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Doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area.

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Presentation on theme: "Doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area."— Presentation transcript:

1 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Introduction to Chirp Spread Spectrum (CSS) Technology Date Submitted: November 11, 2003 Source: John Lampe, Zbigniew Ianelli Company: Nanotron Technologies Address: Alt-Moabit 61, 10555 Berlin, Germany Voice: +49 30 399 954 135, FAX: +49 30 399 954 188, E-Mail: j.lampe@nanotron.com Re: Discussion of interesting RF technology Abstract:Tutorial Presentation on CSS for IEEE 802 – part 1 Purpose:November Plenary Tutorial #4. Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 2 Introduction to Chirp Spread Spectrum (CSS) Technology presented by Zbigniew Ianelli Nanotron Technologies GmbH Berlin, Germany www.nanotron.com

3 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 3 Contents A brief history of Chirp pulses Characteristics of Chirp pulses The basic Chirp signal Properties of signal forms Scalable technology How to code using CSS Key Properties of CSS

4 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 4 A brief history of Chirp pulses Used by whales and dolphins Patent for radar applications in 1944 by Prof. Hoffmann Further developed by Sidney Darlington (Lifetime IEEE Fellow) in 1947 (Pulse Compression Radar) Patented by Canon for data transmission in fiber optic systems Chirp Spread Spectrum for commercial wireless data transmission is investigated since 1997

5 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 5 Characteristics of Chirp pulses A chirp pulse is a frequency modulated pulse. Its duration is T; within this time the frequency is changing in a monotonic manner from a lower value to a higher one (Up-Chirp) or reverse (Down-Chirp). The difference between these two frequencies is a good approximation for the bandwidth B of the chirp pulse. Up-Chirp in the time domain (roll-off factor 0.25) Spectrum of the chirp pulse with bandwidth B and a roll-off factor of 0.25 B S(f) f

6 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 6 The basic Chirp signal Chirp pulse: Sinc pulse (baseband): Sinc pulse (RF band):

7 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 7 Properties of signal forms in the air and baseband interfaces Chirp pulses for the RF channel: High robustness (BT>>1) Wideband signal Constant envelope of the RF waveform Constant, uniform PSD (Power Spectral Density) well controlled spectrum in very simple way Sinc pulses in the baseband: High speed (Bδ=1) Easy signal processing (threshold detector)

8 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 8 Scalable Technology Frequency spreading: Basic information theory tells us that CSS benefits when the bandwidth B of the Chirp pulse is much higher than the data rate R: B >> R Time spreading: The data rate can scale independently of the BT product. The duration T of the Chirp pulse can be chosen freely. A signal with a very high BT product can be achieved, which transforms into a very robust signal in the channel.

9 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 9 Scalable Technology (continued) Excellent range – data rate scalability: Preferred for system where range and/or data rate requirement varies rapidly. Especially promising for wideband or ultra wideband system where available frequency bandwidth B is much higher than the data rate R

10 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 10 How to code using CSS Modulation techniques: On-Off-Keying (OOK), for example: Up-Chirp = 1; Null = 0 allows 2 independent coexisting networks Superposed Chirps (4 possible states): Null/Up-Chirp/Down-Chirp/ Superposition of Up- and Down-Chirp allows one network with double the data rate t f 1 0 1 0 0 1 f LO f HI Chirp pulse OOK with Null and Up-Chirp

11 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 11 Key Properties of CSS High robustness: Due to the high BT product, chirp pulses are very resistant against disturbances. Multipath resistant: Due to the broadband chirp pulse, CSS is very immune against multipath fading; CSS can even take advantage of RF echoes. Low power consumption: CSS allows the designer to choose an analog implementation, which often consumes much less power. Low latency: CSS needs no synchronization; a wireless connection can be established very quickly.

