proceedingsmaptele2016/wp-content/uploads/map...experiment which used a plane to survey a given area...

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Altice Labs

Bosch

Compta

IBM

Ubiwhere

A world of Internet of Things and Big Data

Discussion Panel:

Keynote Speech Adopting nature inspired techniques in solving

communication problems

Professor Andreas Pitsillides

University of Cyprus

4 oral presentation sessions

1 poster session

PROCEEDINGS

1

Workshop Programme

08:30 - 09:00

09:00 - 09:30

José Quevedo Local Domain Service Discovery for ICN-based IoT environments

Daniel Malafaia Spatial Spectrum Sensing

Mário Sousa Passive Synthetic Aperture Radar Using Signals of Opportunity

10:15 - 10:45

Iman Kianpour Design of a Low-Power Transmitter for UWB Applications

Bilal Hussain RFID based IR-UWB Receiver for WSN Applications

Samaneh Moeini Homogenization of Spatially Dispersive 1D Fractal Metamaterials

12:30 - 14:00

Syed Ali Joint IA and SFBC Macro and Small-cells Coexistence under Minor Information Exchange

João Almeida Dependable Wireless Communications for Infrastructure-based Vehicular Networks

Filipe Sousa Green Wireless Video Sensor Networks using a Low Power Radio System as Control Channel

Diogo Ferreira C4S - Coding for Speed

Alireza Esfahani Security Mechanism Against Pollution Attacks in Network Coding over Wireless Networks

Ana Bastos Development of a Low Cost Coherent Receiver

Cátia Pinho Spatial Light Modulation for SDM systems

Cristiano Pendao Self (re)generated radio maps

Daniel Dinis Tunable Delta-Sigma Modulator for Agile All-Digital Transmitters

Mário Ferreira Dynamically Reconfigurable FFT Processor for Flexible OFDM Baseband Processing

15:45 - 16:00

Filipe Teixeira Sub-GHz Underwater IEEE 802.11 Networks using Software Defined Radios

Oluyomi Aboderin Antenna for Underwater Application

Isiaka Alimi Optical Wireless Communication for Future Broadband Access Networks

Sofia Amado Digital Equalization for Optical Coherent Transmission Systems

18:00 - 18:30

18:30 - 19:15 GET TOGETHER (PORTO D'HONRA)

A world of Internet of Things and Big Data

Chair: Prof. José Vieira (U. Aveiro)

KEYNOTE SPEAKER

LUNCH BREAK

ORAL PRESENTATIONS SESSION III: WIRELESS NETWORKS & NETWORK CODINGChair: Prof. Rui Aguiar (U. Aveiro)

POSTER SESSION

COFFEE BREAK

ORAL PRESENTATIONS SESSION IV: UNDERWATER & OPTICAL COMMUNICATIONSChair: Luís Pessoa (INESC TEC)

DISCUSSION PANEL

CLOSING SESSION

REGISTRATIONS

OPENING SESSION

ORAL PRESENTATIONS SESSION I: IoT & RF APPLICATIONSChair: Prof. José Machado da Silva (U. Porto)

COFFEE BREAK

15:15 - 15:45

16:00 - 17:00

17:00 - 18:00

ORAL PRESENTATIONS SESSION II: ANTENNAS & MATERIALS

09:30 - 10:15

10:45 - 11:30

11:30 - 12:30

14:00 - 15:15

Moderator: Prof. Rui Aguiar (U.Aveiro) Panelists: Altice Labs, Bosch, Compta, IBM, Ubiwhere

Professor Andreas Pitsillides - Adopting nature inspired techniques in solving communication problems

2

MAP-Tele Doctoral Programme

The MAP-tele Doctoral Programme in Telecommunications is a joint venture of University of

Minho, University of Aveiro and University of Porto, three Portuguese Universities with a

strong tradition in the area of Telecommunications Engineering. The programme represents a

fusion of the doctoral offers in Telecommunications in the three institutions and constitutes a

unified effort to prepare highly qualified human resources in Telecommunications. The

programme is supported by an academic staff of more than 150 PhDs whose research and

development activities covers a wide range of topics, ranging from theoretical and fundamental

aspects to the experimental and applied areas of Telecommunications, and comprehends wide-

ranging collaborative work with leading industries in this country and abroad. The MAP-tele

Doctoral Programme in Telecommunications targets both national and international audiences

and is designed for excellence and competitiveness at the international level. It aims to prepare

selected students for leadership in research and development careers in industry, academia and

independent entrepreneurial initiatives.

