Emanuel Radoi

Emanuel Radoi
Université de Bretagne Occidentale | UBO · Laboratoire des sciences et techniques de l’information, de la communication et de la connaissance- LABSTICC (UMR 3192)

PhD

About

107
Publications
13,857
Reads
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639
Citations
Citations since 2016
20 Research Items
340 Citations
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
Additional affiliations
September 1992 - November 2002
Technical Military Academy of Bucharest
Position
  • Professor (Assistant)

Publications

Publications (107)
Conference Paper
People counting using an IR-UWB radar, based on Artificial Intelligence classification algorithms, is investigated in this paper. Ultra-wideband (UWB) impulses have a duration of nanoseconds in the time domain, occupying a very large frequency bandwidth, from 500 MHz up to 7.5 GHz [1]. UWB technology is used for surveillance, detection, positioning...
Article
This article aims to propose new techniques to detect and distinguish humans from moving machines in indoor environments. Although many research efforts have been already dedicated to humans’ indoor detection, most of the work has been focused on counting people and crowd measurement for consumer business applications. Our objective is to develop a...
Article
Transform-based block digital filtering (BDF) is a powerful tool for reducing computational complexity and increasing the parallelism of digital filtering systems. Most commonly used transforms, such as the discrete Fourier transform (DFT) and the discrete cosine transform (DCT), are not suitable for fixed-point implementation since they lead to a...
Article
Full-text available
In the last years, the commercial drone/unmanned aerial vehicles market has grown due to their technological performances (provided by the multiple onboard available sensors), low price, and ease of use. Being very attractive for an increasing number of applications, their presence represents a major issue for public or classified areas with a spec...
Article
Full-text available
The commercial drone market has substantially grown over the past few years. While providing numerous advantages in various fields and applications, drones also provide ample opportunities for misuse by irresponsible hobbyists or malevolent actors. The increasing number of safety/security incidents in which drones are involved has motivated researc...
Conference Paper
Full-text available
This paper deals with the influence of a wideband signal key parameters on its spectrum reconstruction, for Internet-of-Things (IoT) applications. The impact of the frequency resolution , the bandwidths of the sensed transmitters, and the frequency spacing between their subbands are thoroughly analyzed. The spectrum detection of LoRaWAN EU868, one...
Article
This paper focuses on non-ideal filters in a Modulated Wideband Converter (MWC) scheme. The MWC is a system that can sample a sparse wideband signal at sub-Nyquist rate. Generally, the output of the ideal MWC components will ensure a perfect reconstruction. In practice, the reconstruction should be based on the output of non-ideal components, espec...
Article
In this paper, we focus on the optimization of a linear multiple-input multiple-output (MIMO) precoder assuming an outer forward error correction code and an iterative minimum mean square error (MMSE)-based interference cancellation (turbo equalization) at the receiver side. Given perfect channel state information at both sides of the communication...
Article
A precoding design is proposed for Multiple-Input Multiple Output (MIMO) systems utilizing non-binary low density parity check (NB-LDPC) codes and many-to-one mapping. When a high-order modulation scheme is used, many-to-one mapping converts a group of low-order Galois Field (GF) coded symbols into one modulated MIMO symbol vector. In contrast, one...
Article
Precoder optimization with full channel state information (CSI) for finite alphabet signals over multiple-input multiple-output (MIMO) random channels is investigated in this paper. The precoder is represented by a product of power allocation matrix and constellation-forming matrix. There was an optimal algorithm introduced in literature to globall...
Article
In this paper, we propose a compressed sensingbased approach for channel estimation in wireless ultra-wideband (UWB) communication systems. The channel is estimated from a minimum number of received signal Fourier coefficients, using a measurement matrix dependent on the transmitted waveform. The optimal subset of coefficient locations, which lower...
Conference Paper
The concatenation of multiple-input multiple-output (MIMO) linear precoder with an outer forward error correction (FEC) encoder is investigated at the transmitter. Turbo detection is applied at the receiver for the decoding. The bit-interleaved codeword is considered to be grouped and mapped directly onto the received constellation thanks to a MIMO...
