WiMAX Experiences and Visions

Transcription

1 WiMAX Experiences and Visions Dr. Wolfgang Wendler 1

2 Introduction to the Market 2

3 Mobility Wireless Landscape Fixed Walk Vehicle GSM GPRS DECT ZigBee RFID / NFC Datarates EDGE 0.1 3G/UMTS Bluetooth Systems Beyond 3G CDMA2000 1xEV-DO e-2005 HSPA b/a/g n UWB Mobility Mbps Datarate 3

4 Applications WLL, FWA, Last Mile, Internet at Home ( ) Backhaul for WiMAX / WLAN Access Points, Microwave Link ( ) BWA, Mobile Internet, mobile Data services (802.16e-2005) WiMAX is technically a 4G System 4

5 WiMAX Shipments vs. WLAN WLAN 250 Shipments WLAN and WiMAX WiMAX Shipments in mio WLAN WiMAX WiMAX 16e Year 0 5

6 WiMAX Overview 6

7 IEEE standards for BRAN* IEEE (WiFi) Short-range: ~100 m Wireless Local Area Networks (WLAN) Referred to as Wi-Fi for Wi-Fi Alliance private character, no network operator necessary (No Handover, No QoS, PtP) IEEE WIMAX Worldwide Interoperability of Microwave Access Long-range: ~3-50 km Wireless Metropolitan Area Networks (WMAN) Korean (Samsung) approach: WiBro for Wireless Broadband public character, i.e. network operator involved (Handover, QoS, PMP) *Broadband Radio Access Network PMP = Point to Multipoint PtP = Point to Point 7

8 Data Rate [MBit/s] IEEE BRAN Standards b SC 2,4 GHz, 11 MBit/s no mobility a OFDM (64 carrier) 5 GHz 54 MBit/s no mobility OFDM (256 carrier) 136 MBit/s no mobility g / h SC & OFDM (64+ carrier) 2,4 GHz 108 MBit/s no mobility OFDMA (2048 carrier) 100 MBit/s no mobility e OFDMA ( carrier) 2 6 GHz 15 MBit/s mobile n OFDM 5 GHz, 600 MBit/s MIMO 09/ / / / / / /2006 Evolution over time 8

9 The WiMAX IEEE Evolution 9

10 Non-IEEE BRAN approaches ETSI (European Telecom Standards Institute) Over 50 liaisons between and ETSI ETSI HIPERMAN Below 11 GHz IEEE began first (802.16a) Harmonized with OFDM Cooperation on conformance tests Korea: WIBro (Wireless Broadband) Several liaisons with TTA (Telecommunication Technology Association) WiBro must comply with IEEE and IEEE e-2005 or later versions. 10

11 Conformance Specifications IEEE /Conf01 >10 GHz PICS Aug /Conf02 > 10 GHz TSS&TP Feb 04 Rohde & Schwarz /Conf03 > 10 GHz RCT Jun 04 has been selected as WiMAX RCT vendor by Conformance Specifications IEEE e-2005 P802.16/Conf04 <11 GHz PICS Start May 04 the WiMAX Forum PICT = Product Implementation Conformance Statement TSS&TP = Test Suite Structure & Test Purpose RCT = Radio Conformance Test 11

12 The fixed WiMAX IEEE OFDM (WirelessMAN-OFDM) 256-point FFT (ETSI HiperMAN) OFDMA (WirelessMAN-OFDMA) 2048-point FFT Single-Carrier (WirelessMAN-SCa) NLOS application More efficient IP and small packet transport Support for more users per channel Flexible QoS ARQ for link reliability Adaptive Antenna System (AAS) support Dynamic Frequency Selection (DFS) for unlicensed bands Support of Mesh Operation PHY MAC 12