The MAP-tele Workshop is organized by MAP-tele first year students and intends to attract

original, pertinent and relevant contributions on the technological, organizational and

management dimensions of the largely multidisciplinary field of Telecommunications and

Information Systems and Technologies.

Submissions to the workshop are mandatory for MAP-Tele PhD students. Specifically, Second-

year students present their work as a Poster and Third-year (and above) students as Oral

presentations. Research centres affiliated with the three Universities (IT, IEETA, FSCOD,

INESC TEC, LIACC, Centro Algoritmi, CCTC) as well as leading companies associated with

the programme are also invited to present their work at the Workshop.

This year's edition (9th edition) of the MAP-tele Workshop is hosted by Faculdade de

Engenharia da Universidade do Porto on 4th May, 2016.

Organization Team

(All of Faculty of Engineering, University of Porto)

Workshop Chairs Logistics Committee:

Orangel Contreras Celestino Martins

Eduardo Almeida Emanuel Lima

Communications Committee Scientific Committee

Eduardo Almeida Joana Tavares

Joana Tavares Eduardo Almeida

Asad Rehman Sherif Busari

Stephen Ogodo

Steering Committee

Prof. Aníbal Ferreira, Faculty of Engineering, University of Porto

Prof. Henrique Salgado, Faculty of Engineering, University of Porto

3

Keynote Speech

Adopting nature inspired techniques in solving communication problems

Professor Andreas Pitsillides

University of Cyprus

Abstract

This talk will firstly motivate nature inspired techniques in addressing communication

problems. Such techniques normally involve specifying a set of simple rules, observed by the

behaviour of simple organisms which adhere to those rules, and a method of iteratively

applying those rules in real communication problems, collectively achieving global properties

as a result of evolutionary design. When these simple entities (agents) operate in an

environment, an emergent behaviour, or emergent property, can appear, forming more complex

behaviors as a collective, displaying inherent powerful characteristics with global self-*

properties (as e.g. self-organization and self-adaptation). These self-* properties are not

programmed explicitly into individual entities, but emerge as a result of the design of the nature

inspired model.

Three diverse illustrative approaches for its application will be demonstrated:

1. Bird flocking. The obstacle avoidance behavior of bird flocks for congestion control

in wireless sensor networks (WSNs)—in some detail

2. Quorum sensing: addressing information dissemination in biological nanonetworks

inspired by the quorum sensing process which bacteria employ for synchronized

action based on population density measurements.

3. Competition of species: Competitive coexistence behavior of species sharing some

limiting resource for streaming applications in WSNs

Finally, the talk will close with some concluding remarks.

Speaker Biography

Andreas Pitsillides is a Professor in the Department of Computer Science, University of

Cyprus, and heads the Networks Research Laboratory (NetRL,

http://www.NetRL.cs.ucy.ac.cy), which he founded in 2002. Andreas is also a Founding

member and Chairman of the Board of the Cyprus Academic and Research Network (CYNET)

since its establishment in 2000. Since May 2014 Andreas was also appointed Visiting Professor

at the University of Johannesburg, Department of Electrical and Electronic Engineering

Science, South Africa. His research interests include communication networks (fixed and

mobile/wireless), the Internet- and Web- of Things, Smart Spaces (Home, Grid, City), and

Internet technologies and their application in Mobile e-Services, especially e-health, and

security. He has a particular interest in adapting tools from various fields of applied

http://www.ucy.ac.cy/en/

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mathematics such as adaptive non-linear control theory, computational intelligence, game

theory, and recently complex systems and nature inspired techniques, to solve problems in

communication networks. Published over 230 referred papers in flagship journals (e.g. IEEE,

