Access profile

Ideal applicants are holders of master’s degrees in Information and Communication Technologies, and preferably Telecommunications Engineering. However, the multidisciplinary nature of some of the Department’s research groups makes it desirable to consider admitting candidates with other degrees in the fields of physics, computing, biology and computational linguistics.

In addition to this academic profile, certain characteristics are considered important for applicants to have, including interest in the research projects being carried out in the Department, having critical and analytical abilities, having initiative, being consistent and persistent in their work and being able to work in a team.

Degree classifications:

• Direct admission: European Master of Science in Research on Information and Communication Technologies (MERIT) and Master of Science in Communication and Network Engineering (COMNET). This last programme has not been submitted for verification, but it is expected to be verified very soon.
• Preferential admission: other postgraduate programmes in the field of ICT engineering: telecommunications engineering, telematic engineering, computer sciences and photonic technologies.
• Others: depending upon the presence of other multidisciplinary research groups in the Department, applicants with degrees from other programmes that do not coincide with the aforementioned profiles will also be considered: informatics, physical sciences, chemistry, mathematics, biology and computational linguistics.

An appropriate level of English is required for this programme.

Output profile

Doctoral candidates who complete a doctoral degree will have acquired the following competencies, which are needed to carry out quality research (Royal Decree 99/2011, of 28 January, which regulates official doctoral studies):

a) A systematic understanding of the field of study and a mastery of the research skills and methods related to the field.
b) An ability to conceive, design or create, put into practice and adopt a substantial process of research or creation.
c) An ability to contribute to pushing back the frontiers of knowledge through original research.
d) A capacity for critical analysis and an ability to assess and summarise new and complex ideas.
e) An ability to communicate with the academic and scientific community and with society in general as regards their fields of knowledge in the manner and languages that are typical of the international scientific community to which they belong.
f) An ability to foster scientific, technological, social, artistic and cultural progress in academic and professional contexts within a knowledge-based society.

The award of a doctoral degree must equip the graduate for work in a variety of settings, especially those requiring creativity and innovation. Doctoral graduates must have at least acquired the personal skills needed to:

a) Develop in contexts in which there is little specific information.
b) Find the key questions that must be answered to solve a complex problem.
c) Design, create, develop and undertake original, innovative projects in their field.
d) Work as part of a team and independently in an international or multidisciplinary context.
e) Integrate knowledge, deal with complexity and make judgements with limited information.
f) Offer criticism on and intellectually defend solutions.

Finally, with respect to competencies, doctoral students must:
a) have acquired advanced knowledge at the frontier of their discipline and demonstrated, in the context of internationally recognised scientific research, a deep, detailed and well-grounded understanding of theoretical and practical issues and scientific methodology in one or more research fields;
b) have made an original and significant contribution to scientific research in their field of expertise that has been recognised as such by the international scientific community;
c) have demonstrated that they are capable of designing a research project that serves as a framework for carrying out a critical analysis and assessment of imprecise situations, in which they are able to apply their contributions, expertise and working method to synthesise new and complex ideas that yield a deeper knowledge of the research context in which they work;
d) have developed sufficient autonomy to set up, manage and lead innovative research teams and projects and scientific collaborations (both national and international) within their subject area, in multidisciplinary contexts and, where appropriate, with a substantial element of knowledge transfer;
e) have demonstrated that they are able to carry out their research activity in a socially responsible manner and with scientific integrity;
f) have demonstrated, within their specific scientific context, that they are able to make cultural, social or technological advances and promote innovation in all areas within a knowledge-based society;
g) have demonstrated that they are able to participate in scientific discussions at the international level in their field of expertise and disseminate the results of their research activity to audiences of all kinds.

Number of places

30

Duration of studies and dedication regime

Duration
The maximum period of study for full-time doctoral studies is three years, counted from the date of admission to the programme to the date of submission of the doctoral thesis. The academic committee of the doctoral programme may authorise a doctoral candidate to pursue doctoral studies on a part-time basis. In this case, the maximum period of study is five years, counting from the date of admission to the programme to the date of submission of the doctoral thesis. For calculating these periods, the date of admission is considered to be the date of the first enrolment for tutorials, and the date of submission the moment in which the Doctoral School officially deposits the doctoral thesis.

For full-time doctoral candidates, the minimum period of study is two years, counted from the date of an applicant's admission to the programme until the date on which the doctoral thesis is deposited; for part-time doctoral candidates it is four years. When there are justified grounds for doing so, and the thesis supervisor and academic tutor have given their authorisation, doctoral candidates may request that the academic committee of their doctoral programme exempt them from the minimum period of study requirement.

The calculation of periods of study will not include periods of absence due to illness, pregnancy or any other reason provided for in the regulations in force. Students who find themselves in any of these circumstances must notify the academic committee of the doctoral programme, which, where appropriate, must inform the Doctoral School. Doctoral candidates may also temporarily withdraw from the programme for up to one year, and this period may be extended for an additional year. Doctoral candidates who wish to interrupt their studies must submit a justified request to the academic committee of the doctoral programme, which will decide whether or not to approve the request. Each programme will establish conditions for readmission to doctoral studies.

Extension
If full-time doctoral candidates have not applied to deposit their thesis by the end of the three-year period of study, the academic committee of the programme may authorise an extension of up to one year. In exceptional circumstances, a further one-year extension may be granted, subject to the conditions established by the corresponding doctoral programme. In the case of part-time doctoral candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

Dismissal from the doctoral programme
A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

Organization

• Muñoz Medina, Olga

• Ferrus Ferre, Ramon
• Mateu Mateu, Jordi
• Muñoz Medina, Olga
• Vall-Llossera Ferran, Mercè
• Villares Piera, Nemesio Javier

• Department of Signal Theory and Communications (PROMOTORA)

Doctoral Unit - ICT North Campus Management and Support Unit (UTGCNTIC)

C. Jordi Girona, 1-3. Building B4-003 (North Campus)
Tel.: 934 017 233
E-mail: doctorat.tsc@upc.edu

Access profile

Ideal applicants are holders of master’s degrees in Information and Communication Technologies, and preferably Telecommunications Engineering. However, the multidisciplinary nature of some of the Department’s research groups makes it desirable to consider admitting candidates with other degrees in the fields of physics, computing, biology and computational linguistics.

In addition to this academic profile, certain characteristics are considered important for applicants to have, including interest in the research projects being carried out in the Department, having critical and analytical abilities, having initiative, being consistent and persistent in their work and being able to work in a team.

Degree classifications:

• Direct admission: European Master of Science in Research on Information and Communication Technologies (MERIT) and Master of Science in Communication and Network Engineering (COMNET). This last programme has not been submitted for verification, but it is expected to be verified very soon.
• Preferential admission: other postgraduate programmes in the field of ICT engineering: telecommunications engineering, telematic engineering, computer sciences and photonic technologies.
• Others: depending upon the presence of other multidisciplinary research groups in the Department, applicants with degrees from other programmes that do not coincide with the aforementioned profiles will also be considered: informatics, physical sciences, chemistry, mathematics, biology and computational linguistics.

An appropriate level of English is required for this programme.

Access requirements

Applicants must hold a Spanish bachelor’s degree or equivalent and a Spanish master’s degree or equivalent, provided they have completed a minimum of 300 ECTS credits on the two degrees (Royal Decree 43/2015, of 2 February)

In addition, the following may apply:

• Holders of an official degree awarded by a university in Spain or any other country in the European Higher Education Area, pursuant to the provisions of Article 16 of Royal Decree 1393/2007, of 29 October, which establishes official university course regulations, who have completed a minimum of 300 ECTS credits on official university degrees, of which at least 60 must be at the master's degree level.
• Holders of an official Spanish bachelor’s degree comprising at least 300 credits, as provided for by EU regulations. Holder of degrees of this kind must complete bridging courses unless the curriculum of the bachelor’s degree in question included research training credits equivalent in value to those which would be earned on a master's degree.
• Holders of an official university qualification who, having passed the entrance examination for specialised medical training, have completed at least two years of a training course leading to an official degree in a health-sciences specialisation.
• Holders of a degree issued under a foreign education system. In these cases, homologation is not required, but the UPC must verify that the degree certifies a level of training equivalent to an official Spanish master's degree and qualifies the holder for admission to doctoral studies in the country where it was issued. Admission on this basis does not imply homologation of the foreign degree or its recognition for any purpose other than admission to doctoral studies.
• Holders of a Spanish doctoral qualification issued under previous university regulations.

