM Conventional v/s Modern FDM technique

21 LTE-Downlink (OFDM) Improved spectral efficiency
Reduce ISI effect by multipath Against frequency selective fading frequency selective fading 在正交分頻多工系統中,原來的寬頻通道被分割成N 個子通道,透過使用串列至並行轉換器,將資料送至各個子載波上,由於資料區間被拉長為原本的N倍, 所以這些子載波有著較低的傳輸速率,當子通道數目足夠多時,每個子載波可以視具有平坦的通道頻率響應,進而可以有效的對抗頻率選擇性衰減通道所造成的失真

22 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

23 Multi-antenna techniques

24 Phased Array Antenna... Beam-steering using phase shifters at each radiating element Beam direction 3 2 d Equi-phase wave front  = [(2/)d sin] Radiating elements Phase shifters Power distribution

25 MIMO techniques<=> different propagation environment
WLL MSC LOS Urban area BS BS NLOS Rural area BS MSC multiple antennas at MS

26 SDMA concept - expected up to 8 times capacity improvement
- power classes concept (can be dynamic or static) - with ref. signal BF MSs can be separated even when they have the same angular position to BS ! - for DoABF MSs angular distribution is important (macrocell) - network planning (frequency) is simpler, but larger cell size can require new planning, more smooth migration into existing network - more network management upgrade required PCH 1 PCH 1 PCH 1 PCH 1

27 RESEARCH WIRELESS ACCESS NETWORKS

28 Comparison of FDMA, TDMA, and CDMA
                                         FDMA CDMA TDMA Power Frequency Time Code

29 DS-CDMA Concepts– Freq domain
Signal-to-interference ratio (SIR) Desired SIR will limit the capacity Wrong code will not detect signal Non CDMA signal received at the Rx will be reduced by spreading and filtering  jammer suppression User’s code Other non-CDMA user

30 CDMA Rake Receiver GSM use equalizer at bit level processing
                                         r(t -1) c(t - ) Despreader Demodulator/Detector D1 D2 D3 r(t -2 r(t -3) Multipath fading is unavoidable in wireless communications CDMA is wideband  Frequency Selective channel Intersymbol Interference (ISI) can be better resolved GSM use equalizer at bit level processing CDMA Rake  chip level processing The number of resolvable paths is much higher. Better performance !!

31 Problem of Power Control - CDMA
The main problems of cellular is multipath propagation : Frequency selective channel due to delay spread propagation. Signal fluctuation due to mobility CDMA is a spread spectrum multiple access technique that uses large bandwidth (1.25 MHz for narrowband and 5 MHz for wideband CDMA). Coherence Bandwidth for typical multipath channel is in the order of hundreeds KHz  CDMA channelis always frequency selective. Need to solve for both problems. (b) Multipath fading problem 2 Pt1 Pr1 Pr2 Pt2 d1 d2 Signal fluctuation User (a) Near-far distance problem Delay spread

32 Multi Carrier Technique (to solve for frequency selective channel)
Carrier bandwidth Bu is divided into J subcarriers of bandwidth Bd so that Bd = Bu/J or Bu = JBd By Choosing a large number of J, bandwidth of each sub carrier can be made lower than the channel coherence bandwidth to produce a frequency non selective channel .

33 Multiuser Detection Receiver
Conventional receiver detects the signal using each user’s code individually. Multiuser detection /receiver (MUD) use all user’s signal to detect each user signal iteratively. In MUD, MAI is reduced for each iteration r(t -) c(t - ) Despreader Demodulator Interference component will decrease by iteration Other user interference is subtracted using feedback

34 Performance Of multi user Detection
Single User Detection Multi User Detection MULTI USER DETECTION IMPROVES DETECTION PERFORMANCE SIGNIFICANTLY

35 Penutup/Diskusi Teknik Multi-Carrier merupakan trend teknologi wireless access network yang bisa mengatasi Problem Kanal Wirelss dan Keterbatasan Frequensi Teknik Multi User Detection bisa menghilangkan/mengurangi interferensi, sehingga meningkatkan kapasitas. Kapasitas dan laju data Wireless Communication meningkat tajam dalam 10 tahun terakhir.


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