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January 1999 - December 2012
January 1998 - present
Publications
Publications (311)
This chapter introduces wireless communications systems and explains the different products and standards related to wireless communications. The chapter is divided into five main sections.
A brief introduction offers a perspective on the evolution of wireless communications systems and introduces a useful classification. After this introduction, a...
The Internet of Vehicles (IoV) is an evolution of the Internet of Things (IoT). IoV allows real-time information-sharing of intra-vehicle, inter-vehicle and vehicle to the roadside base stations, which improves transport safety and reduces road traffic accidents. Due to the increased number of vehicles in IoV networks, the allocated spectrum bands...
This chapter introduces wireless communications systems and explains the different products and standards related to wireless communications. The chapter is divided into five main sections.
A brief introduction offers a perspective on the evolution of wireless communications systems and introduces a useful classification. After this introduction, a...
In this paper, to tackle the blockage issue in massive multiple-input-multiple-output (mMIMO) systems, a reconfigurable intelligent surface (RIS) is seamlessly deployed to support devices with ultra-reliable and low-latency communications (URLLC). The transmission power of the base station and the phase shifts of the RIS are jointly devised to maxi...
Visible light communication (VLC) complements radio frequency in indoor environments with large wireless data traffic. However, VLC is hindered by dramatic path losses when an opaque object is interposed between the transmitter and the receiver. Prior works propose the use of plane mirrors as optical reconfigurable intelligent surfaces (ORISs) to e...
This article continues the series of ten interviews with the Officers of the IEEE ComSoc Member and Global Activities (MGA) Council for the term 2024-2025, which will be published every month in the Global Communications Newsletter.
This article opens the series of ten interviews with the Officers of the IEEE ComSoc Member and Global Activities (MGA) Council for the term 2024–2025, which will be published every month in the Global Communications Newsletter.
Sixth-generation (6G) networks are poised to revolutionize communication by exploring alternative spectrum options, aiming to capitalize on strengths while mitigating limitations in current fifth-generation (5G) spectrum. This paper explores the potential opportunities and emerging trends for cmWave and sub-THz spectra as key radio enablers. This p...
Presents information and current topics of interest to the global communications industry.
The rise in popularity and the increasing number of Internet of Things (IoT) devices have raised significant challenges, such as heterogeneity, application needs, limited resources, and connectivity. Among these challenges, ensuring optimal connectivity for IoT devices stands out as a critical aspect. Integrating satellite-based networks into tradi...
It is a great privilege and honor for me to serve as President of the IEEE Communication Society (ComSoc) for the years of 2024 and 2025. The tireless efforts of our past presidents, volunteer leaders, members, and supporting staff have made ComSoc the leading global organization for communications and networking professionals. I would particularly...
Under high-mobility scenarios, the traditional coherent demodulation schemes (CDS) have limited performance, because reference signals cannot effectively track the channel variations with an affordable overhead. As an alternative solution, non-coherent demodulation schemes (NCDS) based on differential modulation have been proposed. Even in the abse...
The Third IEEE International Mediterranean Conference on Communications and Networking (IEEE MEDITCOM 2023) took place in September 2023 in Dubrovnik, Croatia. This article explains the main highlights of the four-day Technical Program of the conference that took place on the shore of the Mediter-ranean, addressing many of the outstanding challenge...
It has been a great honor and privilege for me to serve as the President of IEEE Communications Society (ComSoc) in 2022–2023. The IEEE ComSoc is a global professional organization that has been creating cutting-edge communications and networking technologies through its high-quality publications, premier conferences, technology standards, educatio...
Superimposed Training (ST) is one of the most appealing channel estimation techniques for Orthogonal Frequency Division Multiplexing (OFDM), to be possibly exploited in 6G. The data and pilot symbols are sharing the same time and frequency resources, and hence, the overhead is significantly reduced. Moreover, the superimposed pilots can be also use...
This article continues the series of interviews to the Officers of the IEEE ComSoc Member and Global Activities (MGA) Council, which is published every month on the Global Communications Newsletter.
Novel and cutting-edge use cases have arisen since the first deployments of the fifth generation (5G) of mobile communications. We can already find multiple 5G simulators and emulators in the state-of-the-art which allow engineers and researchers to thoroughly study and test the network. However, the 5G ecosystem is not only limited to the network...
Existing mobile communication systems are unable to support ultra high system capacity and high reliability for the edge users of future 6G systems, which are envisioned to guarantee the desired quality of experience. Recently, cell-less radio access networks (RAN) are exploited to boost the system capacity. Therefore, in this letter we propose a c...
4×4 Multiple Input Multiple Output (MIMO) optical architecture based on Radio over Fiber (RoF) is proposed for 5G millimeter Wave (mmWave) indoor applications in the unlicensed 60 GHz band. First-order and second-order sidebands, generated by Dual-Drive Mach-Zehnder Modulator (DD-MZM), are exploited as optical subcarriers in order to reduce the num...