Elsevier, IFAC, Springer), international conferences, and book chapters, he is the co-author

with Josephine Antoniou of the book Game Theory in Communication Networks: Cooperative

Resolution of Interactive Networking Scenarios (CRC, ISBN: 978-1439848081, 2012), he is

the co-editor with Petros Ioannou of the book on Modelling and Control of Complex Systems

(CRC Press, ISBN: 978-0-8493-7985-0, 2007), participated in over 30 European Commission

and locally funded research projects with over 4.5 million Euro as principal or co-principal

investigator, presented keynotes, invited lectures at major research organisations, short courses

at international conferences and short courses to industry. He serves on the editorial boards of

the Journal of Computer Networks (COMNET) and International Journal of Handheld

Computing Research (IJHCR), serves/served on international conferences as General Chair

(ISSPIT 2016, ISCC2015, MedHocNet2012, ICT2011, EuroMedNet’98), Vice General Chair

(WiOpt’07), international co-chair (INFOCOM 2003), technical program chair (MCCS05,

ISYC06), and on executive committees (e.g. INFOCOM 2001–2003, and ICT98), technical

committees, guest co-editor, invited speaker, and as a regular reviewer for conference and

journal submissions. He is also a member of the International Federation of Automatic Control

(IFAC) Technical Committee (TC 1.5) on Networked Systems, IFAC TC 7.4 on Transportation

Systems and the IFIP working group WG 6.3.

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Abstracts (Oral Presentations)

Local Domain Service Discovery for ICN-based IoT environments

José Quevedo, Carlos Guimarães, Rui Ferreira, Daniel Corujo, Rui L. Aguiar

University of Aveiro | Instituto de Telecomunicações – Aveiro

Information Centric Networking (ICN) is an emerging research topic aiming at shifting the

Internet from its current host-centric paradigm towards an approach centred around content,

which enables the direct retrieval of information objects in a secure, reliable, scalable, and

efficient way. The exposure of ICN to scenarios other than static content distribution is a

growing research topic, promising to extend the impact of ICN to a broader scale. In this

context, particular attention has been given to the application of ICN in Internet of Things (IoT)

environments. The current work, by focusing on local domain IoT scenarios, discusses the

challenges that ICN, particularly Interest-based solutions, impose to service discovery. This

work proposes a service discovery mechanism for such scenarios, relying on an alternative

forwarding pipeline for supporting its core operations. The proposed mechanism is validated

through a proof-of-concept prototype, developed on top of the Named Data Networking (NDN)

ICN architecture, with results showcasing the benefits of our solution for discovering services

within a collision domain.

Spatial Spectrum Sensing

Daniel Malafaia, José Vieira, Ana Tomé

University of Aveiro | IEETA

In the last few years, there has been significant progress in the development of Spectrum

Sensing methods. In this presentation, we will explore the current interest in Spatial Spectrum

Sensing, due to the increasing trend on MIMO techniques in wireless communications to

increase spectral efficiency. Thus, future deployments of cognitive radios will have to consider

not only traditional Spectrum Sensing methods for detection of non-occupied frequency bands,

but can also determine each transmission's direction of arrival, allowing then for spatial reuse

of the same frequency band.

Passive Synthetic Aperture Radar Using Signals of Opportunity

Mário Martins de Sousa, Sérgio Reis Cunha

Faculty of Engineering, University of Porto | INESC-TEC

Synthetic Aperture Radar (SAR) is a method of producing images of a given target scene by

coherently combining a set of received echoes of a transmitted RF signal. It also relies on the

relative motion between the receptor and the target to achieve a synthetically higher aperture

than conventional beam scanning radars. This allows to produce high resolution images which

can even show objects behind other objects. SAR imaging is very useful in applications such

as topography, law enforcement and warfare scenarios. The use of passive systems is of

particular relevance for airborne applications, especially performing autonomously, requiring

low power consumption and stealth. Nowadays, two examples of signals of opportunity which

are spectrally rich and well-shaped, widely available and provide precise reconstruction are

those from digital television broadcast (DVB-T) and from cellular networks (LTE). This PhD

work concerns the use of signals of opportunity for airborne SAR applications. In order to

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evaluate the feasibility of such concept, the authors present the results of a developed

experiment which used a plane to survey a given area illuminated by DVB-T signals. The

reflection of these signals were recorded during the flight and post-processed to produce the

corresponding image.

