“main” — 2009/4/15 — 19:09 — page 1 — #1

(1)

i

i

(2)

i

“main” — 2009/4/15 — 19:09 — page 2 — #2

i

Copyright c Francesca Zanier, 2009

Manuscript received February 29, 2009

(3)

i

“main” — 2009/4/15 — 19:09 — page i — #3

i

Abstract

Positioning accuracy in satellite navigation systems depends on time-delay estima-tion (TDE) between satellite transmitted codes and local receiver replicas. This thesis explores the fundamental limits of TDE accuracy of spread spectrum (SS) signals making use of estimation theory and signal synchronization tools, which makes the proposed analysis suitable for both navigation and communication systems and independent from receiver configurations. In particular, this contribution derives some criteria to improve positioning accuracy in the additive white Gaussian noise (multipath-free) scenario, focusing on the (satellite) transmitter side of a SS system. Four different solutions, based on the minimization of the variance of the TDE, are presented by means of signal design. The first method speculates on the shaping of the pulse format of a linearly modulated Direct Sequence (DS)-SS signal. A pulse loss parameter useful for comparing performance of different pulse signals in a dedicated receiver bandwidth is thus defined. The second approach still considers DS-SS linearly modulated signals, proposing a joint shaping pulse-spreading code optimization. A design criterion to derive an optimal spreading waveform is thus derived both theoretically and numerically. A set of non-binary band-limited (NBBL) spreading waveforms that further improve the TDE accuracy while maintaining good properties of code acquisition and interference management are thus obtained. The third solution encompasses the design of SS-Continuous Phase Modulation (SS-CPM) that allows good TDE performance while guaranteing a constant complex envelope of the signal, thus showing high robustness to non-linear distortions introduced by non-linear high power amplifier (HPA). Finally, as fourth approach, we show how a multicarrier signal can be formatted to obtain maximum estimation accuracy. Capitalizing on this, we also demonstrate that the inherent flexibility about power and frequency allocation possessed by such signal is expedient to the achievement of a cognitive localization system that adapts to the changing situation of availability

(4)

i

“main” — 2009/4/15 — 19:09 — page ii — #4

i

ii ABSTRACT

and interference of a wideband radio channel.

Performance of the proposed solutions for future GNSS systems is compared with that of existing DS-SS signals for current satellite positioning systems. Performance of some schemes is evaluated as signal options to be used in the C-band portion envisioned for GNSS evolutions. Possible countermeasures to the effects of multipath propagation are also discussed.

(5)

i

“main” — 2009/4/15 — 19:09 — page iii — #5

i

Acknowledgments

The present work has been developed during the years spent in the DSP laboratory of the Dipartimento di Ingegneria dell’Informazione of the University of Pisa, and there are special people I want to acknowledge because they were extremely important to me during the course of my thesis.

I would like to express my deepest gratitude to my advisor, Prof. Marco Luise for his excellent guidance and continual support during the course of my studies. He was essential for my interest in Research, thanks to his precious suggestions and for the continuous enthusiasm that made the work together a great experience. I really thank him for all the opportunities he offered me.

I owe my thanks to all my colleagues at the DSP lab, for their technical support and for their friendship. In particular I would like to thank Dr. Giacomo Bacci for his precious guidance and friendship, Dr. Fabio Principe, Gabriele Boccolini, Dr. Marilena Maiolo, Dr. Antonio D. Fittipaldi for their cooperation, Dr. Luca Giugno, Marco Della Maggiora and Pamela Cologna, for their valuable support and Andrea Emmanuele and Pietro Gio´e for their active cooperation.

A considerable added value to my Research has been given during my stay at ESTEC, European Space Agency (ESA). I am sincerely indebted to Dr. Riccardo De Gaudenzi and Jean-Luc Gerner for giving me the opportunity of working within the Radio Navigation working group at ESTEC and for their valuable guidance. In particular I want to thank Dr. Massimo Crisci for its outstanding supervision and patience, and all the colleagues at ESTEC that welcome me and made my staying a great experience. Most of them have become really good friends, like the big Italian community that made enjoyable my stay in the rainy Netherlands.

