Towards Wireless Multi-Gigabit Systems Towards Wireless Multi - PowerPoint PPT Presentation

Technische Universität Carolo-Wilhelmina zu Braunschweig tubs.CITY Jahrestagung 2009 tubs C Ja estagu g 009 Towards Wireless Multi-Gigabit Systems – Towards Wireless Multi Gigabit Systems Channel Models, Regulation and Standardisation Standardisation Thomas Kürner 02.07.2009

Towards Wireless Multi-Gigabit Systems Content • Terahertz Communications Lab • Motivation • Channel Models for 60 GHz Systems • Propagation conditions beyond 100 GHz P ti diti b d 100 GH - Free space path loss, diffraction, transmission - Reflection and scattering - A simple two ray model A simple two-ray model • Regulation and Standardisation • Challenges and future work Prof. Dr.-Ing. Thomas Kürner 2/37

Terahertz Communications Lab (TCL) TCL consists of five research groups @ Braunschweig Mobile Radio Systems Terahertz Systems VLSI Design Microwave German Institute Engineering of Standards (PTB) http://www.tcl.tu-bs.de Prof. Dr.-Ing. Thomas Kürner 3/37

Source: IEEE Spectrum, Juli 2004 Edholm‘s Law of data rates Prof. Dr.-Ing. Thomas Kürner Motivation 4/37

Motivation What are potential Applications for Multi-Gigabit Radio Systems? • WLANs • WPANs HDD • Point-to-point links, e.g. hard-drive to computer, camera to computer • Wireless extension of Ethernet and GigabitEthernet LANs • Kiosk downloading Prof. Dr.-Ing. Thomas Kürner 5/37

Motivation Frequency Bands for Multigigabit Systems • Commerically available systems - currently data up 100 Mbps @ 2.4, 5.2 GHz - - Several 100 Mbps with IEEE802 11n Several 100 Mbps with IEEE802.11n • Systems currently under development, which have caused significant interest in industry in industry - upcoming 1.3 Gbps @ 3-10 GHz and 3-5 Gbps @ 60 GHz • • Future systems currently considered in research partly with first Future systems currently considered in research, partly with first demonstrators in laboratory - ~10 Gbps @ 122 GHz (NTT Docomo) - Towards 100 Gbps @ THz frequencies (300-400 GHz) Towards 100 Gbps @ THz frequencies (300 400 GHz) Prof. Dr.-Ing. Thomas Kürner 6/37

Channel Modeling at 60 GHz Building a Wireless HDMI at 60 GHz • Beamforming required for seamless service i • Propagation Channel must be well understood in realistic environments understood in realistic environments • Application of measurements and ray- tracing to derive statistical channel tracing to derive statistical channel models Prof. Dr.-Ing. Thomas Kürner 7/37

Channel Modeling at 60 GHz Measurements and Modeling of Angle-of-Arrival and Angle-of-Departure Direct path Tx First Order Reflections Second Order Reflections Rx Prof. Dr.-Ing. Thomas Kürner 8/37

Channel Modeling at 60 GHz Measurement of Signal Variations caused by a Person stepping into the direct Ray Prof. Dr.-Ing. Thomas Kürner 9/37

Channel Modeling at 60 GHz Generating Statistical Models – an Example from Ray- Tracing in an Empty Room Scenario Rx 5 m T x Prof. Dr.-Ing. Thomas Kürner 10/37

Propagation Conditions beyond 100 GHz Free Space Loss and Atmospheric Attenuation 200 180 160 140 120 100 100 50 50 80 900 Distance / m 500 10 100 Frequency /GHz • High gain antennas are required • Atmospheric attenuation can be neglected in indoor environments Prof. Dr.-Ing. Thomas Kürner 11/37

Propagation Conditions beyond 100 GHz 300 GHz Transmission System 4 m 4 m -9 4 dB Prof. Dr.-Ing. Thomas Kürner 12/37

Propagation Conditions beyond 100 GHz 300 GHz Transmission System UHF FBAS-Signal FBAS-Signal UHF 855 ± 6 MHz 855 ± 6 MHz -40 dBm 40 dBm VHS-Rek. DVD-Player TV-Karte d = 10 m G Verstärker = 37,5 dB L M = 9,7 dB G L1 = 14 dB G L2 = 14 dB L M = 9,7 dB L ZF-Misch = 8,3 dB L att = 10 dB G Ant = 26 dB G Ant = 26 dB F Verstärker = 7,1 dB T M = 960 K T M = 980 K T ZF-Misch = 700 K 4.185 ± 6 MHz Mini circuits VDI VDI VDI VDI ANZAC PE Linsen PE-Linsen „ZHL-42W“ ZHL 42W“ „WR2.8SHM“ WR2 8SHM“ Di Diagonalhorn lh Di Diagonalhorn lh „WR2.8SHM“ WR2 8SHM“ „MDC-166“ MDC 166“ (WR2.8) (WR2.8) Jastrow, C., Münter, K., Piesiewicz, R., Kürner, T., Koch, M., Kleine-Ostmann, T., ‘300 GHz transmission system’, IEE Electronics Letters, Vol. 44, No. 3, January 2008, pp. 213-214. Prof. Dr.-Ing. Thomas Kürner 13/37