Design of a Low-Power Transmitter for UWB Applications

Iman Kianpour, Vitor G. Tavares, Helio S. Mendonca


Sensor networks are key enablers of IoT. Autonomy is crucial for keeping these systems

running with minimal human intervention. In this context, the aim of this doctoral research

work is to devise a novel transmitter for IoT applications that uses a different form of signal

encoding/modulation, to naturally fit impulse-radio ultra wide-band (IR-UWB) technology.

Significant improvement on average power consumption is expected. The modulation is based

on integration-and-fire (I&F) mechanisms, which reduce the complexity of the circuit and

therefore decreases the total needed energy. A few circuits were fabricated and measured

during the past period, which include an operational transconductance amplifier (OTA) and a

UWB pulse generator. A printed circuit board (PCB) has been designed and fabricated for

testing purposes, where the designed chip was wire-bonded. Testing is still underway, but the

preliminary assessments show that the results are as expected. The matching is within the

desired range and the output central frequency was controllable by the tuning voltage. During

last year a couple of papers were published reporting the research achievements, and presently

a journal paper has been written and a few more are being planned for the near future.

RFID based IR-UWB Receiver for WSN Applications

Bilal Hussain, Vitor Grade Tavares, Helio Mendonca


This doctoral work mainly focuses on the receiver implementation of batteryless RFID based

IR-UWB receiver for WSN applications. Low noise amplifier (LNA) presents a pivotal role in

the proposed receiver chain. The low cost requirement suggests the use of CMOS technologies

for mass production. Current CMOS processes are quite mature for technologies operating at

less than 5GHz. But above this frequency, noise properties of silicon devices are not attractive

for low noise applications. For current doctoral proposal, 130nm UMC technology was chosen

for device fabrication. Initially a cascaded low noise amplifier was designed for whole UWB

range and the measurements suggest that the technology is suitable for designing UWB low

noise amplifiers. To achieve a lower noise figure, a novel technique of capacitive feedback is

applied. The simulation results show a NF of -3dB with a gain of 16dB for whole UWB range.

Such a LNA is sufficient for implementation of aforementioned pulse detection receiver

topology. Antenna is also one of the key components in transceiver chain. The wide bandwidth

of UWB systems call for a wide band antenna with acceptable size for WSN applications. In

order to reduce the size, high permittivity based substrates were investigated. As the sensors

for the concerned project was built in Low Temperature Co-fired Ceramics (LTCC), similar

substrate was used for antenna design. The fabricated antenna shows promising results for

application in UWB frequency range [2]. Also other substrates such as Kapton (mostly used in

flexible electronics) are also investigated for UWB applications.

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Homogenization of Spatially Dispersive 1D Fractal Metamaterials

Samaneh Moeini, José Carlos Pedro


Since the introduction of metamaterials into the area of microwave electromagnetics,

metamaterials have been employed in a variety of prospective microwave devices such as

antennas, filters, phase shifters, etc. Metamaterials are typically periodic structures. In this

work, the focus is on fractal structures.

Fractal electrodynamics has a proved value in antenna and high frequency designs, as has been

demonstrated by previous studies. Here, we formulate a theoretical fractal geometric-approach

to a 1D-metamaterial design and develop appropriate homogenization methods. Fractal

structures generally require a special treatment, as will be demonstrated in this presentation.

Particularly, we consider a metamaterial formed by a set of dielectric layers of varying

permittivity and thickness, distributed along the z-axis according to a one-dimensional fractal

set. The whole structure is infinite (as compared to the operating wavelength) and uniform

along the y and x axes, and is either finite or periodic along the z-axis, comprising one fractal

unit per period.

