- Advanced Wireless Communication Techniques
- Wireless Communication Networks Research
- Cooperative Communication and Network Coding
- Advanced MIMO Systems Optimization
- Error Correcting Code Techniques
- Advanced Wireless Communication Technologies
- Advanced Wireless Network Optimization
- PAPR reduction in OFDM
- Satellite Communication Systems
- Power Line Communications and Noise
- Full-Duplex Wireless Communications
- Remote Sensing and LiDAR Applications
- Wireless Communication Security Techniques
- Energy Harvesting in Wireless Networks
- Remote-Sensing Image Classification
- 3D Surveying and Cultural Heritage
- Coding theory and cryptography
- Advanced Image and Video Retrieval Techniques
- Millimeter-Wave Propagation and Modeling
- Automated Road and Building Extraction
- Image Retrieval and Classification Techniques
- Optical Network Technologies
- Advanced Data Compression Techniques
- Blind Source Separation Techniques
- Vehicular Ad Hoc Networks (VANETs)
National and Kapodistrian University of Athens
2016-2025
Beijing University of Posts and Telecommunications
2017
National Observatory of Athens
2006-2015
Netherlands Institute for Radio Astronomy
2013-2014
Institute of Informatics & Telecommunications
2010
National Centre of Scientific Research "Demokritos"
2010
Southwest Jiaotong University
2009
University of Surrey
2007
Center For Remote Sensing (United States)
2006
Aristotle University of Thessaloniki
2006
For more than a decade now, radio frequency identification (RFID) technology has been quite effective in providing anti-counterfeits measures the supply chain. However, genuineness of RFID tags cannot be guaranteed post chain, since these can rather easily cloned public space. In this paper, we propose novel product ownership management system (POMS) RFID-attached products for that used purpose, leverage idea Bitcoin's blockchain anyone check proof possession balance. With proposed POMS,...
The performance of digital communication systems over generalized-K (K/sub G/) fading channels is analyzed and evaluated. Novel closed form expressions for the SNR statistics, average Shannon's channel capacity bit error rate (BER) are derived. These used to study important criteria such as outage performance, BER a great variety modulation formats in K/sub G/ channels. proposed mathematical analysis accompanied with various evaluation results, which demonstrate usefulness approach.
A generic and novel distribution, referred to as Nakagami, constructed the product of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> statistically independent, but not necessarily identically distributed, Nakagami- xmlns:xlink="http://www.w3.org/1999/xlink">m</i> random variables (RVs), is introduced analyzed. The proposed distribution turns out be a very convenient tool for modelling cascaded fading channels analyzing performance digital...
The performance of full-duplex (FD) cooperative non-orthogonal multiple access (C-NOMA) relaying systems in the presence in-phase and quadrature-phase imbalance (IQI) imperfect successive interference cancellation (ipSIC) is analyzed evaluated. In particular, by considering two classes users located far from near to information source, closed-form exact analytical approximate expressions for outage probability (OP) ergodic sum rate (ESR), respectively, are derived. accuracy approach verified...
The end-to-end performance of dual-hop cooperative diversity systems equipped with nonregenerative relays and a selection combining receiver at the destination terminal over independent nonidentical Nakagami- fading channels is studied. Closed-form expressions for cumulative distribution function probability density signal-to-noise ratio ( ) are presented, while analytical formulae derived moments moment generating function. Using these statistical results, closed-form outage presented both...
The effective extraction of shape features is an important requirement for the accurate and efficient classification terrestrial laser scanning (TLS) point clouds. However, challenge how to obtain robust discriminative from noisy varying density TLS clouds remains. This paper introduces a novel multiscale hierarchical framework, which describes cluttered urban scenes. In this we propose clusters (MHPCs). MHPCs, are first resampled into different scales. Then, data set each scale aggregated...
In this paper, a methodology which allows automated and efficient reconstruction of three-dimensional (3-D) geometric building models from an Airborne Laser Scanning (ALS) point cloud is introduced its performance analyzed evaluated. The proposed method avoids abnormal and/or infinite solutions are typically encountered in previously published methods that use the rooftop primitive adjacency matrix to solve critical vertices. particular, first, improved random sample consensus (RANSAC)...
Massive connectivity and low latency are two important challenges for the Internet of Things (IoT) to achieve quality service provisions required by numerous devices it is designed service. Motivated these challenges, in this paper we introduce a new millimeter-wave nonorthogonal multiple access (mmWave-NOMA) transmission scheme cellular machine-to-machine (M2M) communication systems IoT applications. It consists one base station (BS) machine type (MTC) operating environment. We consider its...
In this paper, a novel three-dimensional (3-D) indoor positioning scheme is proposed for millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) systems. Its operation based upon hybrid received signal strength and angle of arrival (RSS-AoA) scheme, which employs only single access point equipped with large-scale uniform cylindrical array. To reduce the high computational complexity imposed by large number antennas used in mmWave MIMO (M <sup...