A big thank goes to the friends of always for offering me their warm friendship: to my women, Chiara, Anna, Silvia, Dany, Paolina, Sule, Claudia, Sere, Cami, “che donne!” and to Papotto, Raffo, Bruno, Andrea, Micky, Diego, Marco. To my universitarian

(6)

i

“main” — 2009/4/15 — 19:09 — page iv — #6

i

iv ACKNOWLEDGMENTS

friends, Balle, Sara, Silvia, Taty, Lety for being real friends.

Dulcis in fundo, my most heartfelt gratitude goes to my mum Maila and my dad Leandro for their love. I would have not reached this point in life without their support. Finally, I would like to say my lovely “grazie” to Valerio, who enriched me every day of these years. You supported me with your love and by making me smile. Grazie.

(7)

i

“main” — 2009/4/15 — 19:09 — page v — #7

i

List of Figures

1.1 User located at one of two points on shaded circle. . . 16

1.2 Use of replica code to determine satellite code transmission time . . . 17

1.3 User position vector representation . . . 18

3.1 Spectra of CBOC(6,1,1/11), BOC(6,1) and BOC(1,1). . . 60

3.2 Spectrum of BOC(15,2.5). . . 60

3.3 Band-limited Gold code spectrum. . . 70

3.4 NBBL signal spectrum. . . 70

3.5 NBBL auto-correlation function for different auto-correlation peaks. . 72

3.6 NBBL MPEE for different auto-correlation peaks. . . 73

3.7 Effects of signal and bandwidth on the main lobes of the MPEE. . . . 74

3.8 Effects of signal and bandwidth on the weighted MPEE. . . 75

3.9 Sensitivity of the weighted MPEE to τ1av. . . 75

3.10 Signal PSD. Case QBLSC( 8.5, 2 ). . . 79

3.11 Constellation plot. Case QBLSC( 8.5, 2 ). . . 79

3.12 PSD. Case QBOC(8,2). . . 81

3.13 Constellation plot. Case QBOC(8,2). . . 81

3.14 Tracking error. . . 82

3.15 Weighted multipath error envelope. . . 83

3.16 PSD after TWT. QBOC(8,2) vs QBLSC(8.5,2). . . 84

4.1 SS-CPM transmitter. . . 92

4.2 PSD of the CPM with LREC pulse. . . 97

4.3 PSD of the CPM with LRC pulse. . . 98

4.4 PSD of the CPM with LGAU pulse, L = 4. . . 98

(12)

i

“main” — 2009/4/15 — 19:09 — page x — #12

i

x LIST OF FIGURES

4.6 Square Wave (SQW) frequency pulse. . . 99

4.7 SS-CPM Receiver. . . 102

4.8 DDLL1 code tracking loop. . . 102

4.11 RMSEE for the proposed DDLL schemes. Simulation for 4GAU fre-quency pulse for h = 0.5 and h = 2.5. . . 107

4.12 S-curve function of the proposed DDLL schemes. Simulation for 4GAU frequency pulse . . . 109

4.13 Comparison of correlation functions, for h = 2.5 and h = 2.. . . 109

4.14 MPEE figures of SS-CPM as function of modulation index. . . 111

4.15 PSD of SS-CPM for Two-Rate-Service (TRS), for the I and Q branches and the total complex envelope. . . 113

4.16 MCRB of SS-CPM for Two-Rate-Service (TRS) for I-branch 1st lobe spectrum and Q-branch total spectrum, with nrepet= 3 and nrepet= 10.114 4.17 S-curve functions of SS-CPM for Two-Rate-Service (TRS), nrepet= 3, for the proposed DDLLs. . . 115

4.18 Comparison of RMSEE of SS-CPM for Two-Rate-Service (TRS) and Same-Rate-Service (SRS), nrepet= 3, for the proposed DDLLs. . . 115