In order to extract the effective dispersive permittivity of this medium as a function of the

frequency and the wave vector understood as independent variables, the structure is excited by

an embedded source. The fields are obtained analytically and also numerically by using an

FDTD algorithm. We test the performance of the method by comparing the extracted

permittivity with a previously obtained expression for the same quantity in the quasi-static

limit.

Joint IA and SFBC Macro and Small-cells Coexistence under Minor Information

Exchange

Syed Saqlain Ali, Daniel Castanheira, Adão Silva, Atílio Gameiro


The deployment of small-cells within the boundaries of a macro-cell is considered to be an

effective solution to cope with the current trend of higher data rates and improved system

capacity. In the current heterogeneous configuration with the mass deployment of small-cells,

it is preferred that these two cell types will coexist over the same spectrum, because acquiring

additional spectrum licenses for smallcells is difficult and expensive. However, the coexistence

leads to cross-tier/intersystem interference. In this context, this contribution investigates

interference alignment (IA) methods in order to mitigate the interference of macro-cell base

station towards the small-cell user terminals. More specifically, we design a diversity-oriented

interference alignment scheme with space-frequency block codes (SFBC). The main

motivation for joint interference alignment with SFBC is to allow the coexistence of two

systems under minor inter-system information exchange. The small-cells just need to know

what space-frequency block code is used by the macro-cell system and no inter-system

channels need to be exchanged, contrarily to other schemes recently proposed. Numerical

results show that the proposed method achieves a performance close to the case where full-

cooperation between the tiers is allowed.

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Dependable Wireless Communications for Infrastructure-based Vehicular Networks

João Miguel Pereira de Almeida, Arnaldo S. R. Oliveira, Joaquim Ferreira


Wireless vehicular networks for cooperative Intelligent Transportation Systems (ITS) support

collaborative applications that can improve vehicle and road safety, passenger's comfort and

efficiency of traffic management. Some of these applications are safety critical and have tight

timeliness and throughput requirements. Despite the obvious potential benefits of vehicular

communications, the design of dependable vehicular networks is a research challenge, due to

the high speed mobility and the open nature of such networks. The presence of a road-side

infrastructure and a backhauling network, adds a degree of determinism that is useful to enforce

real-time and dependability, both by providing global knowledge and supporting the operation

of collision-free medium access control (MAC) protocols. In order to guarantee the

deterministic operation of such protocols, a fault-tolerant infrastructure-based network

architecture was proposed, which includes the development of a fail silence mechanism and an

active replication scheme for the road-side units (RSUs) of vehicular networks and the design

of medium guardians for the on-board units (OBUs) placed inside the vehicles. The proposed

fault-tolerant techniques targeted the integration with a real-time MAC protocol named

Vehicular Flexible Time Triggered (V-FTT). It should be noticed however, that the designed

mechanisms are protocol independent and can be employed in other wireless communications

domains.

Green Wireless Video Sensor Networks using a Low Power Radio System as Control

Channel

Filipe Sousa, Manuel Ricardo, Rui Campos


Nowadays, Internet of Things (IoT) is already a reality because the low price of connected

devices. Moreover, the huge availability of low cost IP cameras with IEEE 802.11 connection

makes Wireless Video Sensor Networks (WVSNs) widespread. However, WVSNs suffer from

three problems: bad performance, throughput unfairness, and energy inefficiency. To overcome

these problems we propose an holistic solution, LPR-WiFIX, which is based on a low power

radio, used as out-of-band control channel to signal when a video sensor should wake the IEEE

802.11 interface, thus saving energy. The results obtained during the simulation of random

mesh topologies, with networks sizes ranging from 10 to 30 nodes, prove that our solution can

achieve gains up to 50 %, and maintain the levels of performance and throughput fairness.

C4S - Coding for Speed

Diogo Ferreira, Joao Barros, Rui A. Costa, J. Almeida

Faculty of Engineering, University of Porto | Instituto de Telecomunicações – Porto

As the digital revolution evolves, wireless communications have taken a central role in the

information age. The most recognizable sign of this evolution is the fact that nearly 4 billion

WiFi-enabled devices are spread around the world and which enable a multitude of services.