13 mobile WiMAX IEEE e-2005 amendments Kept the Fixed PHYs but added Scalable OFDMA 128, 512, 1024 and 2048 FFT Automatic FFT size / bandwidth detection by SS Expanded MIMO Support PHY H-ARQ (Hybrid Automatic Repeat Request) Handover Support Make-Before-Break, Break-Before-Make Macro-Diversity Handover Sleep Mode Scanning for neighbors Advertisement of neighborhood (Broadcasting of the neighbor cells) Efficient network re-entry process MAC 13

14 WIMAX Operation Frequency Bands MDS (Multipoint Distribution System) GHz WCS (Wireless Communication Service) and GHz (BW = MHz, F s = MHz) MMDS (Multichannel Multipoint Distribution Service) GHz (BW = MHz, F s = MHz) ETSI (European Telecommunications Standards Institute) and GHz (BW = MHz, F s = 2 32 MHz) U-NII (Unlicensed National Information Infrastructure) and GHz (BW MHz, F s = MHz) 14

15 3G to 4G capabilities Rates per cell Rates per subscriber Latency Deployment expected Application 3G 10 Mbps (5 MHz BW) 0.5 Mbps > 100 ms 2006 Basic Multimedia 16e 75 Mbps (20 MHz BW) 5-10 Mbps < 100 ms 2007 Broadband Multimedia quadruple play LTE 100 Mbps (20 MHz BW) 10 Mbps 10 ms 2008 Broadband Multimedia quadruple play 4G 1 Gbps (100 MHz BW) 100 Mbps < 10 ms 2012 Full broadband High quality Multimedia Quadruple play = Telephony, Internet, Video, Mobility LTE = Long Term Evolution = E-UTRAN (in LTE 3GPP moves to OFDM) Latency = Round Trip Time (Time from a Request for a Package to RNC to received Package) 15

16 Physical Layer in Detail 16

17 OFDM Why Orthogonal Frequency Division Multiplexing? Problem of multi-path interference with one carrier: Transmitter Signal Receiver Signal t Delay Delay spread t Multi-path interference when symbol duration shorter than delay spread 17

18 OFDM Inter-symbol interference Multipath interference in a high rate single-carrier system No of paths C 2 interferes with C 0, C 1 and with itself delay delay Symbol C 0 Symbol C 1 Symbol C 2 Symbol C 0 Symbol C 1 Symbol C 2 Symbol C 0 Symbol C 1 Symbol C 2 time Symbol time T s Delay in the different paths causes interference 18

19 OFDM Solution to this problem of inter-symbol interference Single Carrier Symbol C 0 Symbol C 1 Symbol C 2 Symbol time T s t f 2 Symbol C 2 Multi Carrier f 1 Symbol C 1 f 0 Symbol C 0 Symbol time T S t Due to the longer transmission time T S multi-path interference is reduced 19

20 OFDM Principle of orthogonality of frequency f 2 f 1 duration T S 1/T S f 0 f 2 Characteristics of orthogonal waveforms: f Carrier = f 0 +n/t S where n is an integer f 0 f 1 f The maximum of one carrier is at the zero crossings of all others The cross correlation of sine waves is zero, if they are sampled at the correct location This is obtained by the following setting Δf = 1/T S, therefore: f n = n x Δf 20

21 OFDM Suppressing multipath interference Receiver Symbol 1 Symbol 2 Delay spread time Problem: Due to different paths to the receiver, the different OFDM symbols would interfere with themselves or each other 21

22 OFDM Suppressing multipath interference Guard intervall of 4 µs By inserting a guard period (cyclic extension) the multi-path interference can be reduced 16 µs Receiver intervall 16 µs Guard intervall Region where only self-interference occurs Region of ISI 22

23 WiMAX OFDM and WLAN a/g OFDM Parameter WiMAX WLAN FFT length Number of carriers used Number of pilot carriers 8 4 Duplex FDD/TDD TDD Bandwidth Scalable from 1.25 MHz up to 28 MHz Fixed 20 MHz Turbo mode 40 MHz 23

