Carles Fernández-Prades - Profile on Academia.edu (original) (raw)
Papers by Carles Fernández-Prades
Sensors, Jun 17, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Enhancing GNSS receiver performance with software-defined vector carrier tracking for rocket launching
Results in Engineering
A particle filter tracking algorithm for GNSS synchronization using Laplace’s method
SAM-P3. 4: Robust Space-Time Beamforming in GNSS by Means of Second-Order Cone Programming
216715 NEWCOM Deliverable Number: DB. 2 Progress Report I on Advanced Localization and Positioning Techniques: Fundamental Techniques and Theoretical Limits
Abstract: Theoretical limits play a fundamental role in position estimation as guidelines and ben... more Abstract: Theoretical limits play a fundamental role in position estimation as guidelines and benchmarks of new developed algorithms. When designing practical positioning techniques the main focus is on reducing the gap between theoretical and real performance and keeping the complexity of the estimator at reasonable level. This report presents the results related to position estimation techniques obtained in the first eighteen months of activity of NEWCOM++ WPR. B. Most of the material represents the outcome of joint activities ...
Proceedings of the 30th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2017), Nov 3, 2017
holds the position of Senior Researcher at the Statistical Inference for Communications and Posit... more holds the position of Senior Researcher at the Statistical Inference for Communications and Positioning (SI) Department at CTTC. He received the MSc degree in Telecommunication Engineering from La Salle University in 2004, and the PhD from UPC in 2012. His primary areas of interest include statistical signal processing, GNSS synchronization, detection and estimation theory, software defined receivers, FPGA prototyping and the design of RF front-ends. He is the recipient of the 2015 EURASIP Best PhD Thesis Award. Mr. Antonio Ramos de Torres is a Ph.D Candidate in the Signal Theory and Communications Department of the Universitat Politècnica de Catalunya (UPC). He received the MSc degree in Telecommunication Engineering from UPC in 2013. His primary areas of interest include statistical signal processing with application in spectroscopy analysis techniques and GNSS software defined receivers.
A Receiver-Independent GNSS Smart Antenna for Simultaneous Jamming and Spoofing Protection
The presence of unintentional or intentional Radio Frequency Interference (RFI) signals in the Gl... more The presence of unintentional or intentional Radio Frequency Interference (RFI) signals in the Global Navigation Satellite Systems (GNSS) frequency bands is by far one of the main vulnerabilities of every GNSS receiver. This known threat can cause severe positioning performance degradation and even a complete service unavailability. Complementary to time and frequency-domain mitigation techniques, it is well known that antenna-array based receivers can benefit from spatial domain processing. By exploiting spatial diversity, an array-based smart antenna can selectively attenuate the RFIs Direction of Arrival (DOA) and provide high gain towards the legitimate GNSS signals. In this work, we propose a receiverindependent GNSS smart antenna architecture that implements a real-time automatic and autonomous null-steering spatial filtering for GNSS bands. The platform uses Commercial Off The Shelf (COTS) components including a multichannel receiver frontend, a System on Chip (SoC) hybrid FPGA/CPU digital signal processor, and an up-converter to shift the spatially filtered GNSS signal back to its carrier frequency. In this way, the proposed smart antenna can be connected to any conventional singleantenna GNSS receiver. The paper includes both the theory of operation, the implementation details, and the prototype performance in a real-life open field scenario.
Zenodo (CERN European Organization for Nuclear Research), Nov 25, 2017
He received the PhD degree in Electrical Engineering from Grenoble INP (INPG), France, in 2010. H... more He received the PhD degree in Electrical Engineering from Grenoble INP (INPG), France, in 2010. His primary areas of interest include statistical signal processing, estimation and detection theory, robustness and adaptive methods; with applications to positioning systems and wireless communications. Dr. Carles Fernández-Prades holds the position of Senior Researcher and serves as Head of the SI Dept. at CTTC. He received a PhD degree in Electrical Engineering from Universitat Politècnica de Catalunya (UPC) in 2006, Barcelona, Spain. His primary areas of interest include statistical and multi-sensor signal processing, estimation and detection theory, and Bayesian filtering, with applications to communication systems, GNSS and software-defined radio technology.