5.1 Example of MC ranging signal modulator. . . 124

5.2 Example of FBMC spectrum. . . 125

5.3 Example of FBMC symmetric and asymmetric spectra. . . 127

5.4 Comparison of FBMC spectrum with monocarrier signal. . . 129

5.5 Effect of number of subcarrier, roll-off and center of gravity on the TDE fundamental limit. . . 131

5.6 Example of MC spectrum with uneven power distribution. . . 132

5.7 Example of optimal power distribution among 2 services. High and low accuracy services’ configurations. . . 136

5.8 Example of optimal power distribution in ACGN channel. . . 140

5.9 Power allocation algorithm of optimal power distribution in ACGN channel with power limitation on the subcarriers. . . 141

5.10 Example of optimal power distribution in ACGN channel with power limitation on the subcarriers. . . 142

(13)

i

“main” — 2009/4/15 — 19:09 — page xi — #13

i

LIST OF FIGURES xi

(14)

i

“main” — 2009/4/15 — 19:09 — page xii — #14

(15)

i

“main” — 2009/4/15 — 19:09 — page xiii — #15

i

List of Tables

3.1 Pulse loss Γ(sp)_{of OS signals for Galileo E1/L1 channels as a function}

of BIF. . . 61

3.2 Pulse loss Γ(sp)_{of PRS signals for Galileo E1/L1 as a function of B}

IF. 62

3.3 Average gains Γ(sw)_{of NBBL signals with respect to Gold codes. . . .} ₇₁

3.4 Summary of out-of-band emission and tracking error. . . 84

4.1 Summary of simulation results: Tc values satisfying “signal bounding

box”.

N/A stands for “Not Available”, while “-” means that “no solution was found”. . . 119

(16)

i

“main” — 2009/4/15 — 19:09 — page xiv — #16

(17)

i

“main” — 2009/4/15 — 19:09 — page xv — #17

i

List of Acronyms

ACGN additive colored Gaussian noise ACK acknowledge

ADC analog-to-digital conversion/converter AFL anchor-free localization

AGNSS assisted-GNSS

AltBOC alternate binary offset carrier AOA angle-of-arrival

AOD angle of departure

ARNS aeronautical radio navigation services A-S anti-spoofing

AS azimuth spread

AWGN additive white Gaussian noise BCH Bose-Chaudhuri-Hocquenghem BOC binary offset carrier

bps bits per second

BPSK binary phase shift keying BPZF band-pass zonal filter BS base station

(18)

i

“main” — 2009/4/15 — 19:09 — page xvi — #18

i

xvi LIST OF ACRONYMS

BSC binary symmetric channel C/A coarse/acquisition

C/NAV commercial/navigation CAP contention access period

CBOC composite binary offset carrier CC central cluster

cdf cumulative distribution function CDMA code division multiple access CFP contention free period

CH cluster head

CIR channel impulse response CL civil-long

CM civil-moderate

CNSS Compass navigation satellite system CPM continuous-phase-modulation

cps chips per second

CPS cognitive positioning system CR cognitive radio

CRB Cram´er-Rao lower bound CRC cyclic redundancy check

CS control segment/commercial service CSI channel state information

(19)

i

“main” — 2009/4/15 — 19:09 — page xvii — #19

i

LIST OF ACRONYMS xvii

DGPS differential GPS

DMLL distributed maximum log-likelihood DoD Department of Defense

DP direct path DS delay spread

DS-SS direct sequence spread spectrum EB energy-based

ED energy detector

EGNOS European geostationary navigation overlay system EIRP equivalent isotropically radiated power

EKF extended Kalman filter ERQ enhanced robust quad ESA European Space Agency EU European Union

F/NAV freely accessible navigation FCC federal communications commission FDMA frequency division multiple access FEC forward error correction

FFD full function device FIM Fisher information matrix FOC full operational capability

FPK Fl¨achen-Korrektur-Parameter (area correction parameters) GAGAN GPS aided GEO augmented navigation

(20)

i

“main” — 2009/4/15 — 19:09 — page xviii — #20

i

xviii LIST OF ACRONYMS

GANSS Galileo/Additional navigation satellite systems GB Gabor bandwidth

GDOP geometric dilution of precision GEO geostationary

GIOVE Galileo In-Orbit Validation Element GIS geographical information system

GLONASS global orbiting navigation satellite system Gen-MSK Generalized Minimum-Shift-Keying GNSS global navigation satellite system GNSSs global navigation satellite systems GPRS general packet radio service GPS global positioning system HEO highly-inclined elliptical orbits HOW handover word

