Bart Scheers

Royal Military Academy · Department of Communication, Information, Systems and Sensors (CISS)

In this paper a summary is given of the ongoing research at the Belgian Royal Military Academy in the field of mobile ad hoc networks in general and wireless sensor networks (WSNs) in particular. In this study, all wireless sensor networks are based on the physical and the medium access layer of the IEEE 802.15.4 low rate wireless personal area net...

Neutralizing a drone using a protocol-aware RF jammer requires precise knowledge of the occupied spectrum in the time and frequency domains. This paper aims to develop an automatic spectrum prediction framework utilizing the Convolutional Neural Network (CNN) and Long Short Term Memory (LSTM) models. We generate a synthetic dataset using the common...

Despite several beneficial applications, unfortunately, drones are also being used for illicit activities such as drug trafficking, firearm smuggling or to impose threats to security-sensitive places like airports and nuclear power plants. The existing drone localization and neutralization technologies work on the assumption that the drone has alre...

Despite several beneficial applications, unfortunately, drones are also being used for illicit activities such as drug trafficking, firearm smuggling or to impose threats to security-sensitive places like airports and nuclear power plants. The existing drone localization and neutralization technologies work on the assumption that the drone has alre...

Despite several beneficial applications, unfortunately, drones are also being used for illicit activities such as drug trafficking, firearm smuggling or to impose threats to security-sensitive places like airports and nuclear power plants. The existing drone localization and neutralization technologies work on the assumption that the drone has alre...

Detecting UAVs is becoming more crucial for various industries such as airports and nuclear power plants for improving surveillance and security measures. Exploiting radio frequency (RF) based drone control and communication enables a passive way of drone detection for a wide range of environments and even without favourable line of sight (LOS) con...

Video display units (VDUs) using differential signaling technology significantly increase the risk of compromising video information security through leakage emissions. This article shows that differential signaling cables act as substantial video leakage sources. A concept is proposed that explains the video leakage principles of VDUs using differ...

One of the problems that we face today is the illegal use of drones. Monitoring the RF transmissions has proved to bea reliable technique for detecting and identifying such devices. Although there are some solutions on the market for detection and jamming, they are not always successful. The aim of this paper is to analyze the typical communication...

This paper deals with the jamming attack which may hinder the cognitive radio from efficiently exploiting the spectrum. We model the problem of channel selection as a Markov decision process. We propose a real-time reinforcement learning algorithm based on Q-learning to pro-actively avoid jammed channels. The proposed algorithm is based on wideband...

Making use of reliable and precise location and tracking systems is essential to save firefighters lives during fire operations and to speed up the rescue intervention. The issue is that Global Navigation Satellite System (GNSS) (e.g., GPS and Galileo) is not always available especially in harsh wireless environments such as inside buildings and in...

This paper proposes a method that reconstructs the original video data signal from leaking electromagnetic emanations of multiple video signal sources using a software-defined radio (SDR). The results of the method give valuable insights into the potential risk of this threat of obtaining sensitive information in an everyday situation. The leaking...

Information processing equipment (IPE) inevitably leaks emissions into the far- and near-field. Most of these leaked emanations originate from logical processes of the IPE itself. Hence by capturing these emanations, sensitive information can be passively obtained without needing physical access to the device. In this research paper, a method is pr...

Since the jamming attack is one of the most severe threats in cognitive radio networks, we study how Q-learning can be used to pro-actively avoid jammed channels. However, Q-learning needs a long training period to learn the behaviour of the jammer. We take advantage of wideband spectrum sensing to speed up the learning process and we take advantag...

Belgian RSTD SIC-10 study • Study, develop and implement waveforms for cognitive radio ad-hoc networks • The concept of software defined radios (SDR) is to replace special analog hardware components by field programmable gate arrays (FPGA), digital signal processors (DSP) and general purpose processors (GPP) • Allow fast-prototyping and support mul...

The principal objective of the NATO Narrow Band Waveform (NBWF) is to achieve coalition interoperability within lower tactical levels. This paper describes a low-complexity generic receiver for the different modes of the NBWF. The NBWF burst consists of a continuous wave (CW) signal followed by a pseudo-random sequence and a data sequence modulated...

In this paper, we study the power allocation problem for a cognitive radio in the presence of a smart jammer over parallel Gaussian channels. The objective of the jammer is to minimize the total capacity achievable by the cognitive radio. We model the interaction between the two players as a zero-sum game, for which we derive the saddle point close...

