Presentation on theme: "Introduction to Ultra WideBand Systems"— Presentation transcript:
1 Introduction to Ultra WideBand Systems Chia-Hsin Cheng
2 Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signalsUWB in IEEE 802 StandardsThe Application of UWB
3 IntroductionThe world of ultra wideband (UWB) has changed dramatically in very recent history. In the past 20 years, UWB was used for radar, sensing, military communications and niche applications.A substantial change occurred in February 2002, when the FCC (2002a,b) issued a ruling that UWB could be used for data communications as well as for radar and safety applications.Recently, UWB technology has been focused on consumer electronics and communications.Ideal targets for UWB systems are low power, low cost, high data rates, precise positioning capability and extremely low interference.
4 UWB Transmitter Defined UWB transmitter signal BW:Or, BW ³ 500 MHz regardless of fractional BWfu-fl2³ 0.20fu+flWhere:fu= upper 10 dB down pointfl = lower 10 dB down pointSource: US 47 CFR Part15 Ultra-Wideband Operations FCC Report and Order, 22 April 2002:
5 UWB: Large Fractional Bandwidth CDMA: 1.288Mcps/1.8 GHz0.07% bandwidthone “chip”UWBNB6% bandwidth20% bandwidthPower Spectral Density (dB)-80-40Frequency (GHz)3691215Random noise signal100% bandwidth
6 Large Relative (and Absolute) Bandwidth Narrowband (30kHz)Part 15 Limit( -41.3dBm/Hz )Wideband CDMA (5 MHz)UWB (Several GHz)FrequencyUWB is a form of extremely wide spread spectrum where RF energy is spread over gigahertz of spectrumWider than any narrowband system by orders of magnitudePower seen by a narrowband system is a fraction of the totalUWB signals can be designed to look like imperceptible random noise to conventional radios
7 Why is Ultra Wideband So Effective? Shannon showed that the system capacity, C, of a channel perturbed by AWGN ---Where:C = Max Channel Capacity (bits/sec)B = Channel Bandwidth (Hz)S = Signal Power (watts)N = Noise Power (watts)Capacity per channel (bps) µ BCapacity per channel (bps) µ log(1+S/N)Increase BIncrease S/N, use higher order modulationIncrease number of channels using spatial separation(e.g., MIMO)
8 Throughput Low Power UWB Comparable to High Power Wireless Systems UWB throughput between a and b
9 UWB Properties Extremely difficult to detect by unintended users Highly SecuredNon-interfering to other communication systemsIt appears like noise for other systemsBoth Line of Sight and non-Line of Sight operationCan pass through walls and doorsHigh multipath immunityCommon architecture for communications, radar & positioning (software re-definable)Low cost, low power, nearly all-digital and single chip architecture
10 Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signalsUWB in IEEE 802 StandardsThe Application of UWB
11 The history of UWB Technology Before 1900: Wireless Began as UWBLarge RF bandwidths, but did not take advantage of large spreading gains: Wireless goes ‘tuned’Analog processing: filters, resonators‘Separation of services by wavelength’Era of wireless telephony begins: AM / SSB / FMCommercial broadcasting matures, radar and signal processings: Digital techniques applied to UWBWide band impulse radarAllows for realization of the HUGE available spreading gainNow: UWB approved by FCC for commercializationFor further details, refer to ref.
12 What UWB is Today 7,500 MHz available spectrum for unlicensed use US operating frequency: 3,100 – 10,600 MHzEmission limit: -41.3dBm/MHz EIRPIndoor and handheld systemsOther restrictions and measurement procedures in Report and OrderUWB transmitter defined as having the lesser ofFractional bandwidth greater than 20%Occupies more than 500 MHzUWB is NOT defined in terms ofModulationor Carrierlessor Impulse radio
13 Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signalsUWB in IEEE 802 StandardsThe Application of UWB
14 Summary of the FCC Rules Significant protection provided for sensitive systemsGPS, Federal aviation systems, etc.Lowest emission limits ever by FCCIncorporates NTIA (National Telecomm. and Info. Administration) recommendationsAllows UWB technology to coexist with existing radio services without causing interferenceFCC opened up new spectrum for UWB transmissionsOne of the bands is from 3.1GHz to 10.6GHzMaximum power emission limit is dBm/MHz
15 FCC UWB Device Classifications Report and Order authorizes 5 classes of devices with different limits for each:Imaging SystemsGround penetrating radars, wall imaging, medical imagingThru-wall Imaging & Surveillance SystemsCommunication and Measurement SystemsIndoor SystemsHand-held SystemsVehicular Radar Systemscollision avoidance, improved airbag activation, suspension systems, etc.