This article presents a new multiple statepartitioning solution to the Bayesian smoothing problem... more This article presents a new multiple statepartitioning solution to the Bayesian smoothing problem in nonlinear high-dimensional Gaussian systems. The key idea is to partition the original state into several low-dimensional subspaces, and apply an individual smoother to each of them. The main goal is to reduce the state dimension each filter has to explore, to reduce the curse of dimensionality and eventual loss of accuracy. We provide the theoretical multiple smoothing formulation and a new nested sigma-point approximation to the resulting smoothing solution. The performance of the new approach is shown for the 40-dimensional Lorenz model.
This paper reports the design, proof-of-concept implementation and preliminary performance assess... more This paper reports the design, proof-of-concept implementation and preliminary performance assessment of a lowcost, real-time, portable, low power, and small form factor GNSS rebroadcaster. This device can be used both as a GNSS signal generator and as a GNSS signal regenerator. This device can be used to test the addition of new features in GNSS signals, such as new signals for ranging, and to characterize the performance of new and existing spoofing countermeasures for GNSS receivers in real time. This device does not require the use of post-processed GNSS signals, enabling the testing with live signals, for instance in a vehicular test campaign replicating the correct dynamic and channel impairments.
Direct Position Estimation Approach: How Good Can it Get?
Particle Filtering Strategies for Efficient Multipath Mitigation
Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008), Sep 19, 2008
This paper deals with the problem of multipath mitigation using a Particle Filtering (PF) approac... more This paper deals with the problem of multipath mitigation using a Particle Filtering (PF) approach. We describe two PF algorithms already proposed by the authors in [1] and [2]. The aim of the present paper is to compare both alternatives in terms of particle efficiency, that is, to study the required number of particles to achieve a certain tracking precision. The efficiency issue is of high importance when a PF implementation is envisaged since reducing the number of samples has a direct impact in the required computational resources.
GNSS Software Defined Radio: History, Current Developments, and Standardization Efforts
ION GNSS+, The International Technical Meeting of the Satellite Division of The Institute of Navigation
Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018)
This paper presents an enhancement of the well-known GNSS/INS sensor fusion approach by supportin... more This paper presents an enhancement of the well-known GNSS/INS sensor fusion approach by supporting cooperative distance measurements to improve its positioning performance for terrestrial vehicle navigation. The areas of improvement are those where the GNSS signals are severely degraded and the low-cost INS system can not provide reliable dead reckoning position estimations. In the proposed cooperative positioning scheme, additional information is acquired from other infrastructure or communication network, such as adhoc sensor network with several intercommunicated vehicles or nodes. The additional information provided mainly by distance measurements between nodes and from nodes to other elements of the network (e.g. anchor nodes placed on fixed equipment such as traffic lights) can be used as independent measurements reporting new information to the Bayesian filter. The implementation has been tested in a representative field test by deploying a network of commercial off-the-shelf Ultra Wide Band (UWB) anchor nodes, which can provide down to centimeter distance measurement accuracy. Results show an improvement of the positioning performance in challenging scenarios where the original GNSS/INS fusion did not meet ITS positioning requirements due to the GNSS signal impairments and the lack of stability of low-cost IMUs.
Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018)
He received the M.S. degree in Electrical Engineering from the Polytechnic 3University of Catalon... more He received the M.S. degree in Electrical Engineering from the Polytechnic 3University of Catalonia (UPC) in 1998. In 1999 he worked in the Signal Theory and Communications department in the Polytechnic University of Catalonia, where he was involved in DSP programming for mobile communications. From 1999 to 2006 he worked in the Cochlear Technology Centre in Belgium, where he implemented signal processing strategies for cochlear implants on DSPs. Since 2007 he is working at CTTC, implementing signal processing strategies on DSPs and FPGAs for telecommunication applications. Dr. Carles Fernández-Prades holds a position of Senior Researcher and currently serves as Head of the Statistical Inference for Communications and Positioning (SICP) Department at CTTC. He received a PhD degree in Electrical Engineering from Universitat Politècnica de Catalunya (UPC) in 2006, Barcelona, Spain. His primary areas of interest include statistical and multi-sensor signal processing, estimation and detection theory, and Bayesian filtering, with applications to communication systems, GNSS and software-defined radio technology. Dr. Javier Arribas holds a position of Senior Researcher at the SICP Department at CTTC. He received the MSc degree in Telecommunication Engineering from La Salle University in 2004, and the PhD from UPC in 2012. His primary areas of interest include statistical signal processing, GNSS synchronization, detection and estimation theory, software defined receivers, FPGA prototyping and the design of RF front-ends. He is the recipient of the 2015 EURASIP Best PhD Thesis Award.