Note 1: Doctoral studies entrance regulations for holders of an undergraduate degree awarded before the introduction of the EHEA (CG 47/02 2014)

Note 2: Governing Council Decision 64/2014, which approves the procedure and criteria for assessing the fulfilment of academic admission requirements for doctoral studies by holders of non-homologated foreign degrees (CG 25/03 2014)

Admission criteria and merits assessment

• Appropriateness of academic background with the activities carried out in the proposed research group: 25%.
• Knowledge of the English language: 20%.
• Quality of university from which previous degree was awarded: 10%.
• Motivation letter/letters of recommendation: 10%.

An assessment will be considered positive is an applicant is given a score of 3 or more out of 5.

Based on the content of the motivation letter and the applicant’s preparedness, the Postgraduate Committee will assign a thesis supervisor.

If candidates do not have a degree in some kind of ICT engineering, they will have to take the bridging courses recommended by their supervisors and the programme, whether courses from the associated master’s programmes (MET, MATT) or other ones.

Training complements

The Postgraduate Committee of the Signal Theory and Communications Department may require candidates to complete specific bridging courses. In this case, the Committee will monitor the bridging courses and set up appropriate criteria to limit their length.

The courses shall involve training in research, but in no case will candidates be required to enrol in 60 or more ECTS credits (according to the academic regulations for doctoral studies, bridging courses could include transversal education, but there are plans to change to this so that these bridging courses exclusively provide research credits, especially in cases involving doctoral programmes with 300 ECTS credits).

Depending on the activities completed by the candidates, the Postgraduate Committee of the Signal Theory and Communications Department may propose measures, in addition to those established by current regulations, that would disassociate candidates who do not meet the established requisites.

The Postgraduate Committee may require candidates who are to be admitted to complete certain bridging courses in order to better adapt their profiles to the programme’s requirements regarding the knowledge necessary to properly complete the doctoral studies.

No bridging courses will be required for those who graduated from the MET, MASTEAM or MATT programmes, or any of the other previously mentioned ICT programmes.

For those who completed other programmes, the bridging coursework required will depend upon their backgrounds and the activities carried out by the research groups in which they will participate, and it could be up to 30 ECTS.

The courses to be taken are offered by the MET, MASTEAM or MATT programmes.

Also, depending on the characteristics of some of the Department’s research groups, courses from the following UPC programmes will also be considered:
• Master’s programme in Telecommunications Engineering
• Master’s programme in Electrical Engineering
• Master’s programme in Photonics
• Master’s programme in Innovation and Research in Informatics
• Master’s programme in Artificial Intelligence

After consulting with candidates’ supervisors, it will be the sole responsibility of the TSC Department’s Postgraduate Committee to determine which courses students will have to take to complete these bridging courses. In any case, the aim of the courses will always be to fill in the gaps that students are seen to have in their academic transcripts with regard to the activities carried out by the research group in which they will participate.

Enrolment period for new doctoral students

Students enrolling in the doctoral programme for the first time must do so by the deadline specified in the admission decision.
Unless otherwise expressly indicated, enrolments corresponding to admission decisions issued from the second half of April on must be completed within the ordinary enrolment period for the current academic year.

More information at the registration section for new doctoral students

Enrolment period

Ordinary period for second and successive enrolments: first half of October.

More information at the general registration section

Procedure for the preparation and defense of the research plan

Doctoral candidates must submit a research plan, which will be included in their doctoral student activity report, before the end of the first year. The plan may be improved over the course of the doctoral degree. It must be endorsed by the tutor and the supervisor, and it must include the method that is to be followed and the aims of the research.

At least one of these annual assessments will include a public presentation and defence of the research plan and work done before a committee composed of three doctoral degree holders, which will be conducted in the manner determined by each academic committee. The examination committee awards a Pass or Fail mark. A Pass mark is a prerequisite for continuing on the doctoral programme. Doctoral candidates awarded a Fail mark must submit a new research plan for assessment by the academic committee of the doctoral programme within six months.

The committee assesses the research plan every year, in addition to all of the other activities in the doctoral student activity report. Doctoral candidates who are awarded two consecutive Fail marks for the research plan will be obliged to definitely withdraw from the programme.

If they change the subject of their thesis, they must submit a new research plan.

Formation activities

Activity: Tutorial.
- Hours: 288.
- Type: compulsory.

Activity: Mobility.
- Hours: 480.
- Type: optional.

Activity: Assessment based on doctoral student activity report (DAD) and research plan.
- Hours: 4.
- Type: compulsory.

Activity: Training in information skills.
- Hours: 1,5.
- Type: compulsory.

Activity: Research methodology.
- Hours: 12.
- Type: compulsory.

Activity: Innovation and creativity.
- Hours: 8.
- Type: optional.

Activity: Language and communication skills.
- Hours: 18.
- Type: optional.

Activity: Courses and seminars.
- Hours: 50.
- Type: optional.

Activity: Workshops.
- Hours: 8.
- Type: optional.

Procedure for assignment of tutor and thesis director

The academic committee of the doctoral programme assigns a thesis supervisor to each doctoral candidate when they are admitted or enrol for the first time, taking account of the thesis supervision commitment referred to in the admission decision.

The thesis supervisor will ensure that training activities carried out by the doctoral candidate are coherent and suitable, and that the topic of the candidate’s doctoral thesis will have an impact and make a novel contribution to knowledge in the relevant field. The thesis supervisor will also guide the doctoral candidate in planning the thesis and, if necessary, tailoring it to any other projects or activities undertaken. The thesis supervisor will generally be a UPC professor or researcher who holds a doctoral degree and has documented research experience. This includes PhD-holding staff at associated schools (as determined by the Governing Council) and UPC-affiliated research institutes (in accordance with corresponding collaboration and affiliation agreements). When thesis supervisors are UPC staff members, they also act as the doctoral candidate’s tutor.

PhD holders who do not meet these criteria (as a result of their contractual relationship or the nature of the institution to which they are attached) must be approved by the UPC Doctoral School's Standing Committee in order to participate in a doctoral programme as researchers with documented research experience.

The academic committee of the doctoral programme may approve the appointment of a PhD-holding expert who is not a UPC staff member as a candidate’s thesis supervisor. In such cases, the prior authorisation of the UPC Doctoral School's Standing Committee is required. A UPC staff member who holds a doctoral degree and has documented research experience must also be proposed to act as a co-supervisor, or as the doctoral candidate’s tutor if one has not been assigned.

A thesis supervisor may step down from this role if there are justified reasons (recognised as valid by the committee) for doing so. If this occurs, the academic committee of the doctoral programme will assign the doctoral candidate a new thesis supervisor.

Provided there are justified reasons for doing so, and after hearing any relevant input from the doctoral candidate, the academic committee of the doctoral programme may assign a new thesis supervisor at any time during the period of doctoral study.

If there are academic reasons for doing so (an interdisciplinary topic, joint or international programmes, etc.) and the academic committee of the programme gives its approval, an additional thesis supervisor may be assigned. Supervisors and co-supervisors have the same responsibilities and academic recognition.

The maximum number of supervisors of a doctoral thesis is two: a supervisor and a co-supervisor.

For theses carried out under a cotutelle agreement or as part of an Industrial Doctorate, if necessary and if the agreement foresees it this maximum number of supervisors may not apply. This notwithstanding, the maximum number of supervisors belonging to the UPC is two.