16 FCC First Report and Order Authorizes Five Types of Devices Class / ApplicationFrequency Band for Operation at Part 15 LimitsUser LimitationsCommunications and Measurement Systems3.1 to 10.6 GHz(different “out-of-band” emission limits for indoor and hand-held devices)NoImaging: Ground Penetrating Radar, Wall, Medical Imaging<960 MHz or 3.1 to 10.6 GHzYesImaging: Through-wall<960 MHz or 1.99 to 10.6 GHzImaging: Surveillance1.99 to 10.6 GHzVehicular22 to 29 GHz
17 UWB Emission Limits for GPRs, Wall Imaging, & Medical Imaging Systems 0.961.611.993.110.6GPS BandOperation is limited to law enforcement, fire and rescue organizations, scientific research institutions, commercial mining companies, and construction companies.Source:
18 UWB Emission Limits for Thru-wall Imaging & Surveillance Systems 0.961.611.9910.6GPS BandOperation is limited to law enforcement, fire and rescue organizations.Surveillance systems may also be operated by public utilities and industrial entities.Source:
19 UWB Emission Limit for Indoor Systems 0.961.611.993.110.6GPS BandSource:
20 Proposed UWB Emission Limit for “Outdoor” Systems 0.961.611.993.110.6GPS BandProposed in preliminary Report and Order,Feb. 14, 2002.Source:
21 Actual UWB Emission Limit for Hand-held Systems 0.010.1110100-80-70-60-50Frequency, GHz-40EIRP, dBm/MHzUWB Band-width must be contained hereFirst Report and Order, April 22, 2002.
22 Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signalsUWB in IEEE 802 StandardsThe Application of UWB
23 UWB Signals Monocycle Shapes for UWB Data Modulation Modulation Schemes
24 Monocycle Shapes for UWB Monocycle shapes will affect the performanceListed monocycles’ duration is 0.5nsGaussian pulseGaussian MonocycleScholtz’s MonocycleManchester MonocycleRZ- Manchester MonocycleSine MonocycleRectangle MonocycleFor further details, refer to ref.
25 Monocycle Shapes for UWB (cont.) Gaussian Pulse
26 Monocycle Shapes for UWB (cont.) Gaussian monocycleSimilar to the first derivative of Gaussian pulse
27 Monocycle Shapes for UWB (cont.) Scholtz’s monocycleSimilar to the second derivative of Gaussian pulse
28 Monocycle Shapes for UWB (cont.) Manchester MonocycleIt has amplitude A during half of the monocycle width and has amplitude –A during the other half.
29 Monocycle Shapes for UWB (cont.) RZ- Manchester MonocycleIt has amplitude A and –A only a portion of each half monocycle width.