Many of these services would benefit from the existence of communication protocols that

ensure reliable and high throughout data delivery, providing fast transfer of files, whether for

a faster access of consumers to content or a reduction of idle times in uploading and sharing

contents through the cloud or other channels. Traditional transport layer protocols such as TCP

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are commonly used to transfer such files, albeit their inadequacy both to wireless

communications and high-speed networks, due to the poor performance of TCP in the presence

of packet losses, (uplink and downlink), network end-to-end latency, jitter and packet

reordering. The present work proposes new flow and congestion control algorithms based on

network coding principles that provides a faster protocol to transmit files over channels with

any characteristics, by creating a UDP pipe, where network coding is used to ensure reliability.

Results obtained over a large real world test program, with 51 users from 18 countries, showed

that the proposed solution outperforms TCP with average improvements of 2.5 times over WiFi

and 4.3 times over 4G.

Security Mechanisms against Pollution Attacks in Network Coding over Wireless

Networks Alireza Esfahani, Jonathan Rodriguez, Jose Carlos Neves


Recent research efforts have shown that Wireless Networks can benefit from Network Coding

technology in terms of bandwidth, robustness to packet losses, delay and energy consumption.

However, Network Coding-enabled Wireless Networks are susceptible to a severe security

threat, known as data pollution attack, where a malicious node injects into the network polluted

packets that prevent the destination nodes from decoding correctly. Due to re-coding, occurred

at the intermediate nodes, according to the core principle of Network Coding, the polluted

packets propagate quickly into other packets and corrupt bunches of legitimate packets leading

to network resource waste. Hence, a lot of research effort has been devoted to schemes against

data pollution attacks. One of the most well-known scheme is Homomorphic Message

Authentication Code (HMAC). However, HMAC schemes are susceptible to a new type of

pollution attack, called tag pollution attack, where an adversary node randomly modifies tags

appended to the end of the transmitted packets. Therefore, in this thesis, we propose four

efficient Homomorphic Message Authentication Code-based schemes, providing resistance

against data pollution attacks and tag pollution attacks in Network Coding-enabled Wireless

Networks. Our results show that the proposed HMAC schemes are more efficient compared to

other competitive tag pollution immune schemes in terms of complexity, communication

overhead and key storage overhead.

Sub-GHz Underwater IEEE 802.11 Networks using Software Defined Radios

Filipe B. Teixeira, Manuel Ricardo, Rui Campos


Enabling underwater broadband communications is crucial for the operation of underwater

vehicles such as Autonomous Underwater Vehicles (AUVs) and Remotely Operated Vehicles

(ROVs). Radio Frequency (RF) communications may overcome the low bandwidth of acoustic

communications and the line of sight requirement of optical networks, but suffer from high

attenuation underwater. Using sub-GHz frequencies increases the range of IEEE 802.11

networks underwater, providing a cost-effective broadband solution for underwater scenarios.

In our work we evaluated the performance of IEEE 802.11 networks underwater at different

sub-GHz frequencies using Software-defined radio platforms. The evaluation was performed

considering frequencies from 70-700 MHz in a large-scale freshwater tank and in real seawater

conditions in the Tagus river estuary. Results show sub-GHz IEEE 802.11 networks can

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operate at 5 m range in freshwater and 1.8 m in seawater, with bitrates up to 550 kbit/s and

delays under 45 ms. These results show the potential of IEEE 802.11 networks for large data

transfer underwater environments, such as live video or image.

Antenna for Underwater Application

Oluyomi Aboderin, Luís Pessoa, Henrique Salgado


The capability of relatively high-speed short-range communications of Autonomous

Underwater Vehicles (AUVs) or Remote Operated Vehicles (ROVs) in underwater scenarios,

for example, for communication between vehicles or when approaching a docking station for

downloading of data gathered during a survey mission, is becoming a relevant application, in

the context of sea exploration and mining.

In this paper, the performance of three antennas, specifically, loop, dipole and J-pole is assessed

through simulation for usage in fresh and sea water and operating in the High Frequency (HF)

band. The antennas are compared in terms of bandwidth and directivity.