2022 10th Workshop on Satellite Navigation Technology (NAVITEC)
This paper reports the design, proof-of-concept implementation and preliminary performance assess... more This paper reports the design, proof-of-concept implementation and preliminary performance assessment of a lowcost, real-time, portable, low power, and small form factor GNSS rebroadcaster. This device can be used both as a GNSS signal generator and as a GNSS signal regenerator. This device can be used to test the addition of new features in GNSS signals, such as new signals for ranging, and to characterize the performance of new and existing spoofing countermeasures for GNSS receivers in real time. This device does not require the use of post-processed GNSS signals, enabling the testing with live signals, for instance in a vehicular test campaign replicating the correct dynamic and channel impairments.
Gestalt: A Testbed For Experimentation And Validation Of Gnss Software Receivers
This paper presents a new platform for the experimentation with GNSS signals. It includes a set o... more This paper presents a new platform for the experimentation with GNSS signals. It includes a set of commercial of-the-shelf hardware and an open source software, constituting a state-of-the-art platform for research and development of next-generation GNSS receivers. The core of the platform is the GNSS-SDR receiver which has been extended to support multi-band and multi-system operations. As a relevant case of use to validate the research facility, we presented a triple band GNSS-SDR customization capable of receiving four GNSS signals in real-time: GPS L1 C/A, GPS L2CM, Galileo E1b, and Galileo E5a. In addition, we provided detailed descriptions of the receiver architecture, identifying the synchronization challenges of the multi-system satellite channels and providing practical and reproducible solutions. The source code developed to produce this paper has been released under the General Public License, and it is freely available on the Internet.
Fastening Gps And Galileo Tight With A Software Reciever
This paper presents the design, implementation and performance analysis of a hybrid GPS/Galileo s... more This paper presents the design, implementation and performance analysis of a hybrid GPS/Galileo software receiver. The proposed approach exploits the dissemination of Galileo-to-GPS time conversion parameters through Galileo's navigation message to mix pseudoranges of both constellations seamlessly, obtaining position fixes even with four satellites belonging to different systems. The approach is tested both with synthetically generated signals and with real-life signals using the four In-Orbit Validation Galileo satellites. The source code developed to produce this paper has been released under the General Public License, and it is freely available on the Internet.
Sensors, Jun 17, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Enhancing GNSS receiver performance with software-defined vector carrier tracking for rocket launching
Results in Engineering
A particle filter tracking algorithm for GNSS synchronization using Laplace’s method
SAM-P3. 4: Robust Space-Time Beamforming in GNSS by Means of Second-Order Cone Programming
216715 NEWCOM Deliverable Number: DB. 2 Progress Report I on Advanced Localization and Positioning Techniques: Fundamental Techniques and Theoretical Limits
Abstract: Theoretical limits play a fundamental role in position estimation as guidelines and ben... more Abstract: Theoretical limits play a fundamental role in position estimation as guidelines and benchmarks of new developed algorithms. When designing practical positioning techniques the main focus is on reducing the gap between theoretical and real performance and keeping the complexity of the estimator at reasonable level. This report presents the results related to position estimation techniques obtained in the first eighteen months of activity of NEWCOM++ WPR. B. Most of the material represents the outcome of joint activities ...
Proceedings of the 30th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2017), Nov 3, 2017
holds the position of Senior Researcher at the Statistical Inference for Communications and Posit... more holds the position of Senior Researcher at the Statistical Inference for Communications and Positioning (SI) Department at CTTC. He received the MSc degree in Telecommunication Engineering from La Salle University in 2004, and the PhD from UPC in 2012. His primary areas of interest include statistical signal processing, GNSS synchronization, detection and estimation theory, software defined receivers, FPGA prototyping and the design of RF front-ends. He is the recipient of the 2015 EURASIP Best PhD Thesis Award. Mr. Antonio Ramos de Torres is a Ph.D Candidate in the Signal Theory and Communications Department of the Universitat Politècnica de Catalunya (UPC). He received the MSc degree in Telecommunication Engineering from UPC in 2013. His primary areas of interest include statistical signal processing with application in spectroscopy analysis techniques and GNSS software defined receivers.