More information at the PhD theses section

Permanence

The academic committee of the programme may authorise an extension of up to one year for full-time doctoral candidates who have not applied to deposit their thesis by the end of the three-year period of study, in the terms outlined in the Academic Regulations for Doctoral Studies of the Universitat Politècnica de Catalunya. In the case of part-time candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

International Mention

The doctoral degree certificate may include International Doctorate mention. In this case, the doctoral candidate must meet the following requirements:

a) During the period of study leading to the award of the doctoral degree, the doctoral candidate must have spent at least three months at a respected higher education institution or research centre outside Spain to complete courses or do research work. The stays and activities carried out must be endorsed by the thesis supervisor and authorised by the academic committee of the programme. The candidate must provide a certifying document issued by the person responsible for the research group of the body or bodies where the stay or activity was completed. This information will be added to the doctoral student’s activity report.
b) Part of the thesis (at least the summary and conclusions) must be written and presented in one of the languages commonly used for science communication in the relevant field of knowledge, which must not be an official language of Spain. This rule does not apply to stays and reports in Spanish or to experts from Spanish-speaking countries.
c) At least two PhD-holding experts belonging to a higher education institution or research centre outside Spain must have issued officially certified reports on the thesis.
d) The thesis examination committee must have included at least one PhD-holding expert from a higher education or research institution outside Spain who was not responsible for the candidate’s stay abroad (point a) above).
e) The thesis defence must have taken place on UPC premises or, in the case of joint programmes, at the location specified in the collaboration agreement.

List of authorized thesis for defense

• BASTA, CHRISTINE RAOUF SAAD: Gender bias in natural language processing
  
  Author: BASTA, CHRISTINE RAOUF SAAD
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 25/07/2022
  Reading date: 14/10/2022
  Reading time: 16:00
  Reading place: ETSETB B3 Teleensenyament, campus nord
  Thesis director: RUIZ COSTA-JUSSA, MARTA
  Committee:
       PRESIDENT: CHANG, KAI-WEI
       SECRETARI: NADEU CAMPRUBI, CLIMENT
       VOCAL: DIAB, MONA TALAT
  Thesis abstract: Gender bias is a dangerous form of social bias impacting an essential group of people. The effect of gender bias is propagated to our data, causing the accuracy of the predictions in models to be different depending on gender. In the deep learning era, our models are highly impacted by the training data transferring the negative biases in the data to the models. Natural Language Processing models encounter this amplification of bias in the data. Our thesis is devoted to studying the issue of gender bias in NLP applications from different points of view. To understand and manage the effect of bias amplification, evaluation and mitigation approaches have to be explored. The scientific society has exerted significant efforts in these two directions to enable proposing solutions to the problem. Our thesis is devoted to these two main directions; proposing evaluation schemes, whether as datasets or mechanisms, besides suggesting mitigation techniques. For evaluation, we proposed techniques for evaluating bias in contextualized embeddings and multilingual translation models. Besides, we presented benchmarks for evaluating bias for speech translation and multilingual machine translation models. For mitigation direction, we proposed different approaches in machine translation models by adding contextual text, contextual embeddings, or relaxing the architecture¿s constraints. Our evaluation studies concluded that gender bias is encoded strongly in contextual embeddings representing professions and stereotypical nouns. We also unveiled that algorithms amplify the bias and that the system¿s architecture impacts the behavior. For the evaluation purposes, we contributed to creating several benchmarks for the evaluation purpose; we introduced a benchmark that evaluates gender bias in speech translation systems. This research suggests that the current state of speech translation systems does not enable us to evaluate gender bias accurately because of the low quality of speech translation systems. Additionally, we proposed a toolkit for building multilingual balanced datasets for training and evaluating NMT models. These datasets are balanced within the gender occupation-wise. We found out that high-resource languages usually tend to predict more precise male translations. Our mitigation studies in NMT suggest that the nature of datasets and languages needs to be considered to apply the right approach. Mitigating bias can rely on adding contextual information. However, in other cases, we need to rethink the model and relax some influencing conditions to the bias that do not affect the general performance but reduce the effect of bias amplification.
  

Last update: 06/10/2022 04:45:23.

List of lodged theses

• INDIA MASSANA, MIQUEL ANGEL: Deep learning methods for speaker verification and diarization
  
  Author: INDIA MASSANA, MIQUEL ANGEL
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 30/09/2022
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: HERNANDO PERICAS, FRANCISCO JAVIER
  Committee:
       PRESIDENT: ORTEGA GIMENEZ, ALFONSO
       SECRETARI: NADEU CAMPRUBI, CLIMENT
       VOCAL: LOZANO DIEZ, ALICIA
  Thesis abstract: This thesis verses about how Deep Learning (DL) methods and algorithms can be applied to solve many of the challenges in the speaker recognition field. The work of this thesis is specifically focused on the implementation of attention models as pooling methods for speaker verification and on the addition of linguistic content as a feature for speaker diarization.Speaker recognition field comprises a set of different tasks based on identifying, verifying and locating speaker identities from the audio signal. These tasks can be solved by algorithms which need a high capacity of discrimination between speakers. For the last years, DL methods have become state of the art (SOTA) in discriminative features and patterns extraction from unstructured data such as images, text and speech. This has motivated the research on the use and adaptation of some DL architectures for speaker recognition tasks. Although DL topologies can not individually solve all these speaker recognition tasks, they can solve many of them globally and be partially used for the rest of the tasks. Furthermore, DL topologies are not only attractive for their discriminative power but also for their input flexibility that allows inputs from different domains and shapes to be combined. This has further motivated the exploration of some research paths in speaker recognition that were more difficult to pursue prior to recent DL advances. The first part of this thesis is based on the use of attention models for speaker verification. SOTA systems for this task are based on speaker embedding extractors. These architectures are comprised by combinations of DL topologies which are trained as speaker classifiers but used to extract low-dimensional and discriminative speaker representations. These speaker embedding extractors are commonly composed by a Deep Neural Network (DNN) based feature extractor, a pooling stage and a final Fully Connected (FC) block. In this thesis we will focus on the pooling block, which aims to map sequences of temporal features onto non temporal low-dimensional vectors. This mapping was initially proposed as a straight-forward statistical method, which extracted the mean or both then mean and the standard deviation. On the other hand, attention models have been one of the most used topologies in fields like Natural Language Processing (NLP) or Computer Vision (CV). Given an input, these topologies allow selecting the most discriminative sections of that input according to the task to be solved. For the pooling stage this implies using attention models to select which are the most relevant regions in the signal to extract speaker traits for the embedding creation. In this part of the thesis we will explore different attention methods or the pooling stage. Multi-Head Attention (MHA) will be explored firstly, which will allow to efficiently extract different sets of features from different regions of the data. Our experiments will demonstrate how this method outperforms both temporal and vanilla attention poolings. Secondly, we will present Double MHA pooling model, which is a MHA extension less sensible to some hyper-parameters than the previous one. The results shown will indicate that Double MHA is a more discriminative and less sensitive pooling method than MHA and vanilla attention.The second part of this thesis aims to combine different domain inputs for speaker diarization. In some scenarios it is known that some linguistic patterns that can be extracted from audio could be used to distinguish the identities of the speakers. In fact, some scenarios, such as dialogues between operator and customer in Call-Centers have clear speaker linguistic patterns. SOTA methods for [...]
  