24 WiMAX OFDM and WLAN a/g OFDM Parameter WiMAX WLAN Modulation formats BPSK, QPSK, 16QAM, 64QAM BPSK, QPSK, 16QAM, 64QAM Guard period ¼, 1/8, 1/16, 1/32 Fixed MiMo Adaptive antenna systems Sub channalization Yes Yes No scheduled for n No 24

25 Rev. d: OFDM Mode OFDM parameter: FFT Size: 256 Used Carriers: 200 Pilots: 8 Guard Carriers: 28 left, 27 right Channel BW: MHz 25

26 Frame Structure of WiMAX OFDM Frame n Frame n+1 Frame m DL sub frame UL Subframe Preamble FCH DL burst #1 DL burst #n Preamble UL burst 2 Symbols 1 Symbol Preamble definition Every fourth subcarrier Even numbered subcarriers 50 active QPSK carriers 100 active QPSK carriers Short Preamble Long Preamble 26

27 WiMAX OFDMA Parameter: FFT Size: 2048 Used Carriers: variable Pilots: diff. sets (const. + variable) ~ 192 Guard Carriers: variable left, right Channel BW: MHz 27

28 WiMAX OFDMA 28

29 MIMO Standardisation in WiMAX e-2005 WirelessMAN-SC WirelessMAN-SCa WirelessMAN-SCa Wireless-MAN-OFDM Wireless-MAN-OFDM MISO Wireless-MAN-OFDMA MIMO Wireless-MAN-OFDMA MIMO Wireless-HUMAN 29

30 What is MIMO? SISO MISO Nx1 SIMO 1xM Single/Multiple Input Transmitter Single/Multiple Output Receiver 1 N 30 1 M MIMO NxM

31 Beamforming 31

32 Fading E A D C A: free space B: reflection C: diffraction D: scattering E: shadowing (birth death) F: doppler Transmitter B Receiver F reflection: object is large compared to wavelength scattering: object is small or its surface irregular 32

33 Solutions of Rohde & Schwarz 33

34 Signal Generation The SMx Family of Vector Signal Generators: SMU 200A SMJ 100A SMATE 200A covered by by IEEE Rev. d OFDM/OFDMA IEEE e-2005 OFDM/OFDMA Option K49 34

35 SMU200A - Configuration SMU200A Vector Signal Generator SMU-B SMU-B SMU-B SMU-B khz to 2.2 GHz 100 khz to 3 GHz 100 khz to 4 GHz 100 khz to 6 GHz SMU-B x Baseband Gen. with ARB (64 MSamples) and Digital Mod. SMU-B Baseband Main Module SMU-K Digital Standard IEEE x SMU-B x Baseband Gen. with ARB (16 MSamples) and Digital Mod. 2x SMU-B Fading Simulator SMU-K Dynamic Fading and Enhanced Resolution SMU-B Fading Simulator Extension SMU-K Dynamic Fading and Enhanced Resolution 35

36 OFDM Receiver Tests Receiver sensitivity Receiver adjacent and alternate channel rejection Receiver maximum input signal Receiver maximum tolerable signal Receiver image rejection Frequency and Timing 36

37 WiMAX in the SMU Family Configuration Panel (FDD, DL) predefined test messages 37

38 OFDM - Frame Configuration 38

39 Setting OFDM or OFDMA 39

40 OFDMA Frame Configuration 40

41 PUSC and FUSC FUSC = Fully Utilized Subchannel Allocation all subchannels are used for transmission PUSC = Partially Utilized Subchannel Allocation only a part of the subchannels are used for transmission 41

42 Automatic UL Map generation For generating the Downlink signal you need to know the Uplink map 42

43 Convolution Turbo Coding CTC: error correction coding, just like CC 43

44 Space time coding Path A Transmit Dicersity Path B first Mimo application 44

45 Fading with R&S SMU200A 45

46 Fading Concept Modern Baseband Fader Example SMU200A digital analog RF Low price Broad frequency band No conversion loss (pure digital 18 bit) Small size (one box solution, even for dual channel fading) 46

