M.O. Hasna

• PhD
• Professor at Qatar University

Despite the high data rates and security levels offered by free space optical (FSO) communication, its applications have been traditionally limited to point-to-point configurations due to the technology's narrow beamwidth and line-of-sight requirement. However, this research explores the potential of expanding FSO communication into more complex ne...

Terahertz (THz) communication is emerging as a key technology for future wireless systems due to its potential for ultra-high data rates and abundant bandwidth. However, THz communication faces significant challenges, including severe path loss, atmospheric absorption, and high sensitivity to misalignment and pointing errors. To address these chall...

In this paper, we establish a unified mathematical approach that connects the ergodic capacity of a wireless channel to the iterated Laplace transform of the channel's statistical characteristics. Particularly, we show that the ergodic capacity of any wireless channel can be interpreted as the iterated Laplace transform of the complementary cumulat...

In the pursuit of ubiquitous broadband connectivity, there has been a significant shift towards the vertical expansion of communication networks into space, particularly through the exploitation of low Earth orbit (LEO) satellite constellations, which are favored for their relatively low latency. However, this approach faces many challenges that ne...

We provide an analytic framework for the capacity of adaptive transmission techniques, taking into account both generalized fading channels and Gaussian-distributed transceiver hardware impairments (THI). We derive exact expressions for the capacity of optimal power and rate adaptation, optimal rate adaptation with constant power, channel inversion...

In this paper, rate splitting (RS) has been applied in a mixed dual-hop radio frequency/free space optical (RF/FSO) relay system. In particular, assuming fixed-gain amplify-and-forward (AF) and decode-and-forward (DF) relay protocols, the performance of both heterodyne detection and intensity-modulated direct detection (IM-DD) has been analytically...

Combining free-space optical (FSO) technology with unmanned aerial vehicles (UAVs) introduces dynamic, rapidly deployable relay systems, overcoming line-of-sight (LoS) constraints and extending high-speed communication networks’ reach, albeit with critical considerations of weight and power consumption. There are two main types of optical communica...

Unmanned aerial vehicles (UAVs) are increasingly being utilized as mobile base stations for rapidly establishing temporary wireless coverage in emergency situations and remote locations. Their high mobility and flexibility make UAVs ideal for quickly deployed communication systems, but these features also introduce unique challenges, particularly i...

This paper explores the deployment of Unmanned Aerial Vehicles (UAVs) for Terahertz (THz) communication within complex three-dimensional environments, particularly focusing on disaster-stricken areas. Utilizing THz communication's high data rates and the need for direct Line-of-Sight (LoS), our approach involves a dynamic and real-time 3D mapping t...

Data rate, security, spectral efficiency, energy efficiency and reliability represent the main requirements in most of communication systems. Different wireless technologies can achieve different levels of these requirements, where a specific wireless technology cannot individually attain the best performance in all of these system requirements. Fr...

Terahertz (THz) links require a line-of-sight (LoS) connection, which is hard to be obtained in most scenarios. For THz communications, analyses based on LoS probability are not accurate, and a real LoS model should be considered to determine the LoS status of the link in a real 3D environment. Considering unmanned aerial vehicle (UAV)-based THz ne...

In this work, the implementation of a Non-Orthogonal Multiple Access (NOMA) scheme over directional Terahertz (THz) links is studied. It is well known that for directional THz antennas, precise alignment between antennas is a major requirement. However, for dynamic systems with mobile nodes, positioning and antenna alignment are continuous processe...

In this paper, we investigate the performance of a wireless communication system based on thermal noise modulation (TNM). In this system, the information is encoded in the variance of the thermal noise, enabling highly efficient low-power transmission. To assess the performance of the TNM scheme, we derive an exact closed-form expression for the bi...

In this paper, we investigate the performance of a wireless communication system based on thermal noise modulation (TNM). In this system, the information is encoded in the variance of the thermal noise, enabling highly efficient low-power transmission. To assess the performance of the TNM scheme, we derive an exact closed-form expression for the bi...

Unmanned Aerial Vehicles (UAVs) have emerged as a critical component in next-generation wireless networks, particularly for disaster recovery scenarios, due to their flexibility, mobility, and rapid deployment capabilities. This paper focuses on optimizing UAV trajectories to ensure effective communication in disaster-stricken areas using terahertz...

In this paper, we study the performance of a cooperative underwater acoustic communication/free-space optical communication (UAC-FSO) transmission system supported by a fixed-gain amplify-and-forward (AF) relay, where an underwater source transmits signals to a satellite through the help of a buoy functioning as a relay located on the sea surface....

We explore THz communication uplink multi-access with multi-hop Intelligent reflecting surfaces (IRSs) under correlated channels. Our aims are twofold: 1) enhancing the data rate of a desired user while dealing with interference from another user and 2) maximizing the combined data rate. Both tasks involve non-convex optimization challenges. For th...

Two-Way Relaying (TWR) is an efficient relaying technique that doubles the spectral efficiency as compared to the traditional one-way relaying. As such, it has been nominated as a solution to extend the coverage of links operating on the Millimeter Wave (mmWave) band. In this paper, the performance of TWR is investigated for mmWave-based aerial lin...

In this article, our target is to design a permanent long backhaul link using unmanned aerial vehicle (UAV) relays and charge stations (CSs) to transfer data from the nearest core network to disaster area (DA). To this end, we first characterize the communication channel by considering the energy consumption models of the backup UAVs (moving UAVs)...