30 Monocycle Shapes for UWB (cont.) Sine MonocycleJust a period of sine wave
31 Monocycle Shapes for UWB (cont.) Rectangle MonocycleIt has uniform amplitude A during the whole pulse width.
32 Data ModulationA number of modulation schemes may be used with UWB systems. The potential modulation schemes include both orthogonal and antipodal schemes.Pulse Position Modulation (PPM)Pulse Amplitude Modulation (PAM)On-Off Keying (OOK)Bi-Phase Modulation (BPSK)
33 Modulation SchemesMany different pulse generation techniques may be used to satisfy the requirements of an UWB signal.The FCC requires that the fractional bandwidth is greater than 20 %, or that the bandwidth of the transmitted signal is more than 500MHz, whichever is less.The most common UWB conceptsTime-hopping (TH) techniqueDirect-Sequence (DS) techniqueMulti-band (MB) technique
34 TH-UWB TH-PPM Str(t) Tc t Tf Ts : data symbol time 1. transmitting 0 pulse wtr(t)Str(t)TctTfTs : data symbol time
40 IEEE 802 Organization LAN/MAN Standards Committee (Wireless Areas) WLAN™IEEEWPAN™IEEEWMAN™IEEEMBWAIEEERegulatory TAGIEEECoexistence TAGIEEE“Bluetooth”“High Data Rate” MAC & 2.4 GHz PHYTask Group 3aAlt PHY (UWB)Coexistence“Zigbee” 2.4 GHzStudy Group 4a(UWB?)Mini-Glossary: WLAN-wireless Local Area Network; MAN-Metropolitan Area Network; TAG-Technical Advisory Group;-MBWA-Mobile Broadband Wireless AccessBased on: “Overview of and 3a,” R. F. Heile, Workshop on Current Developments in UWB, Institute for Infocomm Research, Singapore
41 IEEE Project 802 Local and Metropolitan Area Network Standards Committee Accredited by ANSI, Sponsored by IEEE Computer SocietyEthernet, Token Ring, Wireless, Cable Modem StandardsBridging, VLAN, Security StandardsMeets three times per year ( individuals, 15% non-US)Develops equivalent IEC/ISO JTC 1 standardsJTC 1 series of equivalent standards are ISO 8802-nnnIEEE URLs802
44 802.15.3a – high data rate WPAN standard Direct sequence (DS-UWB)Championed by Motorola/XtremeSpectrumClassic UWB, simple pulses,2 frequency bands: GHz, GHzCDMA has been proposed at the encoding layerSpectrum dependent on the shaping filter – possible differing devices worldwideMultiband Orthogonal Frequency Division Multiplexing (MB-OFDM)Intel/TI/many othersSimilar in nature to a/gMHz bands (simplest devices need to support 3 lowest bands, 3.1GHz – 4.7 GHz)Spectrum shaping flexibility for international use
45 Detail of DS-CDMA Candidate for 802.15.3a Multi-band DS-CDMA Physical Layer ProposalSummary from IEEE document a-Merger-2-CFP-Presentation.ppt
46 3 Spectral Modes of Operation Two BandDS-CDMALow BandHigh Band3456789101134567891011Low Band (3.1 to 5.15 GHz)25 Mbps to 450 MbpsHigh Band (5.825 to 10.6 GHz)25 Mbps to 900 MbpsMulti-Band3 Spectral Modes of OperationWith an appropriate diplexer, the multi-band mode will support full-duplex operation (RX in one band while TX in the other)34567891011Multi-Band (3.1 to 5.15 GHz plus GHz to 10.6 GHz)Up to 1.35 Gbps
47 Joint Time Frequency Wavelet Family ExampleDuplex WaveletMidWaveletLong Wavelet34567891011-40-35-30-25-20-15-10-5GHzdB-11-0.50.5
48 Spectral Flexibility and Scalability PHY Proposal accommodates alternate spectral allocationsCenter frequency and bandwidth are adjustableSupports future spectral allocationsMaintains UWB advantages (i.e. wide bandwidth for multipath resolution)No changes to siliconExample 2: Support for hypothetical “above 6 GHz” UWB definitionExample 1: Modified Low Band to include protection for GHz WLAN Band34567891011Note 1: Reference doc IEEE /21134563456
49 Detail of OFDM Candidate for 802.15.3a Multi-band OFDM Physical Layer ProposalSummary from IEEE document 03267r1P802-15_TG3a-Multi-band-OFDM-CFP-Presentation.ppt
50 Overview of Multi-band OFDM Basic idea: divide spectrum into several 528 MHz bands.Information is transmitted using OFDM modulation on each band.OFDM carriers are efficiently generated using an 128-point IFFT/FFT.Internal precision is reduced by limiting the constellation size to QPSK.Information bits are interleaved across all bands to exploit frequency diversity and provide robustness against multi-path and interference.60.6 ns cyclic prefix provides robustness against multi-path even in the worst channel environments.9.5 ns guard interval provides sufficient time for switching between bands.
51 Multi-band OFDM: TX Architecture Block diagram of an example TX architecture:Architecture is similar to that of a conventional and proven OFDM system. Can leverage existing OFDM solutions for the development of the Multi-band OFDM physical layer.For a given superframe, the time-frequency code is specified in the beacon by the PNC (PicoNet Controller). The time-frequency code is changed from one superframe to another in order to randomize multi-piconet interference.