Vehicle-to-vehicle (V2V) communications are one of the most promising 6G scenarios. However, V2V communications demand high data rates and extremely low-latency requirements that are difficult to satisfy nowadays. Recently, vehicular visible light communications (V-VLC) have been proposed as a promising technology to guarantee such requirements. Mu...
In recent years, advances in immersive multimedia technologies, such as extended reality (XR) technologies, have led to more realistic and user-friendly devices. However, these devices are often bulky and uncomfortable, still requiring tether connectivity for demanding applications. The deployment of the fifth generation of telecommunications techn...
In this chapter, the use of massive open online courses (MOOCs) for the dissemination, training capabilities and learning of telecommunication engineering is described taking as example the successful MOOC 'Ultra-Dense Networks for 5G and its Evolution' developed under the European innovative training network (ITN) TeamUp5G. MOOCs are usually under...
In this chapter, the use of massive open online courses (MOOCs) for the dissemination, training capabilities and learning of telecommunication engineering is described taking as example the successful MOOC ``Ultra-Dense Networks for 5G and its Evolution'' developed under the European innovative training network (ITN) TeamUp5G. MOOCs are usually und...
We address the latency challenges in a high-density and high-load scenario for an ultra-reliable and low-latency communication (URLLC) network which may coexist with enhanced mobile broadband (eMBB) services in the evolving wireless communication networks. We propose a new radio resource management (RRM) scheme consisting of a combination of time d...
In recent years, advances in immersive multimedia technologies, such as extended reality (XR) technologies, have led to more realistic and user-friendly devices. However, these devices are often bulky and uncomfortable, still requiring tether connectivity for demanding applications. The deployment of the fifth generation of telecommunications techn...
A cell-free non-coherent (NC) massive single-input-multiple-output (SIMO) system is proposed in a wireless uplink where a single-antenna user transmits to several multi-antenna access points (APs). NC detection using differential phase shift keying is the utilized detection technique in this system. It has the advantage that no channel state inform...
Non-coherent (NC) schemes combined with massive antenna arrays are proposed to replace traditional coherent schemes in scenarios which require an excessive number of reference signals, since NC approaches avoid channel estimation and equalization. Differential
M
-ary phase shift keying is one of the most appealing NC schemes due to its implementa...
Liquid-based antennas promise to overcome crucial limitations of traditional solid-based ones. Here, we describe different liquid antenna technologies that can be used to build arrays with the unprecedented flexibility and adaptivity needed to enable an evolution in wireless communications. We focus on two approaches that use either metallic or non...
The Reconfigurable Intelligent Surface (RIS) constitutes one of the prominent technologies for the 6th Generation (6G) of wireless communications. It is envisioned to enhance signal coverage in cases where obstacles block direct communication from Base Stations (BSs), and when high carrier frequencies are used that are sensitive to attenuation loss...
Many of the new mobile communication devices will
be things that power and monitor our homes, city infrastructure
and transport. Controlling drones thousands of miles away,
performing remote surgeries or being immersed in video with
no latency will also be a huge game changer. Those are some of
the few things that make the fifth generation (5G) a r...
Presents information and current topics of interest to the global communications industry.
The Reconfigurable Intelligent Surface (RIS) constitutes one of the prominent technologies for the next generation of wireless communications. It is envisioned to enhance the signal coverage in cases when the direct link of the communication is weak. Recently, beam training based on codebook selection is proposed to obtain the optimized phase confi...
Novel and cutting-edge use cases have arisen since the first deployments of the fifth generation of telecommunication networks (5G). There are plenty of well-though optimally design 5G simulators and emulators which allow telecommunication technologies engineers and researchers to thoroughly study and test the network. However, the 5G ecosystem is...
Presents information and current topics of interest to the global communications industry.
Reflecting Surfaces (RSs) are being lately envisioned as an energy efficient solution capable of enhancing the signal coverage in cases where obstacles block the direct communication from Base Stations (BSs), especially at high frequency bands due to attenuation loss increase. In the current literature, wireless communications via RSs are exclusive...
Augmented reality (AR) has been presented lately as one of the key technology fields in which 5G networks can become a disruptive tool, raising interest from both industry and academia. The main goal of this article is to extend the current state of the art of distributed AR studies and implementations by extracting the main AR algorithms' offloadi...
Reports on ComSoc global activities, events, and meetings.
It is a great honor and privilege for me to serve as the President of IEEE Communications Society (ComSoc) in 2022–2023. IEEE ComSoc is a global professional organization that has been creating cutting-edge communications and networking technologies through its high-quality publications, premier conferences, technology standards, educational activi...
The fifth-generation (5G) of networks is being deployed to provide a wide range of new services and to manage the accelerated traffic load of the existing networks. In the present-day networks, data has become more noteworthy than ever to infer about the traffic load and existing network infrastructure to minimize the cost of new 5G deployments. Id...
