Signal Processing - September 2017 - 51

in the literature, some of the best tradeoffs between these
various metrics are provided by the BJ, DET, and codesmoothing approaches. A joint optimum tracking metric
is, however, yet to be found. An extensive comparison of
27 ambiguous and unambiguous approaches has been conducted, with few selected performance examples in terms of
detection probabilities in acquisition, standard error deviation in code tracking, false lock threat mitigation, and multipath error envelopes.
This article presented an overview of one of today's
important GNSS signal processing challenges and aimed
at offering and attractive and stimulating starting point for
further studies regarding the design of techniques for processing BOC signals, and especially high-order BOC signals, which are the most challenging. For future research
directions, performance with more realistic channel models, such as the ITU-R channel models [9] or ray-tracing
channel models, can be investigated to better understand the
limitations of each unambiguous algorithm under a certain
target scenario.

Acknowledgments
This work was supported by the Academy of Finland (project
303576) and partly performed under a contract of the European Space Agency in the frame of the Announcement of
Opportunities on GNSS Science and Innovative Technology
within the European GNSS Evolutions Programme. The
views presented in the article solely represent the opinion of
the authors. The work of G. Seco-Granados and J.A. LópezSalcedo was partly supported by R&D Project of Spanish
Ministry of Economy and Competitiveness under grant
TEC2014-53656-R.

Authors
Elena Simona Lohan (elena-simona.lohan@tut.fi) received
her M.Sc. degree from Polytechnics University of Bucharest
in 1997, a DEA degree from Ecole Polytechnique, Paris,
France, in 1998, and a Ph.D. degree from Tampere
University of Technology (TUT), Finland, in 2003. She is
now an associate professor at TUT and a visiting professor
at Universitat Autonoma de Barcelona, Spain. She is a coeditor of Galileo Positioning Technology (Springer) and a
coeditor of a recently published Springer book MultiTechnology Positioning. She has coauthored more than 160
international publications. Her current research interests
include wireless location techniques, location-based services, and privacy-aware positioning solutions. She is a Senior
Member of the IEEE.
Diego Alonso de Diego (diego.alonso@tut.fi) received
his M.Sc. degree in telecommunication engineering from the
Technical University of Madrid, Spain, in 2016. He recently
joined Airbus Defense & Space as a digital processor systems engineer within the Communication Products group,
based in Stevenage, United Kingdom. Previously, he worked
in the Signal Processing for Wireless Positioning group
where he was involved in an European Space Agency-funded

research Galileo project. This group belongs to the Department of Electronics and Communications Engineering at the
Tampere University of Technology, Finland. His research interests include satellite and mobile communication systems,
acquisition and tracking techniques, interference mitigation,
and unmanned air vehicles.
José A. López-Salcedo (jose.salcedo@uab.es) received
received his M.Sc. and Ph.D degrees in telecommunication
engineering from the Universitat Politècnica de Catalunya in
2001 and 2007, respectively. In 2006, he joined the Department of Telecommunications and Systems Engineering at the
Universitat Autónoma de Barcelona, Spain, where he is an
associate professor. He has been the principal investigator of
more than ten research projects, most of them funded by the
European Space Agency. He has held several visiting appointments at the Coordinated Science Laboratory, University of
Illinois Urbana-Champaign, the University of California,
Irvine, and the European Commission, Joint Research Centre.
His research interests lie in the field of signal processing for
communications and navigation.
Gonzalo Seco -Granados (gonzalo.seco@uab.es)
received his M.Sc. and Ph.D degrees in telecommunication
engineering from the Universitat Politècnica de Catalunya,
Spain, in 1996 and 2000, respectively, and his M.B.A. degree
from IESE Business School, Barcelona, Spain, in 2002. Until
2005, he was with the European Space Agency, where he
was involved in the design of the Galileo system. Since 2006,
he has been an associate professor with the Department of
Telecommunications, Universitat Autnoma de Barcelona,
Spain. In 2015, he was a Fulbright Visiting Scholar with the
University of California, Irvine. His research interests
include the design of signals and reception techniques for
satellite and terrestrial localization systems, multiantenna
receivers, and positioning with fifth-generation technologies.
He is a Senior Member of the IEEE.
Pedro Boto (pedro.boto@gmv.com) received his M.Sc.
degree in aerospace engineering from Instituto Superior Técnico,
Lisbon, Portugal, in 2014. Since joining GMV in 2014, he has
been involved in several projects related with global navigation
satellite system receiver design and development, specifically on
signal processing techniques for acquisition and tracking stages.
This work covered topics like nominal and enhanced carrier
tracking techniques applicable to ionosphere scintillation tracking, high-sensitivity acquisition and tracking, and higher-order
binary offset carrier modulations processing under harsh scenarios for low C/N 0 conditions typical of urban environments.
Pedro Fernandes (pedro.fernandes@gmv.com) received
his B.Sc. degree in electronics and telecommunications and
computers engineering from Instituto Superior de Engenharia
de Lisboa, Portugal, in 2007, and a postgraduate degree in
open-source software from ISCTE-Instituto Universitário de
Lisboa, Portugal, in 2012. He joined GMV in 2007 and has
since been involved in operational projects like the Orbitography and Synchronization Processing Facility/Integrity Processing Facility ground control segment element under the Galileo
program and on the development of the support platform for

IEEE SIGNAL PROCESSING MAGAZINE

September 2017

http://www.M.Sc http://www.M.Sc http://www.M.Sc http://www.M.Sc http://www.B.Sc http://www.M.Sc

Table of Contents for the Digital Edition of Signal Processing - September 2017