Conference Paper
In this paper, we propose a low complexity multichannel scheme for Ultra Wideband (UWB) channel impulse response estimation. It is mainly based on the finite rate of innovation (FRI) characteristic of UWB channel impulse response, which allows for a sampling frequency much lower than the Nyquist limit. Since the UWB channel is rich in multipaths, t...
Article
The finite rate of innovation is a recently proposed concept for reducing the sampling frequency of signals depending on a finite number of parameters. In this paper, low complexity sampling schemes are designed for bandpass signals, which are typical for ultra-wideband (UWB) transmissions. Firstly, two compressed sensing schemes, single-channel (S...
Conference Paper
In this paper, we investigate the concatenation of the multiple input multiple output (MIMO) maxdmin linear precoder with an outer forward error correction (FEC) code at the transmitter. At the receiver side, the turbo equalization is taken into account, which iteratively exchanges the textit{extrinsic} information between a minimum mean square err...
Article
Full-text available
In cognitive radio context, the parameters of coding schemes are unknown at the receiver. The design of an intelligent receiver is then essential to blindly identify these parameters from the received data. The blind identification of code word length has already been extensively studied in the case of binary error-correcting codes. Here, we are in...
Conference Paper
In this paper we investigate the concatenation of the multiple input multiple output (MIMO) max-dmin linear precoder with an outer forward error correction (FEC) code assuming turbo detection at the receiver. A maximum squared Euclidean weight (MSEW) binary-to-MIMO symbol mapper is introduced in the precoding scheme. Extrinsic information transfer...
Article
Full-text available
In multiple-input multiple-output (MIMO) transmission systems, the channel state information (CSI) at the transmitter can be used to add linear precoding to the transmitted signals in order to improve the performance and the reliability of the transmission system. This paper investigates how to properly join precoded closed-loop MIMO systems and no...
Conference Paper
The new theory addressed to signals with finite rate of innovation (FRI) is based on the concept of minimal sampling rate of a stream of pulses. This paper describes the feasibility of two minimal sampling rate techniques not only in the case of Gaussian UWB pulse but also for its derivatives. Since the derivatives of Gaussian pulses are represente...
Article
A novel decoding algorithm for non-binary low density parity check (NB-LDPC) codes is proposed. The algorithm builds on the recently designed parallel symbol-flipping decoding (PSFD) algorithm and combines a technique of error estimation and a method of multiple voting levels from each unsatisfied check-sum to the corresponding variable nodes. Simu...
Article
Full-text available
In this paper, we develop a statistical characterization of the multipath interference in an Impulse Radio (IR)-UWB system, considering the standardized IEEE 802.15.4a channel model. In such systems, the chip length has to be carefully tuned as all the propagation paths located beyond this limit can cause interframe/intersymbol interferences (IFI/I...
Article
Cognitive radio (CR) was proposed as a solution to the spectrum scarcity problem. One of the basic functions of any CR is spectrum sensing. Most existing works on spectrum sensing consider the Gaussian noise assumption. In practice, this assumption is not always valid since several existing noise types exhibit non-Gaussian and impulsive behavior. H...
Conference Paper
This paper investigates the feasibility of three image reconstruction algorithms for Ultra Wideband (UWB) signals in applications of detection and localization of human targets behind obstructing surfaces. The image reconstruction algorithms are represented by unfocused SAR (Synthetic Aperture Radar), focused SAR and Radon transform based tomograph...
Conference Paper
The integration of all the heterogeneous wireless networks deployed along European railway lines constitutes a key technical challenge to improve global efficiency of railway system. Emerging Cognitive Radio (CR) technologies can answer this challenge. The paper presents the first results obtained in the ANR project CORRIDOR (Cognitive Radio for Hi...
Article
Full-text available
Two challenges for rescue robots are to detect human beings and to have an accurate positioning system. In indoor positioning, GPS receivers cannot be used due to the reflections or attenuation caused by obstacles. To detect human beings, sensors such as thermal camera, ultrasonic and microphone can be embedded on the rescue robot. The drawback of...