• KRKOTIC, PATRICK: Evaluation of the Surface Impedance of ReBCO Coated Conductors and Requirements for Their Use as Beam Screen Materials for the FCC-hh
  
  Author: KRKOTIC, PATRICK
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 29/09/2022
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: O'CALLAGHAN CASTELLA, JUAN MANUEL | PONT, MONTSERRAT
  Committee:
       PRESIDENT: IRISO ARIZ, UBALDO
       SECRETARI: DUFFO UBEDA, NURIA
       VOCAL: WUENSCH, WALTER
  Thesis abstract: The Future Circular Hadron Collider (FCC-hh) is a proposal for a 100-kilometre-long particle accelerator with collision energy substantially higher than previous colliders to expand the Large Hadron Collider (LHC) research. The selection of a low surface impedance beam screen coating material for such a high-energy collider has become of fundamental importance to ensure sufficiently low beam impedance and guarantee stable accelerator operation at high beam currents. Currently, copper is the baseline coating material. In comparison to it, only high-temperature superconductors (HTSs) in the form of ReBCO coated conductors (ReBCO-CCs) have a lower surface impedance and would provide for higher margins of beam stability at the expected operating temperature (40 - 60 K). Whilst theoretical studies of HTSs under FCC-hh conditions have proved encouraging, no experimental data of ReBCO-CCs subject to FCC-hh conditions exists to confirm these predictions. This thesis provides two main contributions: First, it presents the experimental set-ups designed and constructed to measure the surface impedance of ReBCO-CCs, on the basis of dielectric resonator structures of Hakki-Coleman and parallel plate type under AC and DC magnetic fields, photon irradiation, all at cryogenic temperatures, to mimic the environment of the beam screen in the FCC-hh. We also developed DROMS, an automated data acquisition software, and ARPE, a post-processing algorithm toaccurately extract the parameters of the dielectric resonators -resonance frequency and quality factor- from the S-parameters of the vector network analyser. The second contribution consists in the results from experimentally-measured surface impedance of ReBCO-CCs from six different manufacturers. We present surface impedance as a function of temperature and under strong magnetic fields in the gigahertz range. Complementary to this, we analysed the non-linear behaviour of ReBCO-CCs in the presence of a magnetic field superimposed on radio-frequency electromagnetic fields with amplitudes comparable to the ones generated by proton bunches in the FCC-hh. Finally, we studied the effect of photon irradiation on the surface resistance in-situ and ex-situ, at the ALBA Synchrotron Light Source. Extrapolating from our data to 16 T and 1 GHz demonstrates the possibility oflowering the surface resistance of the beam screen by up to two orders of magnitude by using ReBCO-CCs instead of copper while the surface reactance is at the same order of magnitude. We conclude that ReBCO-CCs are suitable candidates to significantly reduce the resistive wall impedance in the FCC-hh.
  
• SALGUEIRO ROMERO, LUIS FERNANDO: Super-resolution and semantic segmentation of remote sensing images using deep learning techniques
  
  Author: SALGUEIRO ROMERO, LUIS FERNANDO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Temporary seizure
  Deposit date: 28/09/2022
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: VILAPLANA BESLER, VERONICA | MARCELLO RUIZ, JAVIER
  Committee:
       PRESIDENT: GONZALO MARTÍN, MARIA DEL CONSUELO
       SECRETARI: MARQUES ACOSTA, FERNANDO
       VOCAL: EUGENIO GONZÁLEZ, FRANCISCO
  Thesis abstract: Remote sensing for Earth observation is a growing scientific field essential for many human activities. Among the different applications in the Remote Sensing domain, the production of thematic maps, such as Land Cover and Land Use, are among the most relevant, as this information plays a critical role in management, planning and monitoring activities at different levels. In this context, the Sentinel-2 satellites are of great importance since they provide open data on land and coastal areas at different spatial resolutions (10, 20, and 60 m), democratizing usability, and creating a high potential for the generation of valuable information, useful in many scenarios, such as agriculture, forestry, land cover and urban planning, among others.In this thesis, we aim to exploit the usability of Sentinel-2 data by applying deep learning techniques, which are revolutionizing the world of computer vision and, recently, remote sensing. First, we propose super-resolution models to improve the spatial details of the different Sentinel-2 bands, and second, we propose the conjunction of semantic segmentation with super-resolution to generate improved land cover maps that benefit from the enhanced spatial details of the bands.We first address super-resolution by proposing two different models, one for the 10 m/pixel bands to reach 2 m/pixel and another for the 20 and 60 m/pixel bands to achieve 10 m/pixel. Then, we propose two different multitasking models to derive land cover maps. The first one extending a semantic segmentation model to produce an additional super-resolution image and the second, improving our first super-resolution approach, to provide a semantic segmentation map, as well. We combine features of the different tasks within a single model to improve performance and to generate a high-resolution image with the corresponding high- quality land cover map. All models developed were evaluated, quantitatively and qualitatively, using different datasets, showing excellent performance in diverse complex scenarios.
  
• SARRIGIANNIS, IOANNIS: SFC Placement and lifecycle management in edge-enabled 5G architectures
  
  Author: SARRIGIANNIS, IOANNIS
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Deposit date: 28/09/2022
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: ANTONOPOULOS, ANGELOS | RAMANTAS, KONSTANTINOS
  Committee:
       PRESIDENT: PEREZ ROMERO, JORGE
       SECRETARI: SIOKIS, APOSTOLOS
       VOCAL: FIORE, MARCO
  Thesis abstract: The fifth generation (5G) of mobile communications urges software defined networking (SDN) and network function virtualization (NFV) to join forces with the multi-access edge computing (MEC) cause. Thus, reduced latency and increased capacity at the edge of the network can be achieved, to satisfy the requirements of a diverse ecosystem where multiple virtualization technologies (VTs) may be employed. 5G service providers highly rely on network softwarization for addressing the latency and resource demanding use cases of the 5G vertical industries, where both applications and network functions are incorporated into virtual network functions (VNFs). If not properly orchestrated, the flexibility of deployment, placement and lifecycle management (LCM) that the VNFs manifest, may cause serious issues in the NFV scheme. As the service level agreements (SLAs) of the 5G applications compete in an environment with traffic variations and VNF placement options with diverse compute and network resources, online placement techniques and advanced LCM approaches become mandatory.The local breakout that MEC-enabled architectures offer, signify that the data will not have to cross the entire network until they reach the application and return to the user, as the application is running at the MEC that is, usually, collocated with the access network.In this thesis, we tackle the challenges that arise in core and edge-enabled 5G architectures, and we elaborate how the different schemes of VNF deployments as VTs can be used and collaborate to support the automotive and Internet of things (IoT) use cases, as well as more demanding use cases that derive from the combination of various vertical industries. We go beyond the current state-of-the-art solutions by proposing innovative resource allocation and LCM-enabled scheduling algorithms. Furthermore, we focus on the challenges that arise in single-domain or federated environments, where the flexible placement and LCM of VNFs is supported by the NFV orchestrator (NFVO) that is able to manage, on-the-fly, the network functions and resources. Additionally, we deal with the limitations of the intelligence of the NFVO by providing service aware latency-based embedding and placement mechanisms. Moreover, we propose online scheduling and LCM algorithms where the VNFs are instantiated, scaled, migrated and destroyed based on the actual traffic, respecting the SLA of the 5G use cases, as well as the overall deployment and execution cost.Our work is supported by our versatile, open-source and custom-built 5G experimental platform, modified and adapted at each architecture to support the corresponding 5G use cases. The experimental results demonstrate the efficiency of our innovative algorithms and their efficacy to deal with the VNF placement and resource reallocation and optimization problems in actual demanding environments with unpredictable traffic schemes.Our methods allow the maximization of the total number of users served and the adaptation to real-time incoming traffic. At the same time, the application SLAs are respected in a cost-efficient way.
  

Last update: 06/10/2022 04:30:28.

List of defended theses by year

• BALLESTEROS SÁNCHEZ, CHRISTIAN: Mobile 5G Millimeter-wave multi-antenna systems
  
  Author: BALLESTEROS SÁNCHEZ, CHRISTIAN
  Thesis link: http://hdl.handle.net/10803/674995
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Article-based thesis
  Reading date: 21/07/2022
  Thesis director: JOFRE ROCA, LUIS
  

  Committee:
       PRESIDENT: VALERO NOGUEIRA, ALEJANDRO
       SECRETARI: RIUS CASALS, JUAN-MANUEL
       VOCAL: HEINO, MIKKO
  Thesis abstract: Massive antenna architectures and millimeter-wave bands appear on the horizon as the enabling technologies of future broadband wireless links, promising unprecedented spectral efficiency and data rates. In the recently launched fifth generation of mobile communications, millimetric bands are already introduced but their widespread deployment still presents several feasibility issues.In particular, high-mobility environments represent the most challenging scenario when dealing with directive patterns, which are essential for the adequate reception of signals at those bands. Vehicular communications are expected to exploit the full potential of future generations due to the massive number of connected users and stringent requirements in terms of reliability, latency, and throughput while moving at high speeds. This thesis proposes two solutions to completely take advantage of multi-antenna systems in those cases: beamwidth adaptation of cellular stations when tracking vehicular users based on positioning and Doppler information and a tailored radiation diagram from a panel-based system of antennas mounted on the vehicle.Apart from cellular base stations and vehicles, a third entity that cannot be forgotten in future mobile communications are pedestrians. Past generations were developed around the figure of human users and, now, they must still be able to seamlessly connect with any other user of the network and exploit the new capabilities promised by 5G. The use of millimeter-waves is already been considered by handset manufacturers but the impact of the user (and the interaction with the phone) is drastically changed. The last part of this thesis is devoted to the study of human user dynamics and how they influence the achievable coverage with different distributed antenna systems on the phone.
  