A Receiver-Independent GNSS Smart Antenna for Simultaneous Jamming and Spoofing Protection
The presence of unintentional or intentional Radio Frequency Interference (RFI) signals in the Gl... more The presence of unintentional or intentional Radio Frequency Interference (RFI) signals in the Global Navigation Satellite Systems (GNSS) frequency bands is by far one of the main vulnerabilities of every GNSS receiver. This known threat can cause severe positioning performance degradation and even a complete service unavailability. Complementary to time and frequency-domain mitigation techniques, it is well known that antenna-array based receivers can benefit from spatial domain processing. By exploiting spatial diversity, an array-based smart antenna can selectively attenuate the RFIs Direction of Arrival (DOA) and provide high gain towards the legitimate GNSS signals. In this work, we propose a receiverindependent GNSS smart antenna architecture that implements a real-time automatic and autonomous null-steering spatial filtering for GNSS bands. The platform uses Commercial Off The Shelf (COTS) components including a multichannel receiver frontend, a System on Chip (SoC) hybrid FPGA/CPU digital signal processor, and an up-converter to shift the spatially filtered GNSS signal back to its carrier frequency. In this way, the proposed smart antenna can be connected to any conventional singleantenna GNSS receiver. The paper includes both the theory of operation, the implementation details, and the prototype performance in a real-life open field scenario.
Zenodo (CERN European Organization for Nuclear Research), Nov 25, 2017
He received the PhD degree in Electrical Engineering from Grenoble INP (INPG), France, in 2010. H... more He received the PhD degree in Electrical Engineering from Grenoble INP (INPG), France, in 2010. His primary areas of interest include statistical signal processing, estimation and detection theory, robustness and adaptive methods; with applications to positioning systems and wireless communications. Dr. Carles Fernández-Prades holds the position of Senior Researcher and serves as Head of the SI Dept. at CTTC. He received a PhD degree in Electrical Engineering from Universitat Politècnica de Catalunya (UPC) in 2006, Barcelona, Spain. His primary areas of interest include statistical and multi-sensor signal processing, estimation and detection theory, and Bayesian filtering, with applications to communication systems, GNSS and software-defined radio technology.
This article presents a new multiple statepartitioning solution to the Bayesian smoothing problem... more This article presents a new multiple statepartitioning solution to the Bayesian smoothing problem in nonlinear high-dimensional Gaussian systems. The key idea is to partition the original state into several low-dimensional subspaces, and apply an individual smoother to each of them. The main goal is to reduce the state dimension each filter has to explore, to reduce the curse of dimensionality and eventual loss of accuracy. We provide the theoretical multiple smoothing formulation and a new nested sigma-point approximation to the resulting smoothing solution. The performance of the new approach is shown for the 40-dimensional Lorenz model.
This paper reports the design, proof-of-concept implementation and preliminary performance assess... more This paper reports the design, proof-of-concept implementation and preliminary performance assessment of a lowcost, real-time, portable, low power, and small form factor GNSS rebroadcaster. This device can be used both as a GNSS signal generator and as a GNSS signal regenerator. This device can be used to test the addition of new features in GNSS signals, such as new signals for ranging, and to characterize the performance of new and existing spoofing countermeasures for GNSS receivers in real time. This device does not require the use of post-processed GNSS signals, enabling the testing with live signals, for instance in a vehicular test campaign replicating the correct dynamic and channel impairments.
Direct Position Estimation Approach: How Good Can it Get?
Particle Filtering Strategies for Efficient Multipath Mitigation
Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008), Sep 19, 2008
This paper deals with the problem of multipath mitigation using a Particle Filtering (PF) approac... more This paper deals with the problem of multipath mitigation using a Particle Filtering (PF) approach. We describe two PF algorithms already proposed by the authors in [1] and [2]. The aim of the present paper is to compare both alternatives in terms of particle efficiency, that is, to study the required number of particles to achieve a certain tracking precision. The efficiency issue is of high importance when a PF implementation is envisaged since reducing the number of samples has a direct impact in the required computational resources.