For search and rescue (SAR) missions in emergency and disaster scenarios, unmanned robotic technologies offer an opportunity to save human lives and speed up the rescue process. Communication among the unmanned devices and with the command and control station plays a key role in detecting, locating, and rescuing affected persons. To establish this...

The rapid progress in electronics, sensing, actuation, signal processing, and communication networking has spurred emergence of new technologies like Internet of Things (IoT). In this paper, we report our work on a multi-function IoT (MioT) platform. The MioT supports multiple wireless waveforms that can be used for long as well as short range and...

We model the power allocation interaction between a cognitive radio and a jammer as a two-player zero-sum game. First, we determine the power allocation strategy for the cognitive radio using a modified version of the Q-learning algorithm against fixed jamming strategies. The learned anti-jamming strategy will be compared to the common waterfilling...

Cognitive jammers are able to deploy advanced strategies that degrade the performance of cognitive radio (CR) user communications. In this study, the authors study the problem of power allocation in CR user and jammer games, over parallel Gaussian channels. They model the interaction between a communicator (a transmitter-receiver pair) and a jammer...

This paper describes a low-complexity generic receiver for burst-mode continuous phase modulation. The burst consists of a continuous wave (CW) signal followed by a pseudo-random sequence and a data sequence modulated by continuous phase modulation (CPM). Joint coarse carrier frequency, phase and time synchronization is performed on the CW signal....

Since the jamming attack is one of the most severe threats in cognitive radio networks, we study how Q-learning can be used to pro-actively avoid jammed channels. However, Q-learning needs a long training period to learn the behavior of the jammer. We take advantage of wideband spectrum sensing to speed up the learning process and we make advantage...

Goodness-of-Fit (GoF) testing is a promising approach for blind spectrum sensing in cognitive radio (CR) applications. In this paper, we present a modification on the Anderson-Darling detector by taking into account the physical characteristics of spectrum sensing, resulting in a reduction of the false alarm rate by a factor of two for a given dete...

There is currently no narrowband Combat Net Radio (CNR) STANAG waveform for international and combined missions providing interoperability in Network Centric Operations (NCO). The principal objective of the Narrow Band Waveform (NBWF) is to achieve coalition interoperability within lower tactical levels. Military Software Defined Radio (SDR) equip...

The Cognitive radio technology is a promising solution to the imbalance between scarcity and under utilization of the spectrum. However, this technology is susceptible to both classical and advanced jamming attacks which can prevent it from the efficient exploitation of the free frequency bands. In this paper, we explain how a cognitive radio can e...

The emergence of new wireless services and the growing demand for wireless communications are creating a spectrum shortage problem. Moreover, the current technique of static frequency allocation leads to inefficiency utilization of the available spectrum. Cognitive radio (CR) and dynamic spectrum management (DSM) concepts, aim to solve this imbalan...

The jamming attack is one of the most severe threats in cognitive radio networks, because it can lead to network degradation and even denial of service. However, a cognitive radio can exploit its ability of dynamic spectrum access and its learning capabilities to avoid jammed channels. In this paper, we study how Q-learning can be used to learn the...

High fidelity simulation of cognitive radio networks (CRN) requires a CRN software framework with librairies of components at all layers of the open systems interconnection (OSI) model (e.g. modulation schemes, protocols, routing algorithms) along with realistic channel models for simulating a high number of nodes. At the same time, the CRN softwar...

In this paper, we study a consensus algorithm for distributed spectrum sensing (DSS) in cognitive radio networks (CRN) integrating a Goodness of Fit based spectrum sensing scheme. Existing work in this area often applies energy detector as a local spectrum sensing method for DSS, however in this case one needs to make the assumption that the noise...

Recently, Goodness-of-Fit (GoF) based spectrum sensing has been proposed as a method for blind narrowband spectrum sensing. GoF based spectrum sensing has the nice feature that, compared to Energy Detection, it needs fewer samples to achieve the same sensing performance. In this paper, we present how GoF based spectrum sensing can be integrated in...

In this paper, we study the power allocation problem for a cognitive radio in the presence of a smart jammer over parallel Gaussian channels. The objective of the jammer is to minimize the total capacity achievable by the cognitive radio. We model the interaction between the two players as a zero-sum game, for which we derive the saddle point close...