• CARDOSO DUARTE, AMANDA: Data and methods for a visual understanding of sign languages
  
  Author: CARDOSO DUARTE, AMANDA
  Thesis link: http://hdl.handle.net/10803/674738
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 27/06/2022
  Thesis director: GIRÓ NIETO, XAVIER | TORRES VIÑALS, JORDI
  

  Committee:
       PRESIDENT: SMEATON, ALAN
       SECRETARI: SAYROL CLOLS, ELISA
       VOCAL NO PRESENCIAL: ROGEZ, GRÉGORY
  Thesis abstract: Signed languages are complete and natural languages used as the first or preferred mode of communication by millions of people worldwide. However, they, unfortunately, continue to be marginalized languages. Designing, building, and evaluating models that work on sign languages presents compelling research challenges and requires interdisciplinary and collaborative efforts. The recent advances in Machine Learning (ML) and Artificial Intelligence (AI) has the power to enable better accessibility to sign language users and narrow down the existing communication barrier between the Deaf community and non-sign language users. However, recent AI-powered technologies still do not account for sign language in their pipelines. This is mainly because sign languages are visual languages, that use manual and non-manual features to convey information, and do not have a standard written form. Thus, the goal of this thesis is to contribute to the development of new technologies that account for sign language by creating large-scale multimodal resources suitable for training modern data-hungry machine learning models and developing automatic systems that focus on computer vision tasks related to sign language that aims at learning better visual understanding of sign languages.Thus, in Part I, we introduce the How2Sign dataset, which is a large-scale collection of multimodal and multiview sign language videos in American Sign Language. In Part II, we contribute to the development of technologies that account for sign languages by presenting in Chapter 4 a framework called Spot-Align, based on sign spotting methods, to automatically annotate sign instances in continuous sign language. We further present the benefits of this framework and establish a baseline for the sign language recognition task on the How2Sign dataset. In addition to that, in Chapter 5 we benefit from the different annotations and modalities of the How2Sign to explore sign language video retrieval by learning cross-modal embeddings. Later in Chapter 6, we explore sign language video generation by applying Generative Adversarial Networks to the sign language domain and assess if and how well sign language users can understand automatically generated sign language videos by proposing an evaluation protocol based on How2Sign topics and English translation.
  

• DU, SEN: Three dimensional temporal-spatial model based SAR algorithms for monitoring large gradient deformations in mining area
  
  Author: DU, SEN
  Thesis link: http://hdl.handle.net/10803/674343
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 13/05/2022
  Thesis director: MALLORQUI FRANQUET, JORDI JOAN
  

  Committee:
       PRESIDENT: FERNÁNDEZ TORRES, JOSÉ
       SECRETARI: BROQUETAS IBARS, ANTONI
       VOCAL: LÓPEZ SÁNCHEZ, JUAN MANUEL
  Thesis abstract: Firstly, an External Model Deformation Decomposition based Persistent Scatters Interferometry (EMDD-PSI) method has been proposed. This method ?rst uses original interferograms to optimize the parameters of the external model. Then, the number of fringes in the original interferograms are reduced by the external model to ease the PSI processing. Finally, the ground deformation is retrieved jointly adding the external model and PSI results. The capability of the proposed method is demonstrated with 14 Radarsat-2 SAR images over the Fengfeng mining area (China). The proposed method is evaluated with the leveling data. Results have shown that after the optimization, the external model is able to mimic the real deformation.Second, to reduce the PL, a novel amplitude ?lter, i.e. the Pacth-Like Re- duction (PLR), is developed. The proposed PLR educes the PL e?ects by replacing the pixels with extremely high amplitudes with zero. Three di?erent SAR data sets and in- ?eld Global Positioning System (GPS) measurements are used to evaluate the performance of the proposed method. The results show that PL e?ects can be reduced with the proposed amplitude ?lter. Third, a polarization data based Amplitude Contrast Enhancement O?set Tracking (ACE-OT) is proposed. The method can enhance the contrast of SAR amplitude image by searching for the optimal combination of three different scattering mechanism. The 31 quad-pol Radarsat-2 images covering Barcelona Airport and 20 dual-pol TerraSAR-X images are used to verify the proposed method. The enhancement result shows that the contrasts of the amplitude images are increased, which also improves the correlation of the image pair. Therefore, the ACE-OT can achieve better results than the OT with unenhanced amplitude images.
  

• ESCOLANO PEINADO, CARLOS: Learning multilingual and multimodal representations with language-specific encoders and decoders for Machine translation
  
  Author: ESCOLANO PEINADO, CARLOS
  Thesis link: http://hdl.handle.net/10803/673982
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 18/03/2022
  Thesis director: RUIZ COSTA-JUSSA, MARTA | RODRIGUEZ FONOLLOSA, JOSE ADRIAN
  

  Committee:
       PRESIDENT: LABAKA INTXAUSPE, GORKA
       SECRETARI: MARQUEZ VILLODRE, LUIS
       VOCAL: VINYALS ARGELAGUET, ORIOL
  Thesis abstract: This thesis aims to study different language-specific approaches for Multilingual Machine Translation without parameter sharing and their properties compared to the current state-of-the-art based on parameter-sharing. We define Multilingual Machine Translation as the task that focuses on methods to translate between several pairs of languages in a single system. It has been widely studied in recent years due to its ability to easily scale to more languages, even between pairs never seen together during training (zero-shot translation). Several architectures have been proposed to tackle this problem with varying amounts of shared parameters between languages. Current state-of-the-art systems focus on a single sequence-to-sequence architecture where all languages share the complete set of parameters, including the token representation. While this has proven convenient for transfer learning, it makes it challenging to incorporate new languages into the trained model as all languages depend on the same parameters. What all proposed architectures have in common is enforcing a shared presentation space between languages. Specifically, during this work, we will employ as representation the final output of the encoders that the decoders will use to perform cross-attention. Having a shared space reduces noise as similar sentences at semantic level produce similar vectorial representations, helping the decoders process representations from several languages. This semantic representation is particularly important for zero-shot translation as the representation similarity to the languages pairs seen during training is key to reducing ambiguity between languages and obtaining good translation performance. This thesis is structured in three main blocks, focused on different scenarios of this task. Firstly, we propose a training method that enforces a common representation for bilingual training and a procedure to extend it to new languages efficiently. Secondly, we propose another training method that allows this representation to be learned directly on multilingual data and can be equally extended to new languages. Thirdly, we show that the proposed multilingual architecture is not limited only to textual languages. We extend our method to new data modalities by adding speech encoders, performing Spoken Language Translation, including Zero-Shot, to all the supported languages. Our main results show that the common intermediate representation is achievable in this scenario, matching the performance of previously shared systems while allowing the addition of new languages or data modalities efficiently without negative transfer learning to the previous languages or retraining the system.
  