52 Band Plan Group the 528 MHz bands into 4 distinct groups Group A: Intended for 1st generation devices (3.1 – 4.9 GHz)Group B: Reserved for future use (4.9 – 6.0 GHz)Group C: Intended for devices with improved SOP performance (6.0 – 8.1 GHz)Group D: Reserved for future use (8.1 – 10.6 GHz)
53 802.15.4a – alternate PHY for 802.15.4 Addresses the following Globally deployableCompatible / interoperable withLonger rangeHigher reliabilityRanging/localization supportLower latency & support for mobilityLow costCurrent UWB systems not quite suitable90 nm CMOS is expensive, 200 mW is a lot of powerStill in early stagesProposals due Jan. 2005!DS-UWB a major contender (Motorola)Chirp Spread Spectrum another cool tech (Nanotron)Many axes for diversity: Basic tech (2.4 v. UWB), ranging (UWB v. CSS v. Phase-based ranging), pulse shapes, channel arbitration (CSMA v. CDMA)
54 Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signalsStandards of IEEE 802The Application of UWB
55 The Application of UWBUltra-wideband is the contortionist of the wireless world – it is flexible enough to work in many different ways while still maintaining its character.These applications are distributed amongst three categories:Communications and sensorsPosition location and trackingRadar
56 The Application of UWB Source: doc.: IEEE 802.15-01/036r0 Single and multi-family dwelling residents who have at least one of the following configurations in their dwellings:Remote control for:Multimedia PC with interactive gaming optionsConsumer devices like,TV (w internet access), Home Theatre, video gaming console, DVD player, STB, DVCR, Home Stereo, TiVoInterconnectivity between devices (Tomoguchis, Gameboys, etc.)Home security, home automation or HVAC systems (sensors, control units)Illumination control (light switches, spot light control)Small Office/Home Office (SOHO) control of:multimedia presentationsconference roomstraining roomsautomation or control functionsIndustry applications for control and surveillanceHealthcare industry for monitoring and wearable sensors, patient monitoringSource: doc.: IEEE /036r0
57 Source: Walter Hirt, Dennis L Source: Walter Hirt, Dennis L. Moeller, "The Global View of a Wireless System Integrator," International Symposium on Advanced Radio Technologies (ISART), Boulder, CO, USA, 4-6 March 2002
61 Entertainment Applications Connect between sources and displaysDrivers are wire elimination for install and freedom of component placementRequirementsBandwidthEach MPEG2 HD Stream MbpsTwo full rate streams required for PIPHandheld can be used for PIP viewing or channel surfing (SD stream)RangeMedia center to display or handheldAnywhere in the room (<10m)QoS with low latencyChannel change, typing, gamersAvailable Now: both SD and HD
62 Content Transfer: Mobile Devices ApplicationsSmartphone/PDA, MP3, DSCMedia Player, Storage, displayRequirementsMobile device storage sizesFlash 5, 32, 512, 2048 … MBHD 4, …, 60+ GBRange is near device (< 2m)User requires xfer time < 10sLow Power Use CasesImages from camera to storage/networkMP3 titles to music playerLow Power & High Data Rate UseExchange your music & dataMPEG4 movie (512 MB) to playerPrint from handheldMount portable HD
63 Stream DV or MPEG DS-UWB is just a shift register Content StreamingUse CasesApplicationsDigital video camcorder (DVC)Smartphone/PDS, Media playerRequirementsRange is in view of display (< 5m)DV Format 30 Mbps with QoSMPEG 2 at 12-20MbpsPower budget < 500 mWStream DV or MPEG DS-UWB is just a shift registerStream presentation from Smartphone/PDA to projectorChannel surf and PIPto handheld
64 References K. Siwiak and D. McKeown, Ultra-Wideband Radio Technology, Wiley: UK, 2004. Mohammad Ghavami, Lachlan Michael, Ryuji Kohno. Ultra-Wideband Signals and Systems in Communication Engineering, John Wiley & Sons, Ltd, 2004.M.-G. Di Benedetto and G. Giancola, Understanding Ultra Wide Band radio Fundamentals, Prentice Hall, 2004.Ian Oppermann. UWB: Theory and Applications. John Wiley & Sons, Ltd., 2005. Xiaomin Chen and Sayfe Kiaei, "Monocycle Shapes for Ultra Wideband System,“ IEEE International Symposium on Circuits and Systems, vol. 1, pp , May 2002.