Article
Full-text available
Timing synchronization is a major issue for any communication system since it is essential to ensure its stable operation and reliable performance. In this paper, we compare two low-complexity synchronization algorithms for impulse radio ultra-wideband (IR-UWB) system, employing orthogonal pulse shape modulation (PSM). The two widely adopted modula...
Conference Paper
In this paper, we present a transmission model for a multiple-input multiple-output (MIMO) channel with perfect channel state information (CSI). We intend to exploit the available CSI through the use of a precoder based on the minimum Euclidean distance (dmin) criterion. We also introduce a low density parity check coding block in order to improve...
Article
Full-text available
In this paper, we suggest to use low cost robots and Ultrawideband (UWB) technology in order to help elderly. In the context of the targeted application, a mobile robot is designed to remotely interact with a person acting as supervisor, and also to monitor their environment. UWB is then very helpful to ensure precise localization of the robot insi...
Article
Timing synchronization is a critical as well a challenging issue in ultra-wideband impulse radio (UWB-IR) due to their particular transmission characteristics. This letter proposes a rapid synchronization algorithm which can achieve frame-level synchronization in non-data-aided (NDA) mode. Relying on a unique transmit signal pattern based on orthog...
Conference Paper
Full-text available
This paper deals with timing recovery for Impulse Radio (IR) ultra-wideband (UWB) communication systems, which is known to be a challenging task to accomplish. We focus on blind estimation approaches, with the aim of being able to operate with minimal constraints on the signal format (no use of pilot symbols). We consider also the blind timing esti...
Conference Paper
In the cognitive radio field, the receiver should be able to perform a blind identification of the encoder parameters used by the transmitter from the only knowledge of the received data stream. In this context, the most methods dedicated to the blind identification of the parameters of error correcting codes are based on the rank calculation of ma...
Conference Paper
Full-text available
In this paper, we consider the problem of sensing a primary user in a cognitive radio network by employing multiple-antennas at the secondary user. Among the many spectrum sensing methods, the predicted eigenvalue threshold (PET) based method is a promising non-parametric blind method that can reliably detect the primary users without any prior inf...
Conference Paper
In this paper, we consider the problem of sensing a primary user in a cognitive radio network by employing multiple-antennas at the secondary user. Among the many spectrum sensing methods, the predicted eigenvalue threshold (PET) based method is a promising non-parametric blind method that can reliably detect the primary users without any prior inf...
Article
Full-text available
Ultra wideband (UWB) radio has emerged as an attractive candidate for short-range wireless communications in recent years due to its unique features. However, implementation of UWB radios in order to utilize these features is coupled with some pronounced design challenges. To achieve precise timing synchronization is one of the most crucial task am...
Article
Ultra wideband (UWB) radio has emerged as an attractive candidate for short-range wireless communications in recent years due to its unique features. However, implementation of UWB radios in order to utilize these features is coupled with some pronounced design challenges. To achieve precise timing synchronization is one of the most crucial task am...
Conference Paper
Full-text available
Synchronization is a key performance-limiting factor in any communication system and a challenging task to accomplish. In this paper, an energy detection based non data-aided (NDA) algorithm for orthogonal pulse shape modulated (PSM) impulse radio ultra wideband (IR-UWB) system is proposed. Relying on unique signal structure, simple overlap-add ope...
Conference Paper
The blind interception process of multiple-input multiple-output (MIMO) signals have recently gained more attention. The number of transmitting antennas is an important information for many blind MIMO algorithms. In this paper, several algorithms for blind detection of the number of transmitting antennas are presented. These different algorithms ar...
Article
Full-text available
In this paper, an optimal approach based on B-splines functions is presented for the design of ultra wideband (UWB) pulses which satisfy simultaneously the following 3 criteria : compatibility with the spectral mask authorised in USA or in Europe, spectral efficiency and orthogonality of generated pulses. The first property allows UWB systems to co...