• HERBERT, CHRISTOPH JOSEF: Advanced methods for earth observation data synergy for geophysical parameter retrieval
  
  Author: HERBERT, CHRISTOPH JOSEF
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 15/07/2022
  Thesis director: VALL-LLOSSERA FERRAN, MERCEDES MAGDALENA | CAMPS CARMONA, ADRIANO JOSE
  

  Committee:
       PRESIDENT: WICKERT, JENS
       SECRETARI: CORBELLA SANAHUJA, IGNASI
       VOCAL: LÓPEZ SÁNCHEZ, JUAN MANUEL
  Thesis abstract: The first part of the thesis focuses on the analysis of relevant factors to estimate the response time between satellite-based and in-situ soil moisture (SM) using a Dynamic Time Warping (DTW). DTW was applied to the SMOS L4 SM, and was compared to in-situ root-zone SM in the REMEDHUS network in Western Spain. The method was customized to control the evolution of time lag during wetting and drying conditions. Climate factors in combination with crop growing seasons were studied to reveal SM-related processes. The heterogeneity of land use was analyzed using high-resolution images of NDVI from Sentinel-2 to provide information about the level of spatial representativity of SMOS data to each in-situ station. The comparison of long-term precipitation records and potential evapotranspiration allowed estimation of SM seasons describing different SM conditions depending on climate and soil properties. The second part of the thesis focuses on data-driven methods for sea ice segmentation and parameter retrieval. A Bayesian framework is employed to segment sets of multi-source satellite data. The Bayesian unsupervised learning algorithm allows to investigate the `hidden link¿ between multiple data. The statistical properties are accounted for by a Gaussian Mixture Model, and the spatial interactions are reflected using Hidden Markov Random Fields. The algorithm segments spatial data into a number of classes, which are represented as a latent field in physical space and as clusters in feature space. In a first application, a two-step probabilistic approach based on Expectation-Maximization and the Bayesian segmentation algorithm was used to segment SAR images to discriminate surface water from sea ice types. Information on surface roughness is contained in the radar backscattering images which can be - in principle - used to detect melt ponds and to estimate high-resolution sea ice concentration (SIC). In a second study, the algorithm was applied to multi-incidence angle TB data from the SMOS L1C product to harness the its sensitivity to thin ice. The spatial patterns clearly discriminate well-determined areas of open water, old sea ice and a transition zone, which is sensitive to thin sea ice thickness (SIT) and SIC. In a third application, SMOS and the AMSR2 data are used to examine the joint effect of CIMR-like observations. The information contained in the low-frequency channels allows to reveal ranges of thin sea ice, and thicker ice can be determined from the relationship between the high-frequency channels and changing conditions as the sea ice ages. The proposed approach is suitable for merging large data sets and provides metrics for class analysis, and to make informed choices about integrating data from future missions into sea ice products. A regression neural network approach was investigated with the goal to infer SIT using TB data from the Flexible Microwave Payload 2 (FMPL-2) of the FSSCat mission. Two models - covering thin ice up to 0.6m and the full-range of SIT - were trained on Arctic data using ground truth data derived from the SMOS and Cryosat-2. This work demonstrates that moderate-cost CubeSat missions can provide valuable data for applications in Earth observation.
  

• LIESEGANG MARIA, SERGI: Energy-driven techniques for massive machine-type communications
  
  Author: LIESEGANG MARIA, SERGI
  Thesis link: http://hdl.handle.net/10803/675389
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 07/09/2022
  Thesis director: MUÑOZ MEDINA, OLGA | PASCUAL ISERTE, ANTONIO
  

  Committee:
       PRESIDENT: VAZQUEZ GRAU, GREGORIO
       SECRETARI: LAGÉN MORANCHO, SANDRA
       VOCAL: GARCÍA MARQUÉS, ANTONIO
  Thesis abstract: In the last few years, a lot of effort has been put into the development of the fifth generation of cellular networks (5G). Given the vast heterogeneity of devices coexisting in these networks, new approaches have been sought to meet all requirements (e.g., data rate, coverage, delay, etc.). Within that framework, massive machine-type communications (mMTC) emerge as a promising candidate to enable many Internet of Things applications. mMTC define a type of systems where large sets of simple and battery-constrained devices transmit short data packets simultaneously. Unlike other 5G use cases, in mMTC, a low cost and power consumption are extensively pursued. Due to these specifications, typical humantype communications (HTC) solutions fail in providing a good service. In this dissertation, we focus on the design of energy-driven techniques for extending the lifetime of mMTC terminals. Both uplink (UL) and downlink (DL) stages are addressed, with special attention to the traffic models and spatial distribution of the devices. More specifically, we analyze a setup where groups of randomly deployed sensors send their (possibly correlated) observations to a collector node using different multiple access schemes. Depending on their activity, information might be transmitted either on a regular or sporadic basis. In that sense, we explore resource allocation, data compression, and device selection strategies to reduce the energy consumption in the UL. To further improve the system performance, we also study medium access control protocols and interference management techniques that take into account the large connectivity in these networks. On the contrary, in the DL, we concentrate on the support of wireless powered networks through different types of energy supply mechanisms, for which proper transmission schemes are derived. Additionally, for a better representation of current 5G deployments, the presence of HTC terminals is also included. Finally, to evaluate our proposals, we present several numerical simulations following standard guidelines. In line with that, we also compare our approaches with state-of-the-art solutions. Overall, results show that the power consumption in the UL can be reduced with still good performance and that the battery lifetimes can be improved thanks to the DL strategies.
  

• NUÑO GÓMEZ, DANIEL-JUAN: Photonic circuits for wireless applications in the microwave, millimeter wave and terahertz bands
  
  Author: NUÑO GÓMEZ, DANIEL-JUAN
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Temporary seizure
  Reading date: 23/09/2022
  Thesis director: SANTOS BLANCO, MARÍA CONCEPCIÓN
  

  Committee:
       PRESIDENT: SEGOVIA VARGAS, DANIEL
       SECRETARI: DIOS OTIN, VICTOR FEDERICO
       VOCAL: FÀBREGA SÁNCHEZ, JOSEP MARIA
  Thesis abstract: This thesis focuses on the emission, processing and detection of electromagnetic radiation in applications where theuse of established technologies may limit the achievable frequency or bandwidth. Leveraging hybrid photonic-electronic approaches, different technologies allowing unique access to extremely high frequencies and bandwidths are studied in this thesis. Considering the world wide use of optical communications, Microwave Photonics (MWP) filtering stands as a technology that can potentially transform the signal distribution leveraging the existing optical fiber infrastructure. An in depthanalysis of Chromatic Dispersion (CD) effects on Microwave Photonic Filter (MPF) filters is presented, offering strategies to increase the MPF stopband attenuation. Phased Array Antenna (PAA) are widely extended for wireless communications,radar, radio-astronomy and many other applications, and are also identified as a field that can benefit from photonic technologies, as typical electronic implementations may restrict the usable bandwidth and received power, introduce frequency or bandwidth dependent distortions in the radiation pattern, usually related to issues implementing wide-band true time delays. MWParises as a promising solution whose advantages and disadvantages are elaborated. Looking at more advanced applications of antenna arrays, Aperture Synthesis (AS) is a technique used to recover the brightness distribution observed by an antenna array through interferometric measurements, which has attracted considerable developments in the field of MWP as photonic correlators can provide key advantages. We review the State of the Art of photonic correlators for AS, and develop an alternative implementation of a single baseline photonic correlator which substitutes the optical filtering stage by leveraging CD frequency-to-time mapping. A multiple baseline photonic correlator is also developed, allowing to compute many correlations simultaneously, introducing high scalability and avoiding the pitfalls of other similar developments, such as optical phase stabilization and extremely demanding spatial precision requirements. This multiple baseline photonic correlator has culminated in a patent submission. Our research also deeps in extending the frequency range up to the THz, where Photoconductive Antenna (PCA) based THz Time Domain Spectroscopys (THz-TDSs) stand out as a very popular research platform. However, challenging alignment requirements impact on such systems, typically limiting its use to a single setup configuration (e.g. transmission or reflection spectroscopy setups) and influencing the emission characteristics. Optimization and alignment of a THz-TDS system is deeply addressed, identifying different causes affecting the emitted pulse and its beam characteristics. We develop and test a simple yet powerful method to characterize THz emissions from PCAs, with promising applications for PCA development, THz-TDS imaging, THz Arbitrary Waveform generation (AWG), etc. We apply our method to characterize 12 different PCAs using a meticulous alignment procedure and signal post-processing, with experimental results showing the spatial beam distribution, frequency power spectrum, polarization measurements and Laguerre-Gauss modal analysis. To the best of our knowledge, this represents the larger amount of PCAs characterized in a study. The data obtained with our characterization method is used to demonstrate THz AWG through beam transformations with transmission masks. Modification of THz-TDS is further explored, with different setup configurations developed and analyzed to improve the measurements through customization for different types of samples and measurement requirements, including a THz interferometer.
  

