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Ultra-Wideband Technology (UWB)

Ultra-Wideband Technology (UWB). EE 206A Spring, 2002 Robert Tseng Jacob Kuo. Introduction What is UWB Why it is attractive Who Basic Model Transmitter Model Receiver Model. Performance BER Pro’s and Con’s Industry Advocators Industry Contesters Conclusion. Objectives.

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Ultra-Wideband Technology (UWB)

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  1. Ultra-Wideband Technology(UWB) EE 206A Spring, 2002 Robert Tseng Jacob Kuo

  2. Introduction What is UWB Why it is attractive Who Basic Model Transmitter Model Receiver Model Performance BER Pro’s and Con’s Industry Advocators Industry Contesters Conclusion Objectives

  3. Introduction • What is UWB? • A series of very short baseband pulses with time duration in nano-seconds that exist on ALL frequencies simultaneously, like a blast of electrical Noise. • Synonyms: • Nonsinusoidal Communication Technology • Impulse Radio • Baseband Pulse Technology

  4. Why is UWB attractive? • Capacity: a channel is linearly proportional to its bandwidth. UWB can go up to 2 Giga-Hz in bandwidth. • Spread spectrum: transmission in which the data sequence occupies a bandwidth in excess of the minimum bandwidth necessary to send it. It uses only several frequencies, one at a time. • Successor to spread spectrum: UWB uses every frequency there is, use them all at same time. • Simplicity: it’s essentially a base-band system (Carrier free), for which the analog front-end complexity is far less than that for a traditional sinusoidal radio. (See Figures at next page.)

  5. Traditional Sinusoidal Radio

  6. UWB: Impulse Radio

  7. When was UWB invented and by whom? • Tough question, but easy answer! There have been many claims to the honor; however, Dr. Gerald F. Ross, currently President of ANRO Engineering, Inc., first demonstrated the feasibility of utilizing UWB waveforms for radar and communications applications back in the late 1960’s and early 1970’s. • Gerry’s pioneering insight into the value and applications of this technology over 30 years ago has been instrumental in shaping UWB technology to the point it has reached today – with applications ready to meet market demands for high-speed wireless and precision radar/positioning applications. • Gerry was recognized by the National Academy of Engineering for his efforts in ultra wideband technology, and elected a Member in 1995.

  8. Basic Transmitter Model • Transmitter Model with typical time hopping format with Pulse-Position Modulation (PPM): • Step 1: Define monocycle waveform • S(k) is the kth transmitted signal • w(t) represents the transmitted monocycle waveform • Step 2: Shift to the beginning of Time frame • Tf is the pulse repetition time or frame time • j is the j th monocycle that sits at the beginning of each time frame.

  9. Step 3 – Pseudorandom Time Hopping • To eliminate catastrophic collisions in multiple accessing • {Cj (k) } are time hopping code, periodic pseudorandom codes • Tc is the additional time delay that associate with the time hopping code • Step 4 – Data Modulation • {dj (k) } is the primary data sequence of the transmitter • Data are transmitted every Ns monocycles per symbol • The symbol δ is the time shift that applies to the monocycle, and we define such operation happens when 1 is transmitted.

  10. Receiver Block Diagram for the reception of the first user’s signal

  11. Receiver Model • Signal at Receiver • Aks(k) models the attenuation of transmitter k’s signal • N(t) is the white Gaussian noise • tauk is time asynchronisms between clocks of transmitter and the receiver • Correlation template signal • V(t) is the pulse shape defined as the difference between two pulses shifted by the modulation parameter δ. It will then be correlated with the received signal for a statistical test

  12. The optimal decision rule (one monocycle) • Pulse correlator output = αj • Test statistic = α (one symbol) • if α >0 , the symbol transmitted is 0, else it is 1

  13. Performance • With simulation studies, to maintain BER of 10-3, 10-4, and 10-5 in a communication system with no error control coding, SNR spec must be 12.8 dB, 14.4 dB, and 15.6 dB. • We shall see the next figure, which the number of users versus additional required power (Δ P) for multiple access operation with ideal power control is plotted.

  14. Pros • High data capacity. • Multiple Access provided by time hopping scheme. Can support close to 30,000 users at 19.2kbps with BER of 10-3 or a 6 users system with a peak speed of 50mbps. • Low power. • Transmitting at microwatts (one tenth thousandth power of cell phone) results in very low harmful interference to other radio systems. Usually below the noise floor and undetectable. • Longer battery life for mobile devices. • Resilient to distortions and fading (Great for indoor usage). • Spread spectrum property overcomes frequency selective fading. • High information redundancy and frequency diversity provides protection against multi-path distortion. • Simplicity translate to lower hardware cost. • No carrier frequency translate analog front-end has simpler implementation than traditional sinusoidal radio. • Security • UWB is inherently secure: Only a receiver that knows the schedule of the transmitter can assemble the apparently random pulses into a coherent message.

  15. Cons • Interference with GPS. • Global positioning satellite currently have more than 10 million users and it’s primarily applications are used for the safety of public. (I.e. aircraft flight and approach guidance.) UWB presents a problem to GPS because their frequency overlaps, and GPS signal is particular sensitive to interference (It as SNR level around –164 dBW.) • Limited on range • Output power is limited in order to keep down the noise floor due to its overlapping frequency bandwidth with other radio systems. • One kilometer with high gain antenna. • Ten to twenty meter with regular antenna. • Affects on economy and current businesses. • Speculations on UWB making current billion dollar FCC licensed frequencies worthless. • Increased competition for local cable or phone company. Making their existent investments on cable and equipments obsolete. • Side Note. • FCC adopted a First Report and Order that permits the marketing and operation of certain types of new products incorporating UWB technology, Feb 14,2002. • Biggest loser: Increase the noise floor level for radio astronomer.

  16. UWB Advocators • Intel • First - Intel is actively engaging the industry to help determine a reliable model that systems engineers can use to help study the performance of UWB systems. • Second – Intel is investigating several receiver designs that will help to improve the robustness and long-term viability of this technology. • Third - the feasibility for high-level silicon integration in order to yield a very low-cost and low-power solution. • Intel itself has not yet decided to enter the market for UWB chips or systems, according to Manny. The Santa Clara, Calif.-based company is still in the R&D phase with the technology. • Using discrete radio-frequency (RF) components, Intel demonstrated a UWB-enabled system that supported data rates at speeds of 100 megabits per second, said Ben Manny, director of wireless technology development at Intel Architecture Labs. The company aims to push this wireless technology to 500 Mbits per second, Manny said in an interview at IDF.

  17. Time Domain Corp., • based in Huntsville, Ala., has petitioned the FCC for a waiver so that by the middle of next year, it can begin selling a system that will permit police officers and special weapons and tactics teams to see through walls and doors to detect the location of people. The company is also planning a covert communications system that will both carry voice communications and display locations of a counter-terrorism or SWAT team's members. • Time Domain has harnessed UWB technology in silicon-based solutions, which are embodied in a family of PulsON® chipsets. The PulsON® chipset has been designed to enable hundreds of applications in existing products as well as future products and industries. Time Domain's chipsets are expected to be available in 2002. Time Domain is now producing PulsON® Application Demonstrators (PADs), which integrate the first generation PulsON® 100 Silicon Germanium chips into a single PC board. Early adopters are joining our PulsON® Developer Program(SM) to incorporate PulsON silicon solutions into their applications and products. • Siemens invested 5 million in Time Domain • Qwest bought 5% of time domain Other supporters: Motorola, Siemens, IBM, Sony

  18. Start-Up Companies • Aether Wire & Location www.aetherwire.com • General Atomics www.ga.com • Multispectral Solutions www.multispectral.com • Pulse-Link www.pulse-link.net • Pulsicom Technologies (Israel) www.pulsicom.com • Time Domain www.timedomain.com • XtremeSpectrum www.xtremespectrum.com • Zircon www.zircon.com

  19. UWB Contesters • Sprint PCS (PCS ) and other wireless carriers, which paid a king's ransom for their spectrum rights, fear the interference caused by UWB. • Still others, including the US Department of Defense and the airline industry, are heavily involved in other wireless technologies (e.g. GPS), felt that UWB should not be allowed at all below 4.2 GHz, 6 GHz or even higher.

  20. Conclusion • Impact on the market • Troubles in existing communication businesses • UWB offers a better and cheaper service • Value of existing infrastructure drops • UWB will occupy certain part of radio spectrum that are exclusively licensed to some companies • Boosting up the range of high-speed internet services • Solves the last-mile problem

  21. Losers • Local phone companies, cable TV companies, mobile phone companies and internet service providers, who have old infrastructure • Regulated communication companies who has exclusive license to some parts of the radio spectrum • Radio Astronomers, the level of noise threshold is raised. • Winners • Companies best adapted to UWB • PCS vendor: new UWB radio to its short range sites • Optical backbone provider: UWB increases it’s bandwidth • TV networks can extend their market range.

  22. References • Impulse RadioRobert.A. Scholtz and Moe Z Win Invited Paper, IEEE PIMRC ’97, Helsinki • Impulse Radio: How It WorksMoe Z Win and Robert.A. Scholtz IEEE Communications Letters, Vol. 2, No. 1, January 1998 • Multiple Access with Time-Hopping Impulse ModulationR.A. Scholtz Invited Paper, MILCOM ’93 Conference • Assessing Interference of Ultra-Wideband Transmitters with the Global Positioning System - A Cooperative Study G. Roberto Aiello and Gerald D. Rogerson, Interval Research Corporation* Per Enge, Department of Aeronautics and Astronautics, Stanford University • The 100 Mile-Per-Gallon CarburetorHow Ultra Wide Band May (or May Not) Change the WorldBy Robert X. Cringelyhttp://www.pbs.org/cringely/pulpit/pulpit20020124.html • Webb on Wireless William Webb kicks off his column for Wireless Europe by arguing that ultra-wide band will not replace WLAN or Bluetooth technologies. By William Webb http://wireless.iop.org/article/feature/3/1/8 • NEW PUBLIC SAFETY APPLICATIONS AND BROADBAND INTERNET ACCESS AMONG USES ENVISIONED BY FCC AUTHORIZATION OF ULTRA-WIDEBAND TECHNOLOGY by Federal Communications Commission http://www.fcc.gov/Bureaus/Engineering_Technology/News_Releases/2002/nret0203.html

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