January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 1
doc.: IEEE 802. 15-05-0077-00-004a
Submission
Project: Project: IEEE 802.15 WPAN Low Rate Alternative PHY Task Group 4a (TG4a)IEEE 802.15 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:[+41 32 720 56 52], FAX: [+41 32 720 57 20], E-Mail:[[email protected]]
Re: [IEEE P802.15 LDR ALT PHY Call For Proposals]
Abstract: [This document presents a novel constant envelope LDR UWB air interface for the IEEE P802.15 ALT PHY ]
Purpose: [For information to IEEE 802.15.4a Task Group by CSEM Switzerland]
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.
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 2
doc.: IEEE 802. 15-05-0077-00-004a
Submission
FM-UWB:
A Low Complexity Low Data Rate Constant Envelope UWB Communications System for
PAN/BAN applications.
John F.M. Gerrits / John R. FarserotuWireless Communications Department
CSEM Systems EngineeringSwitzerland
http://www.csem.ch
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 3
doc.: IEEE 802. 15-05-0077-00-004a
Submission
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.
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 4
doc.: IEEE 802. 15-05-0077-00-004a
Submission
FM-UWB, How does it work?
)ff(f)(B mmRF 212
Analog frequency modulation has the unique property that the RF bandwidth BRF is not only related to the bandwidth fm 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 steepspectral roll-off. By modulating the subcarrier, data can be transmitted.
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 5
doc.: IEEE 802. 15-05-0077-00-004a
Submission
FM-UWB Transmitter
FSK FM
[1, 2]
FSK subcarrier
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 6
doc.: IEEE 802. 15-05-0077-00-004a
Submission
FM-UWB Spectrum and CoexistencePSD lowered by 10 log10(f /fSUB)
For f = 600 MHz, fSUB = 1 MHz
PSD reduced 28 dB
FM-UWB uses a high modulation index FM signal
Modulated by a low-frequency triangular signal (fSUB)
An analog spread spectrum system
Bandwidth: BRF = 2(f + fSUB)
Rapid spectralroll-off
Flat power spectral density
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 7
doc.: IEEE 802. 15-05-0077-00-004a
Submission
A multi-user system can be realized by: FDMA at sub-carrier level
FDMA at RF carrier level TDMA tecniques
FM-UWB ReceiverFSK subcarriers
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 8
doc.: IEEE 802. 15-05-0077-00-004a
Submission
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., NMAX = 15 @ 100 kbit/s, NMAX = 150 @ 1 kbit/s).
subcarrier frequency [MHz]
3 x 10 kbit/s 1 x100 kbit/s
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 9
doc.: IEEE 802. 15-05-0077-00-004a
Submission
Wideband FM Delay Line Demodulator
This demodulator has been fully integrated on silicon.
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 10
doc.: IEEE 802. 15-05-0077-00-004a
Submission
FM-UWB Performance in AWGN
Data rate R
[kbit/s]
SNRRF
[dB]
PL
[dB]
dFS
[m]
1 -22 90 183
10 -17 85 106
100 -11 79 52
1000 -5 73 25
Processing gain =
500 MHz
SUB
RF10 B
Blog10
2 R
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 11
doc.: IEEE 802. 15-05-0077-00-004a
Submission
Robustness to MB-OFDM UWB signals
BER < 1x10-6
SIR = -10 dB
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 12
doc.: IEEE 802. 15-05-0077-00-004a
Submission
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
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 13
doc.: IEEE 802. 15-05-0077-00-004a
Submission
IC Technology Requirements
A good CMOS or BiCMOS techno (fT = 100 GHz),low VT and low VDD (1 V), on-chip passives with moderate Q factor.
Tx Rx
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 14
doc.: IEEE 802. 15-05-0077-00-004a
Submission
Frequency Domain Localization
FMCW radar
c
d
t
B
c
d
t
ff
t
ff
sweep
RF
sweep
inst 22 12
1 GHz 1 m
1 s 3x108 m/s
6.67 MHz
[3, 4]
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 15
doc.: IEEE 802. 15-05-0077-00-004a
Submission
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
January, 2005
John F.M. Gerrits / John R. Farserotu, CSEMSlide 16
doc.: IEEE 802. 15-05-0077-00-004a
Submission
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. 90 - 93.
[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, 21-23 September 2004, pp. 45-56.
[4] John F.M. Gerrits, John R. Farserotu, John R. Long, "UWBFM: A Low and Medium DataRate Constant Envelope UWB Communications System with Localization Potential".MAGNET Workshop, November 11-12, Shanghai