Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [CSS-Comparisons-and-Informative-Papers] Date Submitted: [15 November 2004] Source: [John Lampe] Company [Nanotron Technologies GmbH] 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: [This submission is in response to the TG4a CFI] Abstract: [This submission includes comparisons of CSS to some requirements from TG4a’s SCD, and CSS information.] Purpose: [This document provides additional background information supporting the proposal of CSS as the baseline PHY for TG4a] 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. John Lampe, Nanotron Technologies, GmbH

2. CSS: Comparisons, and Informative Papers presented by John Lampe Nanotron Technologies GmbHBerlin, Germany www.nanotron.com John Lampe, Nanotron Technologies, GmbH

3. Key Properties of CSS • High robustness: • Due to the high BT product and their asynchronous nature, chirp systems are very resistant against disturbances. • Multipath resistant: • Due to the frequency spreading of chirp pulses, CSS is very immune against multipath fading; CSS can even take advantage of RF echoes. John Lampe, Nanotron Technologies, GmbH

4. Key Properties of CSS • Long range: • Due to high system gain, as well as noise, interference and fading resistance, CSS has exceptional range for a given transmit power and conditions. • Location awareness: • CSS gives the ability to determine the distance (range) between two stations. • Low power consumption: • CSS allows the designer to choose a simple analog implementation, which often consumes much less power. John Lampe, Nanotron Technologies, GmbH

5. Key Properties of CSS • Low PHY latency: • With CSS a wireless connection can be established very quickly because synchronizations on carrier frequency and data clock are not required. • Antenna position: • Reception is possible with almost any antenna position due to the wide bandwidth. John Lampe, Nanotron Technologies, GmbH

6. Selection Criteria Document Overview 3.1 Unit Manufacturing Cost/Complexity (UMC) In the current implementations of CSS from Nanotron, Tx and Rx are approximately equal size. For 0.35 µm SiGe BiCMOS: the PHY portion of the chips are about 8 mm2. Newer chip designs using CMOS are underway. The receiver and transmitter in a CSS system can tolerate significant frequency offset without significant loss of processing gain. [1] 3.3 Signal Robustness Chirp uses time and frequency correlation to minimize non-desirable signals. Multipath and other RF is reduced by the processing gain. [2, 3] John Lampe, Nanotron Technologies, GmbH

7. Selection Criteria Document Overview 3.3.3 Coexistence • CSS’s power spectral density is lower than that for IEEE 802.15.4 O-QPSK for the same transmit power • Low IEEE 802.15.4 duty cycle enhances coexistence • Proposal’s packet duration is shorter than that of IEEE 802.15.4 due to the higher data rate • Proposal will include channelization to enhance coexistence via FDMA • Current Nanotron systems show low susceptibility to interferers; ~ -6 dB C/I John Lampe, Nanotron Technologies, GmbH

8. Selection Criteria Document Overview 3.4 Technical Feasibility Nanotron has working chips in customer pilots; additionally Nanotron has received ETSI approval for its CSS implementation and is pursuing US approval. The use of the 2.4 GHz ISM band allows this system to be immediately globally deployed. 3.5 Scalability Numerous scalability parameters such as channel bandwidth, coding method, data rate, transmit power levels, and pulse shape allow this system to be optimized to the applications John Lampe, Nanotron Technologies, GmbH

9. Selection Criteria Document Overview 5.2 Size and Form Factor Small size will result from high levels of integration. Nanotron has demonstrated that the CSS system can be fully integrated on an IC using either SiGe or CMOS processes. 5.3 PHY-SAP Payload Bit Rate and Data Throughput Although Nanotron has demonstrated numerous data rates, Nanotron supports the 1 Mb/s which has been noted by TG4a to be a good higher data rate to allow better coexistance and lower energy consumption. John Lampe, Nanotron Technologies, GmbH

10. Selection Criteria Document Overview 5.4 Simultaneously Operating Piconets (SOP) There are numerous methods to achieve simultaneity; most significant are channelization (FDMA) and modulation/coding (CDMA). Nanotron will propose multiple channels to allow SOP in addition to its ability to use modulation/coding. 5.5 Signal Acquisition Short signal acquisition time is a strength of this proposal. Signals will be acquired within the preamble (less than 32 µS) and will automatically track from then on. John Lampe, Nanotron Technologies, GmbH

11. Selection Criteria Document Overview 5.6 System Performance Another of CSS’s strengths is system performance; it has demonstrated superior performance in multipath and interfering environments [3] 5.7 Ranging Chirp modulation has been used in radars for many years, so the ranging aspects of chirps are very well understood and documented. Nanotron is confident that CSS will provide accuracy better than the 1 meter specified in the TRD. John Lampe, Nanotron Technologies, GmbH

12. Selection Criteria Document Overview 5.8 Link Budget The regulatory environment at 2.4 GHz allows CSS to be transmitted at levels from 10 to 30 dBm to allow for very high link margins. A link margin of 103 dB will result from a device with 10 dBm transmit power using the sensitivity specified in 5.9. At 30 meters the link margin would be 33 dB. 5.9 Sensitivity Nanotron has demonstrated CSS with sensitivities of -93 dBm at 1 Mb/s validating the theoretical Eb/No calculations of 9.8 dB. John Lampe, Nanotron Technologies, GmbH

13. Selection Criteria Document Overview 5.11 Power Consumption Due to its low gate count and higher data rate the energy consumption of CSS is predicted to be better than the current 15.4 systems being deployed. 5.12 Antenna Practicality The antennas for this 2.4 GHz proposal are small yet efficient, easy to manufacture, and can be bought off the shelf as proven by the millions of antennas for 802.11x, 802.15.x, and Bluetooth devices John Lampe, Nanotron Technologies, GmbH

14. Partial listing of the Public Domain Papers on Chirp Spread Spectrum 1 A robust high speed indoor wireless communications system using chirp spread spectrum Pinkney, J.Q.; Sesay, A.B.; Nichols, S.; Behin, R.;Electrical and Computer Engineering, 1999 IEEE Canadian Conference on  ,Volume: 1 , 9-12 May 1999 2 A Robust Ultra Broadband Wireless Communication System Using SAW Chirped Delay Lines A. Springer, A. Pohl, W. Gugler, M. Huemer, L. Reindl, C. C. W. Ruppel, F.Seifert, R. Weigel • The feasibility of combating multipath interference by chirp spread spectrum techniques over Raleigh and Rician fading channels Ywh-Ren Tsai, Jin-Fu Chang 4 Gated Chirps for Signal Processing and Communication Engineering Alfred Pohl, Martin Brandl, Reinhard Steindl, Leonhard Reindl, Franz Seifert John Lampe, Nanotron Technologies, GmbH

15. Partial listing of the Public Domain Papers on Chirp Spread Spectrum 5 Bit Error Rate Probabilities of Chirp Spread Spectrum Modulation in the AWGN Channel with Overlap (pending publishment) John Pinkney, Member, IEEE, Abu Sesay, Member, IEEE. 6 A Chirp Spread Spectrum DPSK Modulator and Demodulator for a Time Shift Multiple Access Communication System by using SAW devices Yoshihiko Takeuchi and Kazuhiko Yamanouchi 7 A Chirp-Based Wideband Spread Spectrum Modulation Technique for WLAN Applications W. Gugler, A. Springer and R. Weigel 8 Fast Adaptive Interference Cancellation in Low Cost SAW Based Chirp Spread Spectrum Systems Alfred Pohl, Gerald Ostermayer, Leo Reindl, Franz Seifert, Robert Weigel John Lampe, Nanotron Technologies, GmbH