• PORTAL GONZALEZ, GERARD: Synergistic optical and microwave remote sensing approaches for soil moisture mapping at high resolution
  
  Author: PORTAL GONZALEZ, GERARD
  Thesis link: http://hdl.handle.net/10803/675578
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Temporary seizure
  Reading date: 27/05/2022
  Thesis director: VALL-LLOSSERA FERRAN, MERCEDES MAGDALENA | PILES GUILLEM, MARIA
  

  Committee:
       PRESIDENT: ZRIBI, MEHREZ
       SECRETARI: DUFFO UBEDA, NURIA
       VOCAL: MONTZKA, CARSTEN
  Thesis abstract: Soil moisture is an essential climate variable that plays a crucial role linking the Earth¿s water, energy, and carbon cycles. It is responsible for the water exchange between the Earth¿s surface and the atmosphere, and provides key information about soil evaporation, plant transpiration, and the allocation of precipitation into runoff, surface flow and infiltration. Therefore, an accurate estimation of soil moisture is needed to enhance our current climate and meteorological forecasting skills, and to improve our current understanding of the hydrological cycle and its extremes (e.g., droughts and floods). L-band Microwave passive and active sensors have been used during the last decades to estimate soil moisture, since there is a strong relationship between this variable and the soil dielectric properties.Currently, there are two operational L-band missions specifically devoted to globally measure soil moisture: the ESA¿s Soil Moisture and the Ocean Salinity (SMOS), launched in November 2009; and the NASA¿s Soil Moisture Active Passive (SMAP), launched in January 2015. The spatial resolution of the SMOS and SMAP radiometers, in the order of tens of kilometers (~40 km), is adequate for global applications. However, to fulfill the needs of a growing number of applications at local or regional scale, higher spatial detail (< 1 km) is required. To bridge this gap and improve the spatial resolution of the soil moisture maps, a variety of spatial enhancement or spatial (sub-pixel) disaggregation approaches have been proposed.This Ph.D. Thesis focuses on the study of the Earth¿s surface soil moisture from remotely sensed observations. This work includes the implementation of several soil moisture retrieval techniques and the development, implementation, validation and comparison of different spatial enhancement or downscaling techniques, applied at local, regional, and continental scale. To meet these objectives, synergies between several active/passive microwave sensors (SMOS, SMAP and Sentinel-1) and optical/thermal sensors (MODIS) have been explored. The results are presented as follows:- Spatially consistent downscaling approach for SMOS using an adaptive moving windowA passive microwave/optical downscaling algorithm for SMOS is proposed to obtain fine-scale soil moisture maps (1 km) from the native resolution (~40 km) of the instrument. This algorithm introduces the concept of a shape-adaptive window as a central improvement of the disaggregation technique presented by Piles et al. (2014), allowing its application at continental scales. - Assessment of multi-scale SMOS and SMAP soil moisture products across the Iberian PeninsulaThe temporal and spatial characteristics of SMOS and SMAP soil moisture products at coarse- and fine-scales are assessed in order to learn about their distinct features and the rationale behind them, tracing back to the physical assumptions they are based upon.- Impact of incidence angle diversity on soil moisture retrievals at coarse and fine scales An incidence angle (32.5°, 42.5° and 52.5°)-adaptive calibration of radiative transfer effective parameters single scattering albedo and soil roughness has been carried out, highlighting the importance of such parameterization to accurately estimate soil moisture at coarse-resolution. Then, these parameterizations are used to examine the potential application of a physically-based active-passive downscaling approach to upcoming microwave missions, namely CIMR, ROSE-L and Sentinel-1 Next Generation. Soil moisture maps obtained for the Iberian Peninsula at the three different angles, and at coarse and fine scales are inter-compared using in situ measurements and model data as benchmarks.
  

• RAMON MALDONADO, EDUARD: Few-shot 3D reconstruction of body parts with deep neural networks
  
  Author: RAMON MALDONADO, EDUARD
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Temporary seizure
  Reading date: 15/09/2022
  Thesis director: GIRÓ NIETO, XAVIER | GARCIA GIRALDEZ, JAIME | MORENO NOGUER, FRANCESC D'ASSIS
  

  Committee:
       PRESIDENT: BALLESTER NICOLAU, COLOMA MARIA
       SECRETARI: SANCHEZ RIERA, JORDI
       VOCAL NO PRESENCIAL: CASAS GUIX, DAN
  Thesis abstract: In this thesis, we study the problem of reconstructing objects from a concrete category in 3D when few images are available as input, i.e. less than 10. We apply our findings to digitalizing human body parts such as heads and torsos for medical applications.The first part of the thesis explores systems that rely on 3D Morphable Models. When approaching a concrete task, training such systems requires expensive manual hyperparameter tuning of both the architecture and the loss, which is time consuming. We focus on designing novel losses without hyperparameters and modular architectures that allow to train models without tuning efforts. We also aim at providing a fine alignment between the 3D space and the image space by estimating camera poses with a low reprojection error that further improve the texturing process in 3D modelling applications or the rendering process in augmented reality applications. Our findings lead to systems that are very stable and that naturally scale to different scenes. While 3D Morphable Models are fast and robust, they are still very limited in terms of accuracy and expressiveness, which might be prohibitive for applications that require high fidelity. A promising alternative to 3D Morphable Models are implicit functions, which in combination with differentiable rendering techniques have shown impressive results at reconstructing 3D surfaces. However, the later require large sets of images at test time to obtain satisfactory results. In the second part of the thesis, we propose to use a probabilistic model that represents a distribution of implicit surfaces in combination with a differentiable renderer to reduce the number of images required at test time. The resulting 3D reconstruction system is highly accurate and allows to reconstruct a wide variety of human head shapes when only 3 images are available.
  

• RUBINO, ROSELENA: Deriving vertical total electron content maps from SMOS full polarimetric data to compensate the Faraday rotation effect
  
  Author: RUBINO, ROSELENA
  Thesis link: http://hdl.handle.net/10803/675406
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 16/09/2022
  Thesis director: DUFFO UBEDA, NURIA | GONZÁLEZ GAMBAU, VERÓNICA
  

  Committee:
       PRESIDENT: PILES GUILLEM, MARIA
       SECRETARI: VALL-LLOSSERA FERRAN, MERCEDES MAGDALENA
       VOCAL: OLMEDO CASAL, ESTRELLA
  Thesis abstract: The Faraday rotation is a geophysical effect that causes a rotation of the electromagnetic field components emitted by the Earth when it propagates through the ionosphere. It depends on the vertical total electron content (VTEC) of the ionosphere, the geomagnetic field, and the frequency. For satellite measurements at the L band, this effect is not negligible and must be compensated for. This is the case of the Soil Moisture and Ocean Salinity (SMOS) mission, where the measured polarimetric brightness temperature must be corrected from the Faraday rotation effect before the retrieval of the geophysical parameters.The Faraday rotation angle (FRA) can be estimated using a theoretical formulation that makes use of external sources for the VTEC and the geomagnetic field. Alternatively, it can be continuously retrieved from the SMOS full-polarimetric data. However, this is not straightforward due to the relatively poor radiometric sensitivity (thermal noise) and accuracy (spatial bias) of its payload MIRAS (Microwave Interferometer Radiometer by Aperture Synthesis). In this thesis, a methodology for estimating the total electron content of the ionosphere by using an inversion procedure from the measured rotation angle has been developed. These SMOS VTEC maps are derived from SMOS measurements in the Extended Alias-Free Field of View (EAF-FoV) by applying spatio-temporal filtering techniques to mitigate the radiometric errors present in the full-polarimetric measured brightness temperatures. Systematic error patterns found in the Faraday rotation angle retrieval have been characterized along the mission and corrected. The methodology is independent, not only of external databases and forward models, but also of the target that is being measured. Eventually, these SMOS-derived VTEC maps can then be used in the SMOS level 2 processors to improve the geophysical retrievals. The impact of using these SMOS VTEC maps to correct the FRA in the SMOS mission instead of the commonly used VTEC data from GPS has also been assessed, particularly over ocean, where the ionospheric effect is stronger. This assessment has demonstrated improvements in the spatial biases, in the stability of the brightness temperatures (especially in the third Stokes parameter), and in the reduction of the latitudinal gradient present in the third Stokes parameters. All these quality indicators point to a better quality of the geophysical retrievals.
  