HPA high power amplifier I in-phase

i.i.d. independent, identically distributed I/NAV integrity/navigation

ICD interface control document

ICT information and communication technologies IE informative element

IF intermediated frequency

(21)

i

“main” — 2009/4/15 — 19:09 — page xix — #21

i

LIST OF ACRONYMS xix

ILS instrument landing system

IRNSS regional navigation satellite system IR-UWB impulse radio UWB

ISM industrial scientific medical

ISRO Indian space research organization IST information society technologies

ITU International Telecommunication Union JBSF jump back and search forward

KF Kalman filter

LAAS local area augmentation system LCS location services

LDPC low density parity check LLC logical link control LOS line-of-sight LS least squares

MAC medium access control

MBOC multiplexed binary offset carrier MB-UWB multi-band UWB

MCRB Modified Cram´er-Rao lower bound MEO medium earth orbit

MF matched filter

MIMO multiple-input multiple-output MISO multiple-input single-output

(22)

i

“main” — 2009/4/15 — 19:09 — page xx — #22

i

xx LIST OF ACRONYMS

ML maximum likelihood

MMSE minimum mean squared error MP multipath

MPEE multipath error envelope MRC maximal ratio combining MS mobile station

MSAS multi-functional satellite augmentation system MSB most significant bit

MSE mean squared error

MSEE mean squared estimation error MSK Minimum-Shift-Keying

MST minimum spanning tree

MTSAT multi-functional transport satellite MUI multi-user interference

N/A not available NAV navigation

NAVSTAR navigation system for timing and ranging NB narrowband

NBI narrowband interference NLOS non-line-of-sight NN neural network

NQRT new quad robustness test NRZ non-return to zero

(23)

i

“main” — 2009/4/15 — 19:09 — page xxi — #23

i

LIST OF ACRONYMS xxi

NSI5 non-standard I5 NSQ5 non-standard Q5 NTP network time protocol OCS operational control segment OMA open mobile alliance OMUX output multiplexer OOB out of band

OQPSK Offset Quadrature Phase-Shift Keying OQRT original quad robustness test

ORQ original robust quad OS open service

OTDOA observed TDOA

PAM pulse amplitude modulation PAN personal area network pdf probability density function PDP power delay profile PF particle filter

PFD power flux density PHY physical layer

POC payload operation center POCS projections onto convex sets PN pseudo-noise

(24)

i

“main” — 2009/4/15 — 19:09 — page xxii — #24

i

xxii LIST OF ACRONYMS

PPS precise position service PRN pseudo-random noise PRS public regulated service PRT partial robustness test PSD power spectral density PSDP power spatial delay profile PSK phase shift keying

PVT position, velocity, and time Q quadrature-phase

QZSS quasi-zenith satellite system

RDSS radio determination satellite service RF radio frequency

RFD reduced function device RFID radio frequency identification

RIMS ranging and integrity monitoring stations RLE robust location estimation

RMS root mean square RMSE root mean square error

RMSEE root mean square error estimation RNSS regional navigation satellite system RQ robust quadrilateral

RRC root raised cosine/radio resource control RRLP radius resource location protocol

(25)

i

“main” — 2009/4/15 — 19:09 — page xxiii — #25

i

LIST OF ACRONYMS xxiii

RSS received signal strength RT robust trilateration

RTCM radio technical commission for maritime services RTK real-time kinematic

r.v. random variable SA selective availability SAR search and rescue

SBAS satellite-based augmentation system SBS serial backward search

SBSMC serial backward search for multiple clusters SDS symmetric double sided

SET SUPL enabled terminal SLP SUPL location platform SIMO single-input multiple-output SIS signal-in-space

