Introduction to Ultra WideBand Systems Chia-Hsin Cheng

Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signals UWB in IEEE 802 Standards The Application of UWB

Introduction The 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.

UWB Transmitter Defined UWB transmitter signal BW: Or, BW ³ 500 MHz regardless of fractional BW fu-fl 2 ³ 0.20 fu+fl Where: fu= upper 10 dB down point fl = lower 10 dB down point Source: US 47 CFR Part15 Ultra-Wideband Operations FCC Report and Order, 22 April 2002: http://www.fcc.gov/Bureaus/Engineering_Technology/Orders/2002/fcc02048.pdf

UWB: Large Fractional Bandwidth CDMA: 1.288Mcps/1.8 GHz 0.07% bandwidth one “chip” UWB NB 6% bandwidth 20% bandwidth Power Spectral Density (dB) -80 -40 Frequency (GHz) 3 6 9 12 15 Random noise signal 100% bandwidth

Large Relative (and Absolute) Bandwidth Narrowband (30kHz) Part 15 Limit ( -41.3dBm/Hz ) Wideband CDMA (5 MHz) UWB (Several GHz) Frequency UWB is a form of extremely wide spread spectrum where RF energy is spread over gigahertz of spectrum Wider than any narrowband system by orders of magnitude Power seen by a narrowband system is a fraction of the total UWB signals can be designed to look like imperceptible random noise to conventional radios

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 B Capacity per channel (bps) µ log(1+S/N) Increase B Increase S/N, use higher order modulation Increase number of channels using spatial separation (e.g., MIMO)

Throughput Low Power UWB Comparable to High Power Wireless Systems UWB throughput between 802.11a and b

UWB Properties Extremely difficult to detect by unintended users Highly Secured Non-interfering to other communication systems It appears like noise for other systems Both Line of Sight and non-Line of Sight operation Can pass through walls and doors High multipath immunity Common architecture for communications, radar & positioning (software re-definable) Low cost, low power, nearly all-digital and single chip architecture

Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signals UWB in IEEE 802 Standards The Application of UWB

The history of UWB Technology Before 1900: Wireless Began as UWB Large RF bandwidths, but did not take advantage of large spreading gain 1900-40s: Wireless goes ‘tuned’ Analog processing: filters, resonators ‘Separation of services by wavelength’ Era of wireless telephony begins: AM / SSB / FM Commercial broadcasting matures, radar and signal processing 1970-90s: Digital techniques applied to UWB Wide band impulse radar Allows for realization of the HUGE available spreading gain Now: UWB approved by FCC for commercialization For further details, refer to ref.[1]

What UWB is Today 7,500 MHz available spectrum for unlicensed use US operating frequency: 3,100 – 10,600 MHz Emission limit: -41.3dBm/MHz EIRP Indoor and handheld systems Other restrictions and measurement procedures in Report and Order UWB transmitter defined as having the lesser of Fractional bandwidth greater than 20% Occupies more than 500 MHz UWB is NOT defined in terms of Modulation or Carrierless or Impulse radio

Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signals UWB in IEEE 802 Standards The Application of UWB

Summary of the FCC Rules Significant protection provided for sensitive systems GPS, Federal aviation systems, etc. Lowest emission limits ever by FCC Incorporates NTIA (National Telecomm. and Info. Administration) recommendations Allows UWB technology to coexist with existing radio services without causing interference FCC opened up new spectrum for UWB transmissions One of the bands is from 3.1GHz to 10.6GHz Maximum power emission limit is - 41.3dBm/MHz

FCC UWB Device Classifications Report and Order authorizes 5 classes of devices with different limits for each: Imaging Systems Ground penetrating radars, wall imaging, medical imaging Thru-wall Imaging & Surveillance Systems Communication and Measurement Systems Indoor Systems Hand-held Systems Vehicular Radar Systems collision avoidance, improved airbag activation, suspension systems, etc.

FCC First Report and Order Authorizes Five Types of Devices Class / Application Frequency Band for Operation at Part 15 Limits User Limitations Communications and Measurement Systems 3.1 to 10.6 GHz (different “out-of-band” emission limits for indoor and hand-held devices) No Imaging: Ground Penetrating Radar, Wall, Medical Imaging <960 MHz or 3.1 to 10.6 GHz Yes Imaging: Through-wall <960 MHz or 1.99 to 10.6 GHz Imaging: Surveillance 1.99 to 10.6 GHz Vehicular 22 to 29 GHz

UWB Emission Limits for GPRs, Wall Imaging, & Medical Imaging Systems 0.96 1.61 1.99 3.1 10.6 GPS Band Operation is limited to law enforcement, fire and rescue organizations, scientific research institutions, commercial mining companies, and construction companies. Source: www.fcc.gov

UWB Emission Limits for Thru-wall Imaging & Surveillance Systems 0.96 1.61 1.99 10.6 GPS Band Operation is limited to law enforcement, fire and rescue organizations. Surveillance systems may also be operated by public utilities and industrial entities. Source: www.fcc.gov

UWB Emission Limit for Indoor Systems 0.96 1.61 1.99 3.1 10.6 GPS Band Source: www.fcc.gov

Proposed UWB Emission Limit for “Outdoor” Systems 0.96 1.61 1.99 3.1 10.6 GPS Band Proposed in preliminary Report and Order, Feb. 14, 2002. Source: www.fcc.gov

Actual UWB Emission Limit for Hand-held Systems 0.01 0.1 1 10 100 -80 -70 -60 -50 Frequency, GHz -40 EIRP, dBm/MHz UWB Band-width must be contained here First Report and Order, April 22, 2002.

Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signals UWB in IEEE 802 Standards The Application of UWB

UWB Signals Monocycle Shapes for UWB Data Modulation Modulation Schemes

Monocycle Shapes for UWB Monocycle shapes will affect the performance Listed monocycles’ duration is 0.5ns Gaussian pulse Gaussian Monocycle Scholtz’s Monocycle Manchester Monocycle RZ- Manchester Monocycle Sine Monocycle Rectangle Monocycle For further details, refer to ref.[4]

Monocycle Shapes for UWB (cont.) Gaussian Pulse

Monocycle Shapes for UWB (cont.) Gaussian monocycle Similar to the first derivative of Gaussian pulse

Monocycle Shapes for UWB (cont.) Scholtz’s monocycle Similar to the second derivative of Gaussian pulse

Monocycle Shapes for UWB (cont.) Manchester Monocycle It has amplitude A during half of the monocycle width and has amplitude –A during the other half.

Monocycle Shapes for UWB (cont.) RZ- Manchester Monocycle It has amplitude A and –A only a portion of each half monocycle width.

Monocycle Shapes for UWB (cont.) Sine Monocycle Just a period of sine wave

Monocycle Shapes for UWB (cont.) Rectangle Monocycle It has uniform amplitude A during the whole pulse width.

Data Modulation A 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)

Modulation Schemes Many 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 concepts Time-hopping (TH) technique Direct-Sequence (DS) technique Multi-band (MB) technique

TH-UWB TH-PPM Str(t) Tc t Tf Ts : data symbol time 1. transmitting 0 pulse wtr(t) Str(t) Tc t Tf Ts : data symbol time

TH-UWB TH-PPM 2 . transmitting 1 d d d d Str(t) Tc t Tf Ts

DS-UWB DS-UWB

Multiband UWB Refer to OFDM course

Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signals UWB in IEEE 802 Standards The Application of UWB

UWB in IEEE 802 Standards IEEE 802 Organization IEEE 802.15.3a

IEEE 802 Organization LAN/MAN Standards Committee (Wireless Areas) WLAN™ IEEE 802.11 WPAN™ IEEE 802.15 WMAN™ IEEE 802.16 MBWA IEEE 802.20 Regulatory TAG IEEE 802.18 Coexistence TAG IEEE 802.19 802.15.1 “Bluetooth” 802.15.3 “High Data Rate” MAC & 2.4 GHz PHY Task Group 3a Alt PHY (UWB) 802.15.2 Coexistence 802.15.4 “Zigbee” 2.4 GHz Study Group 4a (UWB?) Mini-Glossary: WLAN-wireless Local Area Network; MAN-Metropolitan Area Network; TAG-Technical Advisory Group;-MBWA-Mobile Broadband Wireless Access Based on: “Overview of 802.15.3 and 3a,” R. F. Heile, Workshop on Current Developments in UWB, Institute for Infocomm Research, Singapore

IEEE Project 802 Local and Metropolitan Area Network Standards Committee Accredited by ANSI, Sponsored by IEEE Computer Society Ethernet, Token Ring, Wireless, Cable Modem Standards Bridging, VLAN, Security Standards Meets three times per year (400-600 individuals, 15% non-US) Develops equivalent IEC/ISO JTC 1 standards JTC 1 series of equivalent standards are ISO 8802-nnn IEEE URLs 802 http://grouper.ieee.org/groups/802/ 802.15 http://grouper.ieee.org/groups/802/15/

Standards : Range and Data Rate

Candidate UWB Systems

802.15.3a – high data rate WPAN standard Direct sequence (DS-UWB) Championed by Motorola/XtremeSpectrum Classic UWB, simple pulses, 2 frequency bands: 3.1-4.85GHz, 6.2-9.7GHz CDMA has been proposed at the encoding layer Spectrum dependent on the shaping filter – possible differing devices worldwide Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) Intel/TI/many others Similar in nature to 802.11a/g 14 528MHz bands (simplest devices need to support 3 lowest bands, 3.1GHz – 4.7 GHz) Spectrum shaping flexibility for international use

Detail of DS-CDMA Candidate for 802.15.3a Multi-band DS-CDMA Physical Layer Proposal Summary from IEEE document 15-03-0334-02-003a-Merger-2-CFP-Presentation.ppt