Propagation Conditions beyond 100 GHz …more details on the mixer a) am plifier DP RO and tripler 16.66 G Hz 150 G Hz W R 6.5x3 ~ x 3 tripler tripler 50  term ination 0… 10 G Hz 290 G Hz… 310 G Hz < 0.5 mW m onitor 50 µW port signal ~ generator generator crystal oscillator b) am plifier DP RO DP RO and tripler and tripler 16.38 G Hz 147.5 G Hz W R 6.5x3 ~ x 3 tripler 50  290 G Hz… 310 G Hz term ination 5… 15 G Hz m onitor m onitor port spec trum ~ analys er crystal oscillator Prof. Dr.-Ing. Thomas Kürner 14/37

Propagation Conditions beyond 100 GHz Transmitter Phasengeregelter DRO (16,67 GHz) Referenzquartz (10 MHz) Verstärker / Verdreifacher (50 GHz) V d if h (50 GH ) Verdreifacher (150 GHz) Oberwellenmischer Oberwellenmischer (300 GHz) Monitorport & Vorverstärker Prof. Dr.-Ing. Thomas Kürner 15/37

Propagation Conditions beyond 100 GHz Received signal without lense antennas 50 cm 10 cm 80 cm 30 cm Prof. Dr.-Ing. Thomas Kürner 16/37

Propagation Conditions beyond 100 GHz Received signal with lense antennas 10 m 21,5 m Reflection on 15 m painted wall (4m) Prof. Dr.-Ing. Thomas Kürner 17/37

Propagation Conditions beyond 100 GHz Transmission, Diffraction and Reflection/Scattering • attenuation is high enough to neglect transmission as a relevant transmission as a relevant propagation mechanism in indoor environments at THz frequencies • diffraction does not constitute a relevant propagation mechanism already at mm-waves • Reflection and scattering is the only relevant mechanism Prof. Dr.-Ing. Thomas Kürner 18/37

Propagation Conditions beyond 100 GHz An experiment using the 300 GHz system Tx Rx Prof. Dr.-Ing. Thomas Kürner 19/37

Propagation Conditions beyond 100 GHz An experiment using the 300 GHz system Prof. Dr.-Ing. Thomas Kürner 20/37

Propagation Conditions beyond 100 GHz Modelling the Indoor Propagation Channel • As at 60 GHz Ray-tracing is well-suited to model the propagation channel beyond 100 GHz in indoor y environments • Proper modelling of reflection and scattering processes for typical building materials required: - Reflection on smooth surface - S Scattering on rough surface i h f - Reflection on multi-layer objects Prof. Dr.-Ing. Thomas Kürner 21/37

Reflection Measurements and Modeling Rough Surface Scattering in Specular Direction Scattering on Rough Surfaces plaster Raufaser wallpaper Prof. Dr.-Ing. Thomas Kürner 22/37

Reflection Measurements and Modeling Rough Surface Scattering in Specular Direction Raufaser, 30 Grad, TE Polarization Raufaser, 70 Grad, TE Polarization Raufaser, 50 Grad, TE Polarization Raufaser, 40 Grad, TE Polarization Raufaser, 60 Grad, TE Polarization Raufaser, 25 Grad, TE Polarization 1 1 1 1 1 1 Raufaser, 70 Grad, TE Polarization 1 1 0.8 0.8 0.8 0.8 0.8 0.8 0.8 aktor aktor aktor aktor aktor aktor tor 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Reflexionsfa Reflexionsfa Reflexionsfa Reflexionsfa Reflexionsfa Reflexionsfa Reflexionsfakt 0.6 Measured Surface Properties of Raufaser 0.4 0.4 0.4 0.4 0.4 0.4 0.4 1 Raufaser R R R R R R R 0.8 elative Häufigkeit 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.6 0.4 0 100 100 150 150 200 200 250 250 300 300 350 350 400 400 450 450 Re f [GHz] 0 0 0 0 0 0 0.2 100 100 100 100 100 100 150 150 150 150 150 150 200 200 200 200 200 200 250 250 250 250 250 250 300 300 300 300 300 300 350 350 350 350 350 350 400 400 400 400 400 400 450 450 450 450 450 450 f [GHz] f [GHz] f [GHz] f [GHz] f [GHz] f [GHz] 0 -0.5 0 0.5 Oberflächenhöhe [mm] Prof. Dr.-Ing. Thomas Kürner 23/37

Reflection Measurements and Modeling Bistatic reflection coefficient for double glass as a function of incidence angle and frequency Prof. Dr.-Ing. Thomas Kürner 24/37

Reflection Measurements and Modeling Multiple Layer Modelling • Calculation of reflection and transmission coefficients by transfer matrix method Magnitude of reflection coefficient: white paint on plaster Prof. Dr.-Ing. Thomas Kürner 25/37

Measurement set-up Two-Ray-Modeling at 300 GHz Prof. Dr.-Ing. Thomas Kürner 26/37

Comparing Measurements with the Model Two-Ray-Modeling at 300 GHz Prof. Dr.-Ing. Thomas Kürner 27/37

System simulations Influence of wall materials Maximum achievable data rates for Smooth plaster (  =0 mm) Plastic mirrors different for wall materials form link level simulation • empty room scenario • assuming all walls are covered by g y the same material • BPSK modulation rough plaster (  =0,05 mm) very rough plaster (  =0,15 mm) • once-reflected paths Prof. Dr.-Ing. Thomas Kürner 28/37