SISO single-input single-output SoL safety-of-life

SMC sequential Monte Carlo SNR signal-to-noise ratio

SNIR signal-to-noise-plus-interference ratio sps symbols per second

SPS standard position service SRS same-rate-service

(26)

i

“main” — 2009/4/15 — 19:09 — page xxiv — #26

i

xxiv LIST OF ACRONYMS

SS spread spectrum

SS-CPM spread spectrum continuous-phase-modulated

SS-GenMSK Spread-Spectrum Generalized-Minimum-Shift-Keying ST simple thresholding

SUPL secure user-plane location SV satellite vehicle

TDE time delay estimation TDOA time difference-of-arrival TI trilateration intersection TLM telemetry

TMBOC time-multiplexed binary offset carrier TOA time-of-arrival TOF time-of-flight TH time-hopping TNR normalized threshold TTFF time-to-first-fix TRS two-rate-service TW-TOA two-way-TOA

TWTA traveling wave tube amplifier U.S. United States

UE user equipmment

UKF unscented Kalman filter ULP user location protocol

(27)

i

“main” — 2009/4/15 — 19:09 — page xxv — #27

i

LIST OF ACRONYMS xxv

UMTS universal mobile telecommunications system URE user range error

US user segment

UT user terminal

UTC coordinated universal time

UTRA UMTS terrestrial radio access UWB ultra-wide band

VANET vehicular ad-hoc network

VRS virtual reference station

WAAS wide area augmentation system WADGPS wide area differential GPS

WARN wide area reference network WB wideband

WiMAX worldwide interoperability for microwave access WLAN wireless local area network

WLS weighted least squares

WPAN wireless personal area network wrt with respect to

WSN wireless sensor network

WWB Weiss-Weinstein bound ZZB Ziv-Zakai lower bound

(28)

i

“main” — 2009/4/15 — 19:09 — page xxvi — #28

(29)

i

“main” — 2009/4/15 — 19:09 — page xxvii — #29

i

List of Publications

International Journals

1. “Spectrally Compatible Iterative Water Filling”, J. Verlinden, E. Van den Bo-gaert, T. Bostoen, F. Zanier, M. Luise, EURASIP Journal on Applied Signal Proc., Vol. 2006, Article ID 58380, Pages 1-10.

2. “Enhanced-Accuracy, Low-Complexity Doppler-Shift and Doppler-Rate Esti-mators in Packet Transmission”, L. Giugno, F. Zanier, M. Luise , EURASIP Journal on Wireless Communication and Networking, Special Issue on Sat Comm., Vol. 2007, Article ID 29086, 12 pages, 2007.

3. “Criteria to Improve Time-Delay Estimation of Spread Spectrum Signals in Satellite Positioning”, F. Zanier, G. Bacci, M. Luise , Submitted to IEEE Journal of selected topics in signal processing, Special Issue on Advanced Signal Processing for GNSS and Robust Navigation.

4. “SS-CPM signal analysis with application to positioning systems”, F. Zanier, A.Emmanuele, G.Boccolini, M. Luise , To be Submitted to Aerospace and Electronic systems.

International Conferences

5. “Signal-in-Space Design Criteria for Next-Generation Satellite Positioning”, G. Bacci, M. Luise, F. Zanier, Proc. of the 9th International Workshop on Signal Processing for Space Communications (SPSC), Noordwijk, The Netherlands, 11-13 September, 2006.

(30)

i

“main” — 2009/4/15 — 19:09 — page xxviii — #30

i

xxviii LIST OF PUBLICATIONS

6. “Optimal Burst Format for Joint Doppler-Shift and Doppler-Rate Estimation in Packet Transmission”, L. Giugno, M. Luise, F. Zanier, Proc. of the NEWCOM-ACoRN Joint Workshop, Vienna, Austria, Sept. 2006.

7. “Nonbinary Bandlimited Signature Waveforms for Spread Spectrum Signals with Application to Satellite Positioning”, F. Zanier, G. Bacci, M. Luise, Proc. of the 3rd ESA Workshop on Satellite Navigation User Equipment Technologies - NAVITEC 2006, Noordwijk, The Netherlands, 11-13 December, 2006.

8. “Non-Binary Spread Spectrum Signals with Good Delay-Tracking Features for Satellite Positioning”, F. Zanier, G. Bacci, M. Luise, Best student paper of 3rd Int. Waveform Diversity & Design Conference (WDD), Pisa, Italy, Jun. 2007.