The antennas were designed with FEKO electromagnetic simulation software and the results

show that these antennas will be desirable for either short distance communication with higher

bandwidth and higher data rates or long distance communication with lower data rates.

Optical Wireless Communication for Future Broadband Access Networks

Isiaka Alimi, Paulo Monteiro and António Teixeira


We present experimental results on ergodic channel capacity of single input single output

(SISO) free-space optical (FSO) communication link. Furthermore, we present simulation

results on bit error rate (BER) performance of M-QAM considering the average received

irradiance. In the simulation, effects of different parameters such as constellation size,

wavelength and the refractive index which can be helpful in the adoption of adaptive

modulation scheme are analyzed on system performance for different operating conditions.

Digital Equalization for Optical Coherent Transmission Systems

Sofia B. Amado, Fernando P. Guiomar, Nelson J. Muga, Armando N. Pinto


Nowadays, advanced modulation formats, together with coherent detection and digital signal

processing have been attracting significant attention. The coherent systems allow the retrieval

of the signal amplitude and phase information to the electrical domain, making possible to

efficiently equalize the system transmission impairments in the digital domain. However, the

real-time implementation of the digital signal processing algorithms represents a major

challenge for the coherent optical transmission systems.The low sampling rate of the available

analog to digital converters and the limited resources of the development platforms has been

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leading to the increasing research effort on the development and optimization of digital signal

processing subsystems. Thus, becomes important to develop low complexity algorithms to

allow its hardware implementation.

The real time implementation of a coherent transmission system operating at lower bit rates

(< 2.5Gb/s) has been successfully demonstrated and the computational resources of each digital

signal processing algorithm were quantified for low and high bit rates. New optical

transmission techniques, together with low complexity digital algorithms for the nonlinear and

chromatic dispersion equalization, have been proposed and experimentally validated in offline

and real-time.

Abstracts (Posters)

Tunable Delta-Sigma Modulator for Agile All-Digital Transmitters

Daniel António da Costa Dinis, Arnaldo Oliveira, José Neto Vieira


Fully digital transmitters have been pointed out as possible architectures to develop a novel

type of agile, reconfigurable, multi-band, multi-standard and highly-efficient RF transmitters.

Promising architectures have been proposed in the literature with the aim of having full support

for the whole transmitter chain built inside a single chip. However, as far as agility and

reconfigurability are concerned, current state-of-the-art approaches continue to be very

restrictive, hindering their fully acceptance throughout the whole academic and industrial

community. In this sense, a new architecture suitable for designing agile RF fully digital

transmitters either in single- or dual-band scenarios is proposed. Its core is based on a simple

tunable delta-sigma modulator which can be real-time configured as a Low-pass, a Band-Pass

with tunable center frequency or a High-Pass modulator, achieving gains in terms of flexibility

and reconfigurability. Moreover, a 2-path polyphase decomposition was also developed in

order to optimize some figures of merit, such as SNR and EVM, and for demonstrating the

scalability of this type of modulator. This proposed architecture has been successfully

implemented and validated on an FPGA-based transmitter for both single- and dual-band

scenarios.

Spatial Light Modulation for SDM systems

Cátia Pinho, Mário Lima, António Teixeira


Spatial division multiplexing (SDM) systems are essential to overcome the increasing demand

for higher bandwidth data services. Nevertheless, SDM employment is challenging and

complex impairments need to be addressed (e.g., crosstalk and nonlinearities). The application

of spatial light modulation (with a spatial light modulator – SLM), in core/mode division

multiplexing is foreseen to improve channel compensation. SLM based on liquid crystal on

silicon technology allow a pixel-by-pixel arbitrarily adjustment of the phase-front of a beam in

a reconfigurable way, being used as a diffractive device to reconstruct images from computer

generated holograms (CGHs).

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Setup deployment and correct alignments in these systems are critical. Therefore, first was

implemented a visible setup and after extrapolated for infrared. The iterative Fourier transform

algorithm was implemented to produce the CGHs.

