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:[john.gerrits@csem.ch]

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