GNSS Software Defined Radio: History, Current Developments, and Standardization Efforts
ION GNSS+, The International Technical Meeting of the Satellite Division of The Institute of Navigation
Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018)
This paper presents an enhancement of the well-known GNSS/INS sensor fusion approach by supportin... more This paper presents an enhancement of the well-known GNSS/INS sensor fusion approach by supporting cooperative distance measurements to improve its positioning performance for terrestrial vehicle navigation. The areas of improvement are those where the GNSS signals are severely degraded and the low-cost INS system can not provide reliable dead reckoning position estimations. In the proposed cooperative positioning scheme, additional information is acquired from other infrastructure or communication network, such as adhoc sensor network with several intercommunicated vehicles or nodes. The additional information provided mainly by distance measurements between nodes and from nodes to other elements of the network (e.g. anchor nodes placed on fixed equipment such as traffic lights) can be used as independent measurements reporting new information to the Bayesian filter. The implementation has been tested in a representative field test by deploying a network of commercial off-the-shelf Ultra Wide Band (UWB) anchor nodes, which can provide down to centimeter distance measurement accuracy. Results show an improvement of the positioning performance in challenging scenarios where the original GNSS/INS fusion did not meet ITS positioning requirements due to the GNSS signal impairments and the lack of stability of low-cost IMUs.
Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018)
He received the M.S. degree in Electrical Engineering from the Polytechnic 3University of Catalon... more He received the M.S. degree in Electrical Engineering from the Polytechnic 3University of Catalonia (UPC) in 1998. In 1999 he worked in the Signal Theory and Communications department in the Polytechnic University of Catalonia, where he was involved in DSP programming for mobile communications. From 1999 to 2006 he worked in the Cochlear Technology Centre in Belgium, where he implemented signal processing strategies for cochlear implants on DSPs. Since 2007 he is working at CTTC, implementing signal processing strategies on DSPs and FPGAs for telecommunication applications. Dr. Carles Fernández-Prades holds a position of Senior Researcher and currently serves as Head of the Statistical Inference for Communications and Positioning (SICP) Department at CTTC. He received a PhD degree in Electrical Engineering from Universitat Politècnica de Catalunya (UPC) in 2006, Barcelona, Spain. His primary areas of interest include statistical and multi-sensor signal processing, estimation and detection theory, and Bayesian filtering, with applications to communication systems, GNSS and software-defined radio technology. Dr. Javier Arribas holds a position of Senior Researcher at the SICP Department at CTTC. He received the MSc degree in Telecommunication Engineering from La Salle University in 2004, and the PhD from UPC in 2012. His primary areas of interest include statistical signal processing, GNSS synchronization, detection and estimation theory, software defined receivers, FPGA prototyping and the design of RF front-ends. He is the recipient of the 2015 EURASIP Best PhD Thesis Award.
2022 10th Workshop on Satellite Navigation Technology (NAVITEC)
This paper reports the design, proof-of-concept implementation and preliminary performance assess... more This paper reports the design, proof-of-concept implementation and preliminary performance assessment of a lowcost, real-time, portable, low power, and small form factor GNSS rebroadcaster. This device can be used both as a GNSS signal generator and as a GNSS signal regenerator. This device can be used to test the addition of new features in GNSS signals, such as new signals for ranging, and to characterize the performance of new and existing spoofing countermeasures for GNSS receivers in real time. This device does not require the use of post-processed GNSS signals, enabling the testing with live signals, for instance in a vehicular test campaign replicating the correct dynamic and channel impairments.
Gestalt: A Testbed For Experimentation And Validation Of Gnss Software Receivers
This paper presents a new platform for the experimentation with GNSS signals. It includes a set o... more This paper presents a new platform for the experimentation with GNSS signals. It includes a set of commercial of-the-shelf hardware and an open source software, constituting a state-of-the-art platform for research and development of next-generation GNSS receivers. The core of the platform is the GNSS-SDR receiver which has been extended to support multi-band and multi-system operations. As a relevant case of use to validate the research facility, we presented a triple band GNSS-SDR customization capable of receiving four GNSS signals in real-time: GPS L1 C/A, GPS L2CM, Galileo E1b, and Galileo E5a. In addition, we provided detailed descriptions of the receiver architecture, identifying the synchronization challenges of the multi-system satellite channels and providing practical and reproducible solutions. The source code developed to produce this paper has been released under the General Public License, and it is freely available on the Internet.
Fastening Gps And Galileo Tight With A Software Reciever
This paper presents the design, implementation and performance analysis of a hybrid GPS/Galileo s... more This paper presents the design, implementation and performance analysis of a hybrid GPS/Galileo software receiver. The proposed approach exploits the dissemination of Galileo-to-GPS time conversion parameters through Galileo's navigation message to mix pseudoranges of both constellations seamlessly, obtaining position fixes even with four satellites belonging to different systems. The approach is tested both with synthetically generated signals and with real-life signals using the four In-Orbit Validation Galileo satellites. The source code developed to produce this paper has been released under the General Public License, and it is freely available on the Internet.