9. “Optimal Pilot Symbol Distribution for Efficient and Low-Complexity Doppler-Shift and Doppler-Rate Estimation in Bursty Transmission”, L. Giugno, F. Zanier, M. Luise, Proc. of the Int. IEEE conference on Communications (ICC) 2007, Glasgow, Scotland, 24-28 June 2007.

10. “Signal design criteria and parametric analysis for next generation C-band satel-lite navigation system”, F. Zanier, M. Crisci, M. Luise, Proc. of the European Navigation Conference (ENC-GNSS), Toulouse, France, April 2008.

11. “Multipath resistance for non-binary DS/SS signals with good delay-tracking features for satellite positioning”, F. Zanier, G. Bacci, M. Luise, M. Crisci, Proc. of the European Navigation Conference (ENC-GNSS), Toulouse, France, April 2008.

12. ”Assessment of the Feasibility of GNSS in C-Band”, E. Colzi, G. Lopez-Risueno, J. Samson, P. Angeletti, M. Crisci, R. De Gaudenzi, J.-L. Gerner, F. Zanier and M. Luise, Proc. of the AIAA Int. Commun. Satellite Systems Conf. (ICSSC), San Diego, CA, June 2008.

13. “Fundamental Issues in Time-Delay Estimation of Multicarrier Signals with applications to Next-Generation GNSS”, F. Zanier, M. Luise, Proc. of the 10th International Workshop on Signal Processing for Space Communications (SPSC), Rhodes Island, Greece, Oct. 2008.

(31)

i

“main” — 2009/4/15 — 19:09 — page xxix — #31

i

LIST OF PUBLICATIONS xxix

14. “Continuous-Phase Modulated Signals for Satellite Positioning in the C-Band”, F. Zanier, A. Emmanuele, G. Boccolini, M. Luise, Proc. of the 4th ESA Workshop on Satellite Navigation User Equipment Technologies (NAVITEC), Noordwijk, The Netherlands, Dec. 2008.

15. “A new look into the issue of the Cramr-Rao bound for delay estimation of digitally modulated signals”, F. Zanier, M. Luise, IEEE Int. Conf. on Acustic Speech and Signal Processing (ICASSP), Taipei, Taiwan, April 2009.

16. “Multicarrier Signals: a Natural Enabler for Cognitive Positioning Systems”, M.Luise, F.Zanier, in Proc. of 7th International Workshop on Multi-Carrier Systems & Solutions MC-SS 2009, Herrsching, Germany, May 05-06, 2009.

17. “Constant-Envelope Signal-in-Space Design for GNSSs in the C-band”, A.Emmanuele, F.Zanier, G.Boccolini, M.Luise, In Proc. of European Navigation Conference - Global Navigation Satellite Systems (ENC-GNSS) 2009, Napoli, Italy, May 2009.

Other works

18. “Input to the C-band study. Contribution to the signal definition”, F. Zanier, M. Crisci, ESA internal report, TEC-ETN, Sep.2007.

19. “Sub-Cramr-Rao Estimation and Cognitive Positioning” M.Luise, F.Zanier, 5th Joint Workshop on Communications and Coding (JWCC08), 2008.

20. Applications and Methods of Waveform Diversity, SciTech Publishing, Inc. Editors: Drs. Amuso, Blunt, Mokole, Schneible and Wicks. The text book includes our paper, entitled, “Non-Binary Spread Spectrum Signals with Good Delay-Tracking Features for Satellite Positioning”, in Chapter C-V-12. To be published in Feb 2009.

21. “Signal design criteria and parametric analysis for next generation C-band satel-lite navigation system”, F. Zanier, M. Crisci, M. Luise, Coordinates Magazine, 2009.

(32)

i

“main” — 2009/4/15 — 19:09 — page xxx — #32

“main” — 2009/4/15 — 19:09 — page 1 — #1

Abstract

Acknowledgments

Contents

List of Figures

List of Tables

List of Acronyms

List of Publications

International Journals

International Conferences

Other works