A robust blind carrier frequency synchronization technique applicable to direct sequence spread spectrum systems is presented. The proposed method extends a blind timing synchronization technique based on the autocorrelation matrix by applying open-loop single frequency estimation algorithms to the eigenvector of the time synchronized autocorrelati...

A blind spectrum sensing method based on the goodness-of-fit (GoF) test using the likelihood ratio is studied. In the proposed method, the χ2 distribution is used for GoF testing. The performance of the method is evaluated through Monte Carlo simulations. It is shown that the proposed spectrum sensing method outperforms the GoF test using Anderson-...

In cognitive radio, spectrum sensing is one of the most important tasks. In this article, a blind spectrum sensing method based on goodness-of-fit (GoF) test using likelihood ratio (LLR) is studied. In the proposed method, a chi-square distribution is used for GoF testing. The performance of the method is evaluated through Monte Carlo simulations....

Today, many software defined radio (SDR) platforms are commercially available as off-the-shelf products at a very reasonable price. The concept of cognitive radio (CR) is to have a network of SDRs which can autoconfigure and autonomously change its parameters (waveform, frequency, bandwidth, power) according to the user needs and the electromagneti...

Cooperative Spectrum Sensing (CSS) has shown to be a powerful solution to improve the sensing performance in cognitive radio (CR) networks. In this paper, we explore the CSS model based on the evolutionary theoretical game to address the interactions between CR users. This paper also provides a detailed overview and analysis on the state of the art...

CogWave is an open-source software framework aiming at developing cognitive radio (CR) waveforms. Multiple waveforms have been implemented in CogWave, such as the multichannel DAA-OFDM waveform, the DADS waveform, and GNU Radio waveforms. CogWave provides the means to implement different CR waveforms and to develop rules to switch between different...

In cognitive radio, spectrum sensing is a challenging task. Proposed is a new spectrum sensing method based on the goodness of fit test of the energy of the received samples with a chi-square distribution. The test statistic is derived and the performance of the proposed method is evaluated by Monte Carlo simulations. It is shown that the proposed...

The TDMA based MAC scheduling is considered appropriate for many applications in which deterministic medium access schedule plays a crucial role. The existing plentiful literature on the TDMA based scheduling focus on the conflict-free slot allocation where the scheduling problem is broken into two disjoint problems: first find conflict free slot a...

To facilitate the introduction of Dynamic Spectrum Access (DSA) technology and associated dynamic spectrum man-agement (DSM) procedures in military tactical radio commu-nication, a roadmap was presented to NATO CaP3 military session in Oct 2012. The main objective of the roadmap was to create a dedicated band for cognitive radio, in the hope that t...

Application of wireless networking technology in tactical and mission-critical environments requires wireless connectivity meets certain quality of service requirements; for example, in such environments timely and reliable delivery of data plays a critical rule in the mission success. For such applications TDMA based MAC scheduling is considered a...

Cognitive Radio is a paradigm for wireless communication in which a wireless node (or a network) can change its transmission and reception parameters according to the user needs and the wireless environment. A cognitive radio transceiver is able to sense, learn, decide and react adaptively to avoid interference with licensed or unlicensed users and...

In this paper, the channel utilization (throughput vs. sensing time relationship) is analyzed for cooperative spectrum sensing under different combining rules and scenarios. The combining rules considered in this study are the OR hard combining rule, the AND hard combining rule, the Equal Gain Soft combining rule and the two-bit quantized (softened...

CogWave is a free and open-source software platform aiming at developing cognitive radio waveforms. Combining CogWave with USRP gives a rapid prototyping platform for physical layer design and algorithm validation through a real-time video, audio and text transmission. This paper presents the cognitive blind orthogonal frequency division multiplexi...

In this paper, a method is proposed to improve the performance of the delay and add direct sequence (DADS) modulation scheme. On one hand, the selection of a short pseudonoise (PN) sequence is used to improve the data rate performance. On the other hand, when high data rates are not required, the same short PN sequence is replicated to form a long...

Application of ad hoc networks in mission-critical environments requires wireless connectivity that meets certain quality-of-service (QoS). In such networks mechanism to control access to the shared wireless channel is crucial to ensure efficient channel utilization and to provide the QoS. TDMA based MAC protocols are considered to be appropriate f...

