doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 1 Project: IEEE WPAN Low Rate Alternative PHY Task Group 4a (TG4a) Submission Title: [FM-UWB: A Low Complexity Low Data Rate Constant Envelope UWB Communications System ] Date Submitted: [7 January, 2005] Source: [John F.M. Gerrits] Company [CSEM] Address [Jaquet Droz 1, CH2007 Neuchatel, Switzerland] Voice:[ ], FAX: [ ], Re: [IEEE P LDR ALT PHY Call For Proposals] Abstract:[This document presents a novel constant envelope LDR UWB air interface for the IEEE P ALT PHY ] Purpose:[For information to IEEE a Task Group by CSEM Switzerland] Notice:This document has been prepared to assist the IEEE P 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 P
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 2 FM-UWB: A Low Complexity Low Data Rate Constant Envelope UWB Communications System for PAN/BAN applications. John F.M. Gerrits / John R. Farserotu Wireless Communications Department CSEM Systems Engineering Switzerland
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 3 Motivation for FM-UWB Impulse radio has proven to be a good solution for HDR UWB systems. It requires pulse synchroniation and accurate timing. We believe that it is not necessarily the best approach for a simple, low-cost, low-power, short-range, LDR communiciations system for PAN/BAN applications. Since the definition of a UWB signal does not specify a particular air interface or modulation scheme, many different techniques may be applicable to a UWB signal. More established modulation schemes may be used to generate a UWB signal.
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 4 FM-UWB, How does it work? Analog frequency modulation has the unique property that the RF bandwidth B RF is not only related to the bandwidth f m of the modulating signal, but also to the modulation index that can be chosen freely. High modulation index FM can be seen as an analog implementation of a spread spectrum system with spreading gain equal to the modulation index . The power spectral density of a wideband FM signal has the shape of the probability density function of the modulating signal (subcarrier). A triangular subcarrier signal will yield a flat RF UWB spectrum with steep spectral roll-off. By modulating the subcarrier, data can be transmitted.
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 5 FM-UWB Transmitter FSK FM [1, 2] FSK subcarrier
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 6 FM-UWB Spectrum and Coexistence PSD lowered by 10 log 10 ( f /f SUB ) For f = 600 MHz, f SUB = 1 MHz PSD reduced 28 dB FM-UWB uses a high modulation index FM signal Modulated by a low-frequency triangular signal (f SUB ) An analog spread spectrum system Bandwidth: B RF = 2( f + f SUB ) Rapid spectral roll-off Flat power spectral density
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 7 A multi-user system can be realized by: FDMA at sub-carrier level FDMA at RF carrier level TDMA tecniques FM-UWB Receiver FSK subcarriers
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 8 FDMA subcarrier techniques When the users share the same RF carrier frequency, simultaneous demodulation of multiple signals must be performed in the receiver. As in a DSSS system, the limit is multiple-access interference (e.g., N MAX = 100 kbit/s, N MAX = 1 kbit/s). subcarrier frequency [MHz] 3 x 10 kbit/s1 x100 kbit/s
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 9 Wideband FM Delay Line Demodulator This demodulator has been fully integrated on silicon.
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 10 FM-UWB Performance in AWGN Data rate R [kbit/s] SNR RF [dB] PL [dB] d FS [m] Processing gain = 500 MHz 2 R
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 11 Robustness to MB-OFDM UWB signals BER < 1x10 -6 SIR = -10 dB
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 12 Power Consumption Projections Power consumption estimates for FM-UWB (continuous): - Transmitter 2 mW, Receiver 5 mW These values can definitely compete with ISM solutions. - Lower values possible dependent on duty cycle
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 13 IC Technology Requirements A good CMOS or BiCMOS techno (f T = 100 GHz), low V T and low V DD (1 V), on-chip passives with moderate Q factor. Tx Rx
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 14 Frequency Domain Localization FMCW radar 1 GHz 1 m 1 s 3x10 8 m/s 6.67 MHz [3, 4]
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 15 FM-UWB Features Simple hardware implementation compatible with IC technology Low power consumption Relaxed hardware specs (antenna, phase noise, component tolerances) Receiver requires no local oscillator No carrier synchronization (as in impulse radio) Scalable technology Steep spectral roll-off Robustness to MB-OFDM interference and multipath CSMA techniques can enhance performance Localization compatibility
doc.: IEEE a Submission January, 2005 John F.M. Gerrits / John R. Farserotu, CSEMSlide 16 References [1]John F.M. Gerrits, John R. Farserotu, "Ultra Wide Band FM: A Constant Envelope Frequency Domain Approach",International Zurich Seminar on Communications (IZS), Feb. 18–20, 2004, Zürich, Switzerland, pp [2] John F.M. Gerrits, Michiel H.L. Kouwenhoven, Paul R. van der Meer, John R. Farserotu, John R. Long, "Principles and Limitations of UWBFM Communications Systems ", accepted by the EURASIP Journal of Applied Signal Processing [3]John F.M. Gerrits, John R. Farserotu, John R. Long, "UWB Considerations for “My Personal Global Adaptive Network” (MAGNET) Systems", Proceedings of the 30th European Solid-State Circuits Conference, ESSCIRC 2004, Leuven, Belgium, September 2004, pp [4]John F.M. Gerrits, John R. Farserotu, John R. Long, "UWBFM: A Low and Medium Data Rate Constant Envelope UWB Communications System with Localization Potential". MAGNET Workshop, November 11-12, Shanghai