This paper focuses on the optimal design of a modulated retroreflector (MRR) laser link to establish a high-speed downlink for cube satellites (CubeSats), taking into account the weight and power limitations commonly encountered by these tiny satellites. To this end, first, a comprehensive channel modeling is conducted considering key real channel...

With the vast proliferation of smart mobile devices, there is an ever-increasing demand for higher data rates and seamless connectivity throughout. Current 5th generation and beyond (B5G) cellular networks struggle to eradicate outage zones and ensure seamless connectivity. One promising solution to this problem is the use of unmanned aerial vehicl...

High-altitude platform (HAP) stations are pivotal in non-terrestrial networks, enhancing communication capabilities and extending cost-effective network access to rural or remote areas. HAP-assisted free-space optical (FSO) communications provide a promising solution for improving data rates. To safeguard against eavesdropping, especially during em...

Given the growing significance of CubeSats for real-time Earth monitoring and space networking, there is an increasing demand for high-speed links for CubeSats facing constraints related to the weight, dimensions, and power consumption of telecommunication equipment. This article addresses such a need by designing a modulating retroreflector (MRR)-...

Free-space optical (FSO) links based on Modulating Retroreflectors (MRRs) present an attractive solution for unmanned aerial vehicle (UAV) communications due to their weight and power consumption benefits. However, they face a significant security challenge since any unauthorized user within the MRR’s Field-of-View (FoV) can access the channel info...

In this work, we investigate the performance of free space optical (FSO) communication systems based on modulating retroreflector (MRR) array. In particular, we first characterize the MRR array-based FSO channel by taking into account the effects of real channel parameters. Then, we derive the analytical expressions for the probability density func...

This paper investigates the problem of data routing in backhaul networks using Unmanned Aerial Vehicles (UAVs) to relay data from Small Cells (SCs) to the core network. The objective is to maximize the total demand of data to be routed, while ensuring technical requirements such as hop constraints and edge capacity. The problem is formulated using...

We propose a fixed-wing unmanned aerial vehicles (UAV)-based millimeter wave (mmWave) backhaul architecture that is offered as a cost effective and easy to deploy solution, to connect a disaster or remote area to the nearest core network. First, we fully characterize the single relay fixed-wing UAV-based communication system by taking into account...

p>In this paper, a dynamic unmanned aerial vehicle (UAV)-based heterogeneous network (HetNet) equipped with directional terahertz (THz) antennas is studied to solve the problem of transferring massive traffic of distributed small cells to the core network.</p

p>In this paper, a dynamic unmanned aerial vehicle (UAV)-based heterogeneous network (HetNet) equipped with directional terahertz (THz) antennas is studied to solve the problem of transferring massive traffic of distributed small cells to the core network.</p

p>The main subject of this work is to make a detailed comparison between the performance of free-space optical (FSO) and terahertz (THz) links under different conditions. </p

p>In this article, our goal is to design a permanent long backhaul link using unmanned aerial vehicle (UAV) relays and charge stations (CSs) to transfer data from the nearest core network to disaster area.</p

p>This letter addresses the impact of the hardware impairments on the data transmission over Terahertz (THz) band.</p

p>In this work, we investigate the performance of free space optical (FSO) communication systems based on modulating retroreflector (MRR) array.</p

p>In this work, we investigate the performance of free space optical (FSO) communication systems based on modulating retroreflector (MRR) array.</p

p>In this article, our goal is to design a permanent long backhaul link using unmanned aerial vehicle (UAV) relays and charge stations (CSs) to transfer data from the nearest core network to disaster area.</p

p>This letter addresses the impact of the hardware impairments on the data transmission over Terahertz (THz) band.</p

p>The main subject of this work is to make a detailed comparison between the performance of FSO and terahertz (THz) links under different conditions. </p

In this work, we investigate a novel covert communication system, where the legitimate transmitter attempts to communicate with a covert user in the presence of a warden and the public user covertly. Specifically, the legitimate transmitter employs non-orthogonal multiple access (NOMA) and rate-splitting (RS) to communicate with users aided by a re...

The third-generation partnership project (3GPP) defined several scenarios of vehicle-to-everything (V2X) networks such as vehicle-to-vehicle, vehicle-to-pedestrian, and vehicle-to-infrastructure. Unmanned aerial vehicles (UAVs) exploiting such scenarios for vehicular applications like vehicular-platooning, autonomous driving, and traffic management...

p>Manuscript on using Reinforcement Learning to control the phases of cascaded intelligent reflective surfaces to maximize received rate of multiple access Terahertz communication.</p

We investigate THz communication uplink multiple access using cascaded intelligent reflecting surfaces (IRSs) assuming correlated channels. Two independent objectives to be achieved via adjusting the phases of the cascaded IRSs: 1) maximizing the received rate of a desired user under interference from the second user and 2) maximizing the sum rate...

This paper focuses on providing an analytical framework for the quantification and evaluation of high-directional terahertz communication links under pointing errors in terms of outage probability (OP), channel capacity, and symbol error rate (SER). To this end, the probability density function and cumulative distribution function of the end-to-end...

Networked flying platforms (NFPs) have emerged as a favorable solution to extend the network coverage and/