12 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 12 Mobility Properties of CSS Resistance against Doppler effect: The Doppler effect causes a frequency shift of the chirp pulse, which introduces a negligible shift of the baseband signal on the time axis. Example: Bandwidth of the chirp80 MHz Duration of the chirp1 µs Center frequency of the chirp (ISM band)2.442 GHz Relative speed between transmitter and receiver2000 km/h Frequency shift due to Doppler effect4.52 kHz Equivalent shift of the message on the time axis56.5 ps Note: 2000 km/h is equivalent to 1243 miles/hour

13 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 13 Coexistence Properties of CSS Immune to in-band interferer: Scalable processing gain (determined by BT product of the chirp) enables selection of appropriate immunity level against in-band interferences. Example: Bandwidth B of the chirp64 MHz Duration time T of the chirp1 µs Center frequency of the chirp (ISM band)2.442 GHz Processing gain, BT product of the chirp18 dB E b /N 0 at detector input (BER=0.001)14 dB In-band carrier to interferer ratio (C/I @ BER=0.001) -4 dB

14 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 14 Some Applications and Measurements of Chirp Spread Spectrum (CSS) Technology presented by John Lampe Nanotron Technologies GmbH Berlin, Germany www.nanotron.com

15 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 15 Applications requiring mobility faster than 11 mph, such as: –Tire pressure –Assets in vehicles (in-car communications) –Drive-by Drop boxes Drive-by AMR –Toll booths Applications requiring robustness or fewer retransmissions in multipath environments, such as: –Industrial mission-critical –Airplanes –Ships / engine rooms –Gaming –New WINA alliance one example of this need Applications requiring ranging accuracy better than 0.5 meters, such as: –Asset tracking (active RFID) –Personnel tracking –Motion detection –Automatic network installation New Applications / Global Markets

16 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 16 Applications desiring extended range, such as: –Meter Reading –Building Automation –And other longer-range applications where repeaters are not practical Enhanced Applications / Markets

17 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 17 Evaluation Board Includes: RF IC SAW filter Optimized balun for asymmetrical antenna operation Crystals

18 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 18 Outdoor testing with CSS Test environment: Straße des 17. Juni - Siegessäule

19 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 19 Comparing CSS to DECT Outdoors

20 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 20 d=23 m, P out = -15 dBm = 32 µW, G=1,5 dB, BER = 10 -3 d=15 m, P out = -15 dBm = 32 µW, G=1,5 dB, BER = 10 -3 Result: d = 23 m with P out = -15 dBm Calculated: d = 50 m with P out = +10 dBm, = 3 Indoor testing with CSS

21 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 21 Indoor testing with CSS d=5 m, P out = -30 dBm= 1 µW, G = 1,5 dB, BER = 10 -4 d=26 m, P out = 8 dBm = 6,3 mW, G = 1,5 dB, BER = 10 -3 CSS transmits 1Mbps with P out = 1 µW over 5m and with 6,3mW over 26m Load-bearing Walls

22 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 22 Outdoor Link-Budget Link budget without cable losses or antenna-gain, best case: LB best = 103 dB Outdoor free space propagation: distance ~ link- budget with = 2.1 … 2.3 But: Outdoor propagation is not always free space propagation, due to e.g. hills, trees, houses, … Therefore: Measurements have to be done! d = 940 m

23 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 23 Testing CSS on Hahneberg, Berlin-Spandau 4626±10 m 3404±10 m 739±10 m Ref P1 P2 P3 P4 940±10 m

24 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 24 Outdoor testing with CSS 4626±10 m P out = 24 dBm = 250 mW 3404±10 m 739±10 m P out = 7 dBm = 5 mW Ref P1 P2 P3 P4 940±10 m P out = 9 dBm = 7.9 mW

25 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 25 Outdoor testing with CSS Measurement Challenge: Teufelsberg 6483 m distance 7.7 dBm output power 18 dB antenna gain No FEC BER 10E-3

26 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 26 Output Power @ antenna Range @ BER=10 -3 7 dBm = 5 mW740 m 9 dBm = 7.9 mW940 m 26 dBm = 400 mW6400 m 30 dBm = 1 W9800 m G ant = 1 dB P out = 9 dBm, d = 940 m P out = 7 dBm, d = 740 m P out = 26 dBm, d = 6.4 km P out = 30 dBm, d = 9.8 km CSS Outdoor Test Summary

27 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 27 Need for Standardization Ole Ploug R&D Manager Central Controls R&D Refrigeration and Air Conditioning www.danfoss.com

28 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 28 Summary Introduced CSS technology Explained behavior and benefits Suggested some additional applications that can be satisfied Shown test results that demonstrate some of CSS capabilities Shown one customers application requirements

29 doc.: IEEE 802.15-03-0460-00-0000 Submission November 2003 Lampe, Ianelli, NanotronSlide 29 Conclusions CSS has qualities of both spread spectrum and UWB. CSS enhances robustness and range CSS adds mobility CSS can be implemented with todays technologies CSS is a global solution


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