Holograms were successful generated with the visible transmission SLM and the infrared

refractive SLM. Nonetheless, further improvements in the setup alignments and CGH

algorithm need to be developed to allow the generation of more precise holograms, essential to

address the dimensions of SDM fibres. These preliminary results are a first step for the effective

implementation of spatial light modulation techniques to optimize transmission in SDM

systems.

Self (re)generated radio maps

Cristiano Pendao, Adriano Moreira

University of Minho | Algoritmi Research Center

Radio Maps for scene-analyses techniques, such as Wi-Fi fingerprinting, have been explored

to provide positioning in indoor spaces, but normally rely on manual site survey, known as

calibration phase. The calibration phase has to be repeated periodically to maintain the radio

maps quality, as the radio environment changes, compromising the scalability.

This research aims to fully automate the construction and maintenance of radio maps, using

personal smartphones in a collaborative approach, eliminating the manual calibration phase,

and enabling large scale indoor and outdoor applications.

The radio maps are created iteratively, the combination of dead reckoning and data fusion

techniques, using WLAN radio and motion data collected by smartphones. This radio

maps may be used in different contexts: to map WLAN networks radio interference and to

enable indoor/ outdoor positioning.

Wireless LAN networks deployments are normally unplanned and uncontrolled, resulting in

low communications quality due to interference. Additionally, energy is wasted by unnecessary

overlapping. This radio maps can be used to identify areas with interference, and improve

energy efficiency. Ongoing work is focused on the development of a software module to

generate synthetic radio and motion data from an indoor space covered by a WiFi network, in

a configurable and realistic way.

Dynamically Reconfigurable FFT Processor for Flexible OFDM Baseband Processing

Mário Lopes Ferreira, Amin Barahimi, João Canas Ferreira


The Physical layer architectures for the next generation of wireless devices will be

characterized by a high degree of flexibility for real-time adaptation to communication

conditions variability. OFDM-based architectures are strong candidates for the Physical layer

implementation in 5G systems and one of the most important baseband processing operations

required by this waveform is the Fast Fourier Transform (FFT). This paper proposes a

dynamically reconfigurable FFT processor supporting FFT sizes and throughputs required by

the most widely used wireless standards. The FFT reconfiguration was achieved by means of

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FPGA-based Dynamic Partial Reconfiguration (DPR) techniques, which enables run-time FFT

size adaptation according to communication requirements and better resource utilization. The

impact of DPR in terms of reconfiguration time and power consumption overhead was

evaluated. The obtained results encourage the exploitation of DPR techniques to implement

reconfigurable hardware infrastructures for OFDM baseband processing engines.

Development of a Low Cost Coherent Receiver

Ana Bastos, Carlos Vicente, Luís D. Carlos, Mário Lima, Paulo S. André, Rute A.S. Ferreira


The volume of communication traffic is exploding, due to ever increasing subscriber numbers

and the rise of multimedia based applications [1]. Future disruptive solutions to cope with the

increase bandwidth are based on coherent Passive Optical Network (PON) technology, which

is characterized by the absence of active equipment between subscribers and the operator

location, thereby representing a significant breakthrough in the architecture of an fibre network.

One of the coherent PON solution is the coherent optical system that uses multilevel

modulation formats, like the quadrature phase shift keying (QPSK). This modulation format

utilizes the transmission of phase information instead of amplitude modulation, requiring an

integrated QPSK receiver. The receiver allows the I and Q phase components of the signal to

be extracted as a result of the interference generated by a local oscillator. Taking this into

account, this work proposes a coherent receiver based on flexible organic-inorganic hybrids

for low cost photonic integrated circuits. The organic-inorganic hybrid is UV self-patterned

without the need of photo initiators, enabling the fabrication of PICs using direct-UV laser

writing, and reducing the production cost.

[1] A. Bogoni, "Photonics for Solving Unbundling in Next-Generation WDM-PON," IEEE

Journal of Selected Topics in Quantum Electronics, vol. 17, pp. 472-479,

proceedingsmaptele2016/wp-content/uploads/map...experiment which used a plane to survey a given area...

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