A novel time division duplex massive MIMO technique is proposed based on performing a pilot-less channel estimation in the uplink (UL) utilizing reconstructed differentially encoded data. Spatial multiplexing and differentially encoded data is applied both in the UL and in the downlink (DL). In this system, a reference signal is the first one of th...
The Reconfigurable Intelligent Surface (RIS) constitutes one of the prominent technologies for the next generation of wireless communications. It is envisioned to enhance the signal coverage in cases when the direct link of the communication is weak. Recently, beam training based on codebook selection is proposed to obtain the optimized phase confi...
Constant envelope orthogonal frequency division multiplexing (CE-OFDM) is a multi-carrier waveform with 0 dB peak-to-average power ratio (PAPR). This property enables the exploitation of multi-carrier waveforms with non-linear power amplifiers, avoiding the undesirable clipping effects. However, the existing channel estimation techniques designed f...
This paper introduces a novel waveform for wireless communication, denoted as Frequency-Modulated Orthogonal Frequency-Division Multiplexing (FM-OFDM). By frequency-modulating an OFDM signal and further defining a suitable cutoff subcarrier, the resulting constant-envelope waveform (ensuring a low Peak to Average Power Ratio) exhibits strong robust...
An advantage of using the composite fading models (CFMs) is their ability to concurrently address the impact of multi-path and shadowing phenomena on the system performance in wireless communications. A Fisher-Snedecor (FS) F CFM has been recently proposed as an experimentally verified and tractable fading model that can be efficiently applied for...
In 5G and beyond 5G networks, the new cell-less radio access network architecture is adopted to overcome the extreme network capacity challenges generated by massive wireless devices used for diverse scenarios and various applications. At the same time, the evolution of mobile communications faces the important challenge of increased network power...
Pilot-pouring superimposed training (PPST) is a novel channel estimation technique specially designed for cyclic block filtered multi-tone (CB-FMT), where the pilot symbols are poured into the subcarriers taking advantage of the power left unused by the data symbols. Hence, since this technique is based on superimposed training (ST) principles, the...
The Fisher–Snedecor (F-S) F distribution has recently been introduced as a tractable turbulence-induced (TI) fading model that fits well with the experimental data. This paper provides a performance evaluation of a free-space optical (FSO) re-configurable intelligent surface (RIS)-assisted communications (ACs) link over the F-S F TI fading channels...
This letter focuses on the pilot contamination problem in the uplink and downlink of cell-free massive multiple-input multiple-output networks with different degrees of cooperation between access points. The optimum minimum mean square error processing can take advantage of large-scale fading coefficients for canceling the interference of pilot-sha...
This letter focuses on the pilot contamination problem in the uplink and downlink of cell-free massive multiple-input multiple-output networks with different degrees of cooperation between access points. The optimum minimum mean square error processing can take advantage of large-scale fading coefficients for canceling the interference of pilot-sha...
Heterogenous networks are mainly limited by interference. Nowadays, the advances in reconfigurable antennas allow us to implement blind interference alignment (BIA) schemes, which avoid the need for channel state information at the transmitter (CSIT) while providing an increasing multiplexing gain, i.e., the achievable DoF, as the number of users i...
The FBMC is among the currently most researched techniques for signal processing and is explored here for passive optical access networks. This paper presents a performance analysis of the FBMC modulation format for applying in optical fiber and wireless communications. For analyzing, we realized simulation models that are based on well-known chara...
One of the main problems faced by communication systems is the presence of skip-zones in the targeted areas. With the deployment of the fifth-generation mobile network, solutions are proposed to solve the signal loss due to obstruction by buildings, mountains, and atmospheric or weather conditions. Among these solutions, reconfigurable intelligent...
Visible light communications (VLC) have been recently proposed to enhance the capacity of next generation of wireless services. Moreover, VLC networks usually comprise a large number of overlapping optical access points (APs). Moreover, each of these APs provides a small and confined area of coverage in order to generate satisfactory illumination....
The arrival of the fifth generation (5G) of mobile communications is boosting vehicular communications, an important use case addressed in the recent years. LTE introduced a sidelink radio interface through which user equipment would communicate directly with no necessary
dependence on the network, named PC5. 5G has defined its own sidelink interfa...
The Reconfigurable Intelligent Surface (RIS) constitutes one of the prominent technologies for the next 6-th Generation (6G) of wireless communications. It is envisioned to enhance signal coverage in cases where obstacles block the direct communication from Base Stations (BSs), and when high carrier frequencies are used that are sensitive to attenu...
Visible light communication (VLC) systems can support high data-rates for indoor communications. However, the inter-cell interference (ICI) in multi-cell VLC systems caused by resource sharing and the line-of-sight (LoS) blockage problem are significant challenges that cannot be neglected in the design and analysis of VLC systems. This letter studi...
Visible light communication (VLC) systems can support high data-rates for indoor communications. However, the inter-cell interference (ICI) in multi-cell VLC systems caused by resource sharing and the line-of-sight (LoS) blockage problem are significant challenges that cannot be neglected in the design and analysis of VLC systems. This letter studi...