• VILÀ MUÑOZ, IRENE: Contribution to the modelling and evaluation of radio network slicing solutions in 5G
  
  Author: VILÀ MUÑOZ, IRENE
  Thesis link: http://hdl.handle.net/10803/674243
  Programme: DOCTORAL DEGREE IN SIGNAL THEORY AND COMMUNICATIONS
  Department: Department of Signal Theory and Communications (TSC)
  Mode: Normal
  Reading date: 06/04/2022
  Thesis director: UMBERT JULIANA, ANNA | SALLENT ROIG, JOSE ORIOL
  

  Committee:
       PRESIDENT: VALDOVINOS BARDAJÍ, ANTONIO
       SECRETARI: GELONCH BOSCH, ANTONIO JOSE
       VOCAL: GIUPPONI, LORENZA
  Thesis abstract: Network slicing is a key feature of 5G architecture that allows the partitioning of the network into multiple logical networks, known as network slices, where each of them is customised according to the specific needs of a service or application.Thus, network slicing allows the materialisation of multi-tenant networks, in which a common network infrastructure is shared among multiple communication providers, acting as tenants and each of them using a different network slice. The support of multi-tenancy through slicing in the Radio Access Network (RAN), known as RAN slicing, is particularly challenging because it involves the configuration and operation of multiple and diverse RAN behaviours over the common pool of radio resources available at each of the RAN nodes. Moreover, this configuration needs to be performed in such a way that the specific requirements of each tenant are satisfied and, at the same time, the available radio resources are efficiently used. Therefore, new functionalities that allow the deployment of RAN slices are needed to be introduced at different levels, ranging from Radio Resource Management (RRM) functionalities that incorporate RAN slicing parameters tofunctionalities that support the lifecycle management of RAN slices. This thesis has addressed this need by proposing, developing and assessing diverse solutions for the support RAN slicing, which has allowed evaluating the capacities, requirements and limitations of network slicing in the RAN from diverse perspectives.Specifically, this thesis is firstly focused on the analytical assessment of RRM functionalities that support multi-tenant and multi-services scenarios, where services are defined according to their 5G QoS requirements. This assessment is conducted through the Markov modelling of admission control policies and the statistical modelling of the resourc allocation, both supporting multiple tenants and multiple services. Secondly, the thesis addresses the problem of slice admission control by proposing a methodology for the estimation of the radio resources required by a RAN slice based on data analytics. This methodology supports the decision on the admission or rejection of new RAN slice creation requests.Thirdly, the thesis explores the potential of artificial intelligence, and specifically, of Deep Reinforcement Learning (DRL) to deal with the capacity sharing problem in RAN slicing scenarios. To this end, a DRL-based capacity sharing solution that distributes the available capacity of a multi-cell scenario among multiple tenants is proposed and assessed. The solution consists in a Multi-Agent Reinforcement Learning (MARL) approach based on Deep Q-Network. Finally, this thesis discuses diverse implementation aspects of the DRL-based capacity sharing solution, including considerations on its compatibility with the standards, the impact of the training on the achieved performance, as well as the tools and technologies required for the deployment of the solution in the real network environment.
  

Last update: 06/10/2022 05:01:04.

Research groups

• ANTENNALAB-Antennas and Wireless Systems Laboratory
• CommSensLab-UPC-Centre Especific de Recerca en Comunicacio i Deteccio UPC
• CSC-Components and Systems for Communications Research Group
• GCO-Optical Communications Group
• GPI-Image and Video Processing Group
• GRCM-Mobile Communication Reserach Group
• RF&MW-Laboratory of RF & microwave systems, devices and materials
• RSLAB-Remote Sensing Lab
• SPCOM-Signal Processing and Communications Group
• VEU-Speech Processing Group
• WiComTec-Wireless Communications and Technologies Research Group

Teachers

• Aguasca Sole, Alberto
• Agusti Comes, Ramon
• Alonso Zarate, Lluis
• Artigas Garcia, David
• Barlabe Dalmau, Antoni
• Belmonte Molina, Aniceto
• Bertran Alberti, Eduard
• Blanch Boris, Sebastián
• Broquetas Ibars, Antoni
• Cabrera Bean, Marga
• Camps Carmona, Adriano Jose
• Casadevall Palacio, Ferran
• Casas Pla, Josep Ramon
• Collado Gomez, J.Carlos
• Comellas Colome, Jaume
• Comeron Tejero, Adolfo
• Corbella Sanahuja, Ignasi
• Dios Otin, Victor Federico
• Duffo Ubeda, Nuria
• Fabregas Canovas, Francisco Javier
• Fernandez Rubio, Juan-Antonio
• Ferrus Ferre, Ramon
• Garcia Lozano, Mario
• Garcia Vizcaino, David
• Gasull Llampallas, Antoni
• Gelonch Bosch, Antoni
• Gene Bernaus, Joan M.
• Gilabert Pinal, Pere Lluis
• Giro Nieto, Xavier
• Gonzalez Arbesu, Jose Maria
• Heldring, Alexander
• Hernando Pericas, Francisco Javier
• Jofre Roca, Lluis
• Junyent Giralt, Gabriel
• Lagunas Hernandez, M. A.
• Lamarca Orozco, Meritxell
• Lazaro Villa, Jose Antonio
• Lopez Martinez, Carlos
• Mallorqui Franquet, Jordi Joan
• Marques Acosta, Ferran
• Mateu Mateu, Jordi
• Monte Moreno, Enric
• Montoro Lopez, Gabriel
• Moreno Bilbao, M. Asuncion
• Morros Rubio, Ramon
• Muñoz Medina, Olga
• Nadeu Camprubi, Climent
• Najar Marton, Montse
• O'callaghan Castella, Joan
• Olmos Bonafe, Juan Jose
• Pages Zamora, Alba
• Pardas Feliu, Montse
• Pascual Iserte, Antonio
• Perez Neira, Ana Isabel
• Perez Pueyo, Rosanna
• Perez Romero, Jordi
• Perez Torres, Juan
• Pradell Cara, Lluis
• Prat Goma, Josep
• Rey Micolau, Francesc
• Riba Sagarra, Jaume
• Rius Casals, Juan-Manuel
• roca cl,
• Rocadenbosch Burillo, Francisco
• Rodriguez Fonollosa, Javier
• Rodriguez Fonollosa, Jose Adrian
• Rodriguez Gomez, Alejandro
• Romeu Robert, Jordi
• Ruiz Boque, Silvia
• Ruiz Costa-Jussa, Marta
• Ruiz Hidalgo, Javier
• Ruiz Moreno, Sergio
• Sala Alvarez, Josep
• Salembier Clairon, Philippe
• Sallent Roig, Jose Oriol
• Santos Blanco, María
• Sicard, Michaël
• Soneira Ferrando, M. Jose
• Spadaro, Salvatore
• Tarres Ruiz, Francisco
• Torner Sabata, Lluis
• Torres Torres, Francesc
• Torres Urgell, Luis
• Ubeda Farre, Eduard
• Valenzuela Gonzalez, Jose Luis
• Vall-Llossera Ferran, Mercè
• Vazquez Grau, Gregori
• Vidal Manzano, Josep
• Vilaplana Besler, Veronica
• Villares Piera, Nemesio Javier