Article
Full-text available
Indoor propagation channel appears differently to ultra-wideband (UWB) systems than it does to narrowband systems. UWB signals have very high temporal resolution ability and this implies a frequency-selective channel with rich multipath in practice. To capture the signal energy spread over a multipath environment, a Rake receiver consisting of mult...
Article
Overlap-save (OLS) and overlap-add (OLA) are two techniques widely used in digital filtering. In traditional OLS and OLA implementations, the system is compelled to be time-invariant and conventional filter synthesis techniques are used for designing the block filter. In this paper, based on the OLS and the OLA structures, we develop a fast algorit...
Article
Scattering centers model (SCM) is usually considered for modeling target backscattered signal in high-resolution radar. In this case the impulse response of each scattering center is represented by a time-delayed Dirac pulse. Some of most popular superresolution imagery techniques, such as MUSIC or ESPRIT, are well-matched to this model. Under this...
Article
Full-text available
Robust naval target detection is of significant importance to national security, to navigation safety, and to environmental monitoring. Here we consider the particular case of high resolution coastal radars, working at low grazing angles. The robustness of detection heavily relies on the appropriate knowledge of two classes of backscattered signals...
Book
This book uses MATLAB as a computing tool to explore traditional DSP topics and solve problems. This greatly expands the range and complexity of problems that students can effectively study in signal processing courses. A large number of worked examples, computer simulations and applications are provided, along with theoretical aspects that are ess...
Book
Cet ouvrage présente de manière claire et concise les principales techniques de traitement du signal et les résultats les plus fondamentaux sous une forme directement exploitable par une évaluation rapide d'exercices et de problèmes en utilisant l'outil de simulation Matlab. Le traitement du signal sous Matlab permet de mieux appréhender les diffic...
Article
The paper describes a simulation methodology for radar targets in marine environment. Our approach is based on a new model, called "Scattering Center Set Unified Representation", which is able to approximate the backscattered radar target echo for any aspect angle. This model is fast to calculate and has the advantage to take into account the parti...
Article
The paper describes a simulation methodology for radar targets in marine environment. Our approach is based on a new model, called "Scattering Center Set Unified Representation", which is able to approximate the backscattered radar target echo for any aspect angle. This model is fast to calculate and has the advantage to take into account the parti...
Article
This paper deals with the optimal detection of man-made targets in UWB SAR images obtained using a FOPEN radar. Conventional detection algorithms perform poorly in this case, mainly because of the spiky aspect of the foliage clutter. We propose to use the K-compound distribution to model this kind of impulsive clutter. A method to overcome the prob...
Article
Full-text available
The problem of the automatic classification of superresolution ISAR images is addressed in the paper. We describe an ane- choic chamber experiment involving ten-scale-reduced aircraft models. The radar images of these targets are reconstructed using MUSIC-2D (multiple signal classification) method coupled with two additional processing steps: phase...
Article
Full-text available
The paper presents an evolutionary approach for 3D superresolution (SR) imagery combining the CLEAN method and an optimization procedure based on genetic algorithms (GA). Actually, this is an extension of some previously published research works on evolutionary programming (EP) based CLEAN method in 1D and 2D cases. Measured data results obtained u...
Conference Paper
The retrieval of soccer highlights is a suitable technique for video indexing, required by the multimedia database management or for the development of television on demand. For these purposes, it should be interesting to have an automatic annotation of events happened in soccer games. One solution consists in analyzing the audio soundtrack associa...
Conference Paper
Full-text available
Our research work has been focused for several years on ISAR techniques and ATR using superresolution radar imagery. The anechoic chamber of ENSIETA at Brest and the associated measurement facilities allow us to obtain radar signatures for various scale reduced targets and to reconstruct their radar images using a turntable configuration. The paper...
Conference Paper
Full-text available
The main purpose of the paper is to propose a framework for validating radar target models using superresolution imagery methods. The need for realistic target models becomes more and more imperative as the radar technological capabilities and the signal processing techniques are continually improved. Simple scattering configurations, such as a set...