3 Spectral Modes of Operation Two Band DS-CDMA Low Band High Band 3 4 5 6 7 8 9 10 11 3 4 5 6 7 8 9 10 11 Low Band (3.1 to 5.15 GHz) 25 Mbps to 450 Mbps High Band (5.825 to 10.6 GHz) 25 Mbps to 900 Mbps Multi-Band 3 Spectral Modes of Operation With an appropriate diplexer, the multi-band mode will support full-duplex operation (RX in one band while TX in the other) 3 4 5 6 7 8 9 10 11 Multi-Band (3.1 to 5.15 GHz plus 5.825 GHz to 10.6 GHz) Up to 1.35 Gbps

Joint Time Frequency Wavelet Family Example Duplex Wavelet Mid Wavelet Long Wavelet 3 4 5 6 7 8 9 10 11 -40 -35 -30 -25 -20 -15 -10 -5 GHz dB -1 1 -0.5 0.5

Spectral Flexibility and Scalability PHY Proposal accommodates alternate spectral allocations Center frequency and bandwidth are adjustable Supports future spectral allocations Maintains UWB advantages (i.e. wide bandwidth for multipath resolution) No changes to silicon Example 2: Support for hypothetical “above 6 GHz” UWB definition Example 1: Modified Low Band to include protection for 4.9-5.0 GHz WLAN Band 3 4 5 6 7 8 9 10 11 Note 1: Reference doc IEEE802.15-03/211 3 4 5 6 3 4 5 6

Detail of OFDM Candidate for 802.15.3a Multi-band OFDM Physical Layer Proposal Summary from IEEE document 03267r1P802-15_TG3a-Multi-band-OFDM-CFP-Presentation.ppt

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.

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.

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)

802.15.4a – alternate PHY for 802.15.4 Addresses the following Globally deployable Compatible / interoperable with 802.15.4 Longer range Higher reliability Ranging/localization support Lower latency & support for mobility Low cost Current UWB systems not quite suitable 90 nm CMOS is expensive, 200 mW is a lot of power Still in early stages Proposals 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)

Outlines Introduction The history of UWB UWB Regulations (FCC Rules) UWB signals Standards of IEEE 802 The Application of UWB

The Application of UWB Ultra-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 sensors Position location and tracking Radar

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 options Consumer devices like,TV (w internet access), Home Theatre, video gaming console, DVD player, STB, DVCR, Home Stereo, TiVo Interconnectivity 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 presentations conference rooms training rooms automation or control functions Industry applications for control and surveillance Healthcare industry for monitoring and wearable sensors, patient monitoring Source: doc.: IEEE 802.15-01/036r0

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

3G and beyond 4G POTENTIAL FOR UWB

Potential Application Scenarios Intelligent Wireless Area Network (IWAN) ► Wireless Body Area Network (WBAN) ▼ ▲ Hot-spot Wireless Personal Area Network (WPAN) Sensor, Positioning, and Identification Network (SPIN) ▼ Outdoor Peer-to-Peer Networking (OPPN) ◄

UWB Consumer Applications Freescale Semi. Home Entertainment Mobile Devices Computing Automotive

Entertainment Applications Connect between sources and displays Drivers are wire elimination for install and freedom of component placement Requirements Bandwidth Each MPEG2 HD Stream 20-29 Mbps Two full rate streams required for PIP Handheld can be used for PIP viewing or channel surfing (SD stream) Range Media center to display or handheld Anywhere in the room (<10m) QoS with low latency Channel change, typing, gamers Available Now: both SD and HD

Content Transfer: Mobile Devices Applications Smartphone/PDA, MP3, DSC Media Player, Storage, display Requirements Mobile device storage sizes Flash 5, 32, 512, 2048 … MB HD 4, …, 60+ GB Range is near device (< 2m) User requires xfer time < 10s Low Power Use Cases Images from camera to storage/network MP3 titles to music player Low Power & High Data Rate Use Exchange your music & data MPEG4 movie (512 MB) to player Print from handheld Mount portable HD

Stream DV or MPEG DS-UWB is just a shift register Content Streaming Use Cases Applications Digital video camcorder (DVC) Smartphone/PDS, Media player Requirements Range is in view of display (< 5m) DV Format 30 Mbps with QoS MPEG 2 at 12-20Mbps Power budget < 500 mW Stream DV or MPEG DS-UWB is just a shift register Stream presentation from Smartphone/PDA to projector Channel surf and PIP to handheld

References [1] K. Siwiak and D. McKeown, Ultra-Wideband Radio Technology, Wiley: UK, 2004. [2] Mohammad Ghavami, Lachlan Michael, Ryuji Kohno. Ultra-Wideband Signals and Systems in Communication Engineering, John Wiley & Sons, Ltd, 2004. [3]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. [4] Xiaomin Chen and Sayfe Kiaei, "Monocycle Shapes for Ultra Wideband System,“ IEEE International Symposium on Circuits and Systems, vol. 1, pp. 597-600, May 2002.