Cognitive radio is envisioned to solve the problem of spectrum scarcity in military networks and to autonomously adapt to rapidly changing radio environment conditions and user needs. Dynamic spectrum management techniques are needed for the coexistence of multiple cognitive tactical radio networks. Previous work has investigated the iterative wate...

Cognitive radio (CR) technology has to date not been adopted by the military even though more than a decade has passed since its inception. This paper describes how cognitive radio and associated dynamic spectrum management (DSM) procedures can be introduced in military tactical radio communication. CR and DSM address key challenges that face futur...

Cooperative spectrum sensing has proven its efficiency to detect spectrum holes in cognitive radio network (CRN) by combining sensing information of multiple cognitive radio users. In this paper, we study different fusion schemes that can be implemented in fusion center. Simulation comparison between these schemes based on hard, quantized and soft...

In this paper, a method is proposed to improve the noise performance of the delay and add direct sequence (DADS) modulation scheme by modifying the structure of the reference signal and the demodulation algorithm. It is shown that noise reduction by averaging can enhance the bit error rate (BER) performance of DADS considerably. As the number of no...

This paper considers the multiple input multiple output (MIMO) iterative water-filling algorithm (IWFA) for the coexistence of multiple broadcast networks distributing only common information. In the first part of the paper, we propose a power allocation for a MIMO broadcast network using parallel sub-channels and distributing only common informati...

The coherent direct-sequence spread spectrum (DSSS) modulation is a very attractive modulation technique for military communication systems, mainly due to its resistance to interference and low probability of detection (LPD). However, the synchronisation to the spreading code phase in the receiver takes time, which makes this technique less interes...

Cognitive Radio is a paradigm for wireless communication in which a wireless node (or a network) can change its transmission and reception parameters according to the user needs and the wireless environment. A cognitive radio transceiver is able to sense, learn, decide and react adaptively to avoid interference with licensed or unlicensed users and...

The growth in wireless technology and the increasing demand for wireless multimedia services creates a lack of spectrum. A potential solution to this issue is to allocate the spectrum dynamically by means of cognitive radio. Iterative Water Filling (IWF) can offer a practical solution to this dynamic spectrum allocation. Straightforward implementat...

Wire-tap channels are able to provide perfect secrecy when a receiver exhibits a better channel than its wire-tapping opponent. In this letter, we extend the perfect secrecy principle to parallel Gaussian multiple input multiple output (MIMO) wire-tap channels with independent sub-channels. Assuming N_r ≥ N_t and N_e ≥...

Recently, correlation delay shift keying (CDSK) has been proposed as a modulation scheme for noncoherent detection which inherits the advantages of conventional spread-spectrum communications using a chaotic reference signal. The CDSK modulation scheme transmits the sum of a chaotic reference signal with its delayed modulated version. In this paper...

In this paper, dynamic spectrum management is studied for multiple cognitive tactical radio networks coexisting in the same area. A tactical radio network is composed of a transmitter which broadcasts the same information to its multiple receivers. First, we consider the problem of power minimization subject to a minimum rate constraint and a spect...

In this paper a novel analytical model for the saturation throughput of unslotted Carrier Sensing Multiple Access with Collision Avoidance (CSMA/CA) in wireless networks is proposed. A fixed point procedure is developed based on the interaction of the Physical layer (PHY) and the Medium Access Control sub-layer (MAC). The output of the Clear Channe...

In this paper, we consider the scenario in which N different cognitive radio networks can not cooperate with each other and wish to broadcast a common information to their network by sharing the same Nc parallel sub-channels. This scenario is particularly adapted to tactical radio networks in which N different networks coexist in a given area and b...

The Direct-Sequence Spread Spectrum modulation (DSSS) is a very attractive modulation technique for military communication systems, mainly due to its resistance to interference and low probability of de-tection. However, the synchronisation to the spreading code phase in the receiver takes time, which makes this technique less interesting for sendi...

This paper deals with an extension to the hybrid simulation paradigm, i.e. the combination of event-driven simulation and analytical modelling, applied to packet telecommunica-tion networks. In order to speed up the simulation only a small part of all packets, the foreground traffic, is processed in an event-driven way. On each arrival of a foregro...