47 Fading for WiMAX Besides others GSM and 3GPP scenarios are available. 47

48 OFDM Transmitter Tests Channel quality measurements (e.g. CINR) Transmit power level Transmitter spectral flatness Transmitter constellation error Transmitter channel bandwidth and RF carrier frequency Frequency and Timing 48

49 Signal Analysis of WIMAX Signals covered by byvsa IEEE , WirelessMAN-SC PHY FSQ-K70 covered by by FSQ-K92 IEEE WirelessMAN-OFDM PHY covered by by FSQ-K93 IEEE , e-2005 WirelessMAN-OFDMA PHY 49

50 Signal Analysis FSQ-K92/K93 Settings 50

51 Application Firmware FSQ-K92/K93 Scalar Results: EVM Measurements EVM all Carriers EVM Data Carriers only EVM Pilot Carriers IQ constellation IQ Offset Gain Imbalance Quadrature Offset Power Measurement Power Burst Crest Factor Symbol Clock Error CINR Measurement 51

52 Scalar Results 52

53 Application Firmware FSQ-K92/K93 Graphical Results: EVM Measurements EVM vs. Symbol EVM vs. Carrier Phase/Frequency Error vs. Preamble Spectrum Flatness (Difference) Group Delay Constellation Diagram Bit Stream Spectrum Emission Mask (IEEE,ETSI) Adjacent Channel Power (absolute and relative) CCDF measurement 53

54 Graphical Results EVM versus Symbol Peak Average Minimum 54

55 Spectrum Flatness and Spectrum Flatness Difference Frequency FrequencyError vs. vs. Preamble Preamble Uplink Downlink 55

56 All Mode All bursts of a frame can be analysed the results for EVM and power are displayed in a table and a composite constellation diagram can be displayed 56

57 Demodulation Settings for OFDMA Signal - Number of Zones - Number of Zones -Type -Type - Offset and length - Offset and length Used Used subchannel subchannel group group Downlink Downlink - - Number Number of of Bursts Bursts - - Allocation Allocation - - Modulation Modulation Graphic Graphic of of Channel Channel Map Map Used Used subchannel subchannel group group Uplink Uplink R&S SMU Settings can be imported 57

58 Demodulation Settings for OFDMA Signal Used Used subchannel subchannel group group Downlink Downlink Used Used subchannel subchannel group group Uplink Uplink 58

59 EVM v s. Carrier (PUSC zone) 59

60 Roadmap 60

61 Generator Solutions Roadmap AMC Sounding HARQ & Fast Feedback Channels WiMAX SUI Fading Models SMU, SMJ, SMATE RF Generators With WiMAX Option K4 WinIQSim2 Simulation Software

62 Analyzer Solutions Roadmap -K93 DL- and UL- AMC Channel decoding DL- OFUSC and UL- OPUSC Dedicated pilots FSL-K93 internal solution FSQ-K93 Group delay measurement Decode and display FCH field Auto demodulation according to DL- and UL- map DL- and UL- PUSC using all subchannels Amplitude tracking (DL- and UL- AMC) OFDMA FSQ-K93 solution internal Analysis of 1 out of N zones Analysis 1 of 3 segments Transfer SMU settings to FSQ via LAN Measurement of TTG, RTG FSQ and FSL Signal Analysis With WiMAX OFDM Option -K92 (internal) With WiMAX OFDMA Option -K93 (external) -K93 includes -K

63 R&S WiMAX RCT Test System R&S SMU Signal Generation R&S SMU WiMAX BSSE R&S Controller R&S Power Sensor BB Fading/ Interferer R&S RF SSCU R&S FSQ Signal Analysis 63

64 Other Rohde & Schwarz T&M solutions Rohde & Schwarz delivers also other T&M solutions, which can be helpful for your WiMAX development and production testing like: Power Meters Spectrum Analysis FSH 3/6 Arbitrary Waveform Generator AFQ100A Have a look under 64