Point cloud classification plays a critical role in point processing and analysis. Accurately classifying objects on the ground urban environments from airborne laser scanning (ALS) clouds is challenge because of their large variety, complex geometries, visual appearances. In this paper, novel framework presented for effectively extracting shape features an ALS cloud, then, it used to classify small cloud. framework, split into hierarchical clusters different sizes based natural exponential...
With the emergence of huge volumes high-resolution remote sensing images produced by all sorts satellites and airborne sensors, processing analysis these require effective retrieval techniques. To alleviate dramatic variation accuracy among queries caused single image feature algorithms, we developed a novel graph-based learning method for effectively retrieving images. The utilizes three-layer framework that integrates strengths query expansion fusion holistic local features. In first...
Accurate identification and segmentation of individual tree points are crucial for assessing forest spatial distribution, understanding growth structure, managing resources. Traditional methods based on Canopy Height Models (CHM) simple yet prone to over- and/or under-segmentation. To deal with this problem, paper introduces a novel approach that combines marker-controlled watershed spectral clustering algorithm. Initially, we determined the local maxima within series variable windows...
A detailed performance analysis for the most important diversity receivers operating over a composite fading channel modeled by generalized-K (Kg) distribution is presented. The Kg has been recently considered as generic and versatile accurate modeling of great variety short term in conjunction with long (shadowing) conditions. For this relatively new model, expressions statistical metrics maximal ratio combining (MRC), equal gain (EGC), selection (SC) switch stay (SSC) are derived. Using...
SUMMARY This paper presents a feasibility study for fixed broadband access High Throughput Satellite terabit/second system by considering appropriate state‐of‐the‐art communication technologies. For the investigated model, DVB‐S2 and DVB‐RCS2 are assumed as air interfaces forward return link, respectively. The performance of Adaptive Coding Modulation is examined along with potential extensions these standards. example, very low rate DVB‐RCS turbo codes their evaluated. In addition,...
Bitcoin is one of the most popular decentralized cryptocurrencies to date. However, it has been widely reported that can be used for investment scams, which are referred as high yield programs (HYIP). Although from security forensic point view very important identify HYIP operators' addresses, so far in open technical literature no systematic method reliably collects and identifies such addresses proposed. In this paper, a novel methodology introduced, efficiently large number them based...
The use of optical spatial modulation (OSM) is proposed as a simple low-complexity means achieving diversity in coherent free-space (FSO) communication systems. In doing so, this paper presents generic analytical framework for obtaining the average bit error probability (ABEP) uncoded and coded OSM with detection presence turbulence-induced fading. Although general enough to accommodate any type channel models based on turbulence scattering, focus analysis H-K distribution such model very...
Although Bitcoin is one of the most successful decentralized cryptocurrency, recent research has revealed that it can be used as fraudulent activities such HYIP (High Yield Investment Program). To identify undesired activities, important to obtain addresses related with fraud. So far, identification based upon relating graph mining procedures. In this paper, we follow a different approach for identifying by analyzing transactions patterns. particular, on individual inspection activity in...
Ascertaining the importance of dual selection combining (SC) receivers and suitability Weibull model to describe mobile fading channels, we study performance a SC receiver over correlated channels with arbitrary parameters. Exact closed-form expressions are derived for probability density function, cumulative distribution moments output signal-to-noise ratio (SNR). Important criteria, such as average SNR, amount fading, outage probability, bit-error several modulation schemes studied....
The level crossing rates (LCRs) and average fade durations (AFDs) of a fading channel find diverse applications in the evaluation design wireless communication systems. Analytical expressions for these quantities are available literature certain diversity reception techniques, but generally limited to Rayleigh channel, with few exceptions. Moreover, methods employed usually specific channel/diversity pair, thus cannot be applied all cases interest. Using unified methodology, we derive...
The maximum likelihood sequence estimator for the reception of coded digital phase modulated signals with single or multiamplitude constellations, transmitted over a multiplicative, frequency-nonselective (i.e., flat) correlated fast fading Rayleigh Rician channel and corrupted by additive white Gaussian noise (AWGN), is derived. Due to this correlation, errors caused tend occur in bursts. In analysis, no assumption simplifying problem made. For authors consider most general case where both...
This paper investigates the end-to-end performance of a dual-hop amplify-and-forward (AF) relaying communication system where source-to-relay and relay-to-destination channels are subject to different fading conditions. The relay is assumed either possess perfect channel state information (CSI) or have fixed gain. We consider case one hop's <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex...
A 3-D tree structure plays an important role in many scientific fields, including forestry and agriculture. For example, terrestrial laser scanning (TLS) can efficiently capture high-precision spatial arrangements of trees as a point cloud. In the past, several methods to reconstruct from TLS cloud were proposed. However, general, they fail process incomplete data. To address such data sets, new method that is based on structure-aware global optimization approach (SAGO) The SAGO first...
The ability to classify urban objects in large scenes from point clouds efficiently and accurately still remains a challenging task today. A new methodology for the effective accurate classification of terrestrial laser scanning (TLS) is presented this paper. First, order obtain complementary characteristics each 3-D point, set point-based descriptors recognizing constructed. This includes geometry captured using spin-image descriptor computed on three different scales, mean RGB colors...