A tactical radio network is a radio network in which a transmitter broadcasts the same information to its receivers. In this paper, dynamic spectrum management is studied for multiple cognitive tactical radio networks coexisting in the same area. First, we consider the problem of common rate maximization subject to a total power constraint for a si...

Cognitive Radio is a paradigm for wireless communication in which a wireless node (or a network) can change its transmission and reception parameters according to the user needs and the wireless environment. A cognitive radio transceiver is able to sense, learn, decide and react adaptively to avoid interference with licensed or unlicensed users and...

Cognitive Radio is one of the most promising para-digms for wireless communication, as it enables a flexible use of the radio spectrum. For this, several new techniques were developed that provide a good overview about the current spectrum usage and fa-cilitate dynamic adaptation to it. Moreover, it was investigated how to integrate those technique...

In this paper, the ongoing research at the Belgian Royal Military Academy on the performance analysis of wireless networks is presented. A validation by measurements on a testbed is proposed for the MAC event-driven simulator [4] developed at the Royal Military Academy. In a first part, the simulator is introduced and the non beacon-enabled access...

In this paper an accurate model for the evaluation of the throughput in a CSMA/CA multi-hop wireless network with arbitrary topology is proposed. A fixed-point procedure is developed based on an extended analysis of the air-time of a link and on a decoupling procedure to estimate the air-time of a node. The intrinsic fairness of a MAC protocol e.g....

In this paper a semi-analytical model for the evaluation of the queuing performance in CSMA-CA multi-hop wireless networks with arbitrary topology is proposed. The intrinsic fairness of single-hop wireless networks can be used to model the network as a processor sharing system with multiple queues, one for each node, and a fair scheduling regime. I...

In this paper, the queuing performance of multi-hop CSMA/CA networks and in particular IEEE802.11 RTS/CTS access is evaluated. The intrinsic fairness of a single-hop wireless network can be used to model the network as a processor sharing system with multiple queues and a fair scheduling regime. In a multi-hop scenario, the lack of coordination can...

Ad hoc networks are considered to be a very promising technology. Despite the importance and the variety of possible applications, they still suffer from some basic problems. One of the most important issues of wireless sensor networks is their restricted amount of energy resources, and therefore their restricted autonomy. This paper tries to reduc...

In this paper, numerical calculation schemes of the buffer occupation probability for a buffer which is fed by a large number of independent and stationary sources are evaluated. The resulting buffer occupation probability density function can be sampled in order to model the impact of a background traffic stream on the foreground traffic in a hybr...

This paper introduces a novel hybrid packet-event / fluid-flow network simulation scheme. A packet-event simulation technique uses the arrivals and the departures of packets to model the queuing system. The applications that need fine-grained performance details, are simulated with an adapted event based approach. The impact of the background traff...

In this paper a summary is given of the ongoing research at the Belgian Royal Military Academy in the field of Mobile Ad Hoc Networks in general and Wireless Sensor Networks (WSN) in particular. In this study, all Wireless Sensor Networks are based on the physical and the medium access layer of the IEEE802.15.4 Low Rate Wireless Personal Area Netwo...

The information transfer across the battlespace is expanding at an ever increasing pace. Simulations have to be carried out to ensure the quality of service of the different applications (sensors, command and control systems, voice communications, . . .) all integrated in a dynamic network environment. Two approaches are common: discrete event simu...

Migration is a common name for processing techniques that try to reconstruct, from the dat recorded at the surface, the reflecting structures in the sub-surface. Most of the existing migration techniques do not take into account the characteristics of the acquisition system and the ground characteristics. We propose a novel migration method, applic...

A common way of describing antennas in the time domain is by means of their impulse response. When the time-domain antenna equations are expressed in terms of the normalised impulse response (normalised IR), they become very simple to use, because all frequency-dependent antenna characteristics are included in the normalised IR. This paper describe...

In this paper, the time domain modelling of an indoor impulse UWB GPR systems (1GHz-5GHz), built in the scope of the HUDEM project, is presented. For an impulse UWB system, a time-domain modelling is an obvious choice. We explain how the antennas can be characterised by their normalised impulse response. By considering the antenna as a convolution...

In this paper, the design and the modelling of an indoor impulse UWB GPR systems (1GHz-5GHz), built in the scope of the HUDEM project, is presented. For an impulse UWB system, a time-domain modelling is an obvious choice. We explain how the antennas can be characterised by their normalised impulse response. By considering the antenna as a convoluti...