1 / 26

WE2F-01

WE2F-01. Millimeterwave Imaging Sensor Nets: A Scalable 60-GHz Wireless Sensor Network Munkyo Seo*, B. Ananthasubramaniam, M. Rodwell and U. Madhow Electrical and Computer Engineering University of California, Santa Barbara CA 93106, USA. Outline. Motivation

don
Download Presentation

WE2F-01

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WE2F-01 Millimeterwave Imaging Sensor Nets: A Scalable 60-GHz Wireless Sensor Network Munkyo Seo*, B. Ananthasubramaniam, M. Rodwell and U. Madhow Electrical and Computer Engineering University of California, Santa Barbara CA 93106, USA

  2. Outline • Motivation (1) A scalable, simplistic approach to the wireless sensor network (2) Exploit millimeter-wave frequencies • Proposed Approach • Collector System • 60-GHz Passive sensors • Indoor Radio Experiment

  3. Wireless Sensor Networks (WSN) • Goal: Distributed data collection & localization to obtain an information map, D[x,y,z,t] • Many scientific, industrial and military applications • Environmental monitoring, • Wildlife research, • Seismic activity detection, • remote sensing, • battle field surveillance, • border policing, • planetary exploration, • Body-area network, • …

  4. Current WSN Practice • Data collection: Multi-hop based communication • Low-power communication • Not very suitable for large-scale networks • Localization: Fixed ID code, GPS, acoustics, etc • Tends to make sensors costly, complex    From Akyildiz et al, IEEE Comm. Mag., Aug. 2002

  5. Simplistic Sensor Approach Sensor with minimal functionality Move all complexity to the collector (1) Collector sweeps a beam (2) Sensors receive, modulate and transmit it back. (3) Collector jointly detects data & location DATA sensor Range code Sensor local data

  6. Simplistic Approach • Similarities with optical imaging & radar • Scalability • Communication grows linearly as # of sensors • Built-in Localization • Range resolution by a wideband range-code • Angular resolution by a narrow beam • Simplistic sensors (= low-cost, low-power) • No communication among sensors • No localization capability required. • Concerns • Need line-of-sight, complex collector signal processing

  7. Exploit Millimeter-waves Narrow Beamwidth Wide Bandwidth • Motivations: • Higher angular resolution @ same antenna aperture • Higher range resolution @ same fractional BW • High data rate • Unlicensed band @60GHz (BW>5GHz)

  8. Signal Processing Principle • Localization • Goal: Find the most likely sensor location. • How? 3-D matched filtering (M/F) • Range correlation (Tx Range code) • Azimuth correlation (w/ AGF) • Elevation correlation (w/ AGF) • Find a peak! Accuracy eventually limited by the received SNR • Data Demodulation • Goal: Retrieve the local sensing data (1? 0?) • How? Track the peak Maximum- likelihood detection

  9. Round-trip Radio Link 6~16dB/km @ 60-GHz band 60-GHz +/- fdelta 60-GHz 7dBm 23dBi 40dBi 7dBi -3dB 25m (current prototype) 25dBm 40dBi 40dBi 7dBi -3dB 200m (possible ext.) 25dBm 40dBi 40dBi 7dBi 80dB 1,600m (“active” sensor)

  10. 60-GHz Collector Block Diagram Directivity= 40dB (2 deg) 0.4m@R=10m 4.0m@R=100m Range code: 20-MHz PRBS (26-1) Single-chip= 7.5m, Max. field size= 470m D=23dBi P=7dBm D=40dBi

  11. 60-GHz Collector Transceiver Rx Antenna (40dB) Tx Antenna (23dB) Remote-controlled Positioner (Az, El) Transceiver board

  12. 60-GHz Collector System • Transceiver with all required instruments. • Mounted on a mobile cart.

  13. Measured Antenna Gain Function (AGF) AGF = (TX ANT) (RX ANT) = (23dB Horn) (40dB Cassegrain) 1 Magnitude 0.5 0 -4 -3 -2 -1 0 1 2 3 4 Azimuth, Elevation (degree)

  14. ¼ λ XTAL MS - to - SL transition 16 - bit Local ¼ λ PIN diode (MA-COM) data 60-GHz Passive Sensor: Block Diagram • Receive, modulate and re-radiate the beam • Simplicity, low cost, robustness, etc Open-slot Antenna BPSK Modulator Baseband fdelta= 50MHz

  15. 60-GHz Passive Sensor: Considerations • Antenna • Patch type? • Slot-type? • Open-slot type? • Substrate: RO4003C • 0.2mm, Er=3.38 • Loss= 0.07dB/mm, Q=20 • Standard low-cost PC-board manufacturing • Min. line width/spacing = 5mil (125um) • This favors high Z0 (=90ohm) PIN diode (flip-chip) Size: 15mm x 10mm

  16. Modulator Impedance a • Switches between two impedance states. • ~180 degree relative phase shift • BPSK Modulation b 65GHz 60GHz Bias ON (7mA) 55GHz 55GHz Bias OFF 60GHz 65GHz

  17. 0 -10 dB(S(1,1)) -20 -30 65 70 50 55 60 Freq (GHz) Linearly-Tapered Open-Slot Antenna HFSS Beam Pattern (7dBi) 0dB Input Match -10dB ` HPBW= 50 deg

  18. CMOS Passive Sensor (under fab.) • 3-channel sensor (90-nm CMOS) • dc power = 0.5~3uW • Contains a BPSK modulator and low-power, voltage-controlled ring-oscillator • Flip-chip interface to ANT. For low-power operation, CMOS integration is necessary Layout (1mm2)

  19. Indoor Radio Experiment sensor

  20. Received Power vs Range Measured Calculated -80 -90 -100 Received Power (dBm) -110 -120 100 101 Range (m)

  21. 0 0 -10 -10 -20 -20 -30 -30 -40 -40 -50 -50 0.85 0.90 0.95 1.00 1.05 0.85 0.90 0.95 1.00 1.05 Received Spectrum (RX-IF2) Sensor ON (~3m) Sensor OFF Power (dBm) Freq. (GHz) Freq. (GHz)

  22. 2-D Localization (M/F output) Sweep 15.6 deg Step= 0.6 deg Single sensor azimuth collector radial Two sensors collector Field size: 12x0.6 m2

  23. 3-D Localization (M/F output) 1.5 deg 1.0 deg 0.5 deg 0 deg Elevation -0.5 deg -1.0 deg -1.5 deg

  24. Data Demodulation 0.05 Reference PRBS 0 -0.05 0.2 Received signal (I) 0 -0.2 4 Cross-correlation 2 0 1111 0001 001 0 111 00 0.2 Demodulated Data (10kbps) 0 -0.2

  25. Summary • Millimeter-wave wireless sensor network • Large-scale network w/ simplistic sensors • 60-GHz prototype • Collector • PIN-diode based passive sensor • CMOS sensor (dc power: uW level) • Indoor radio experiment (<12m) • Data demodulation, 3D localization • Next • uW CMOS sensor module • Large-scale radio experiment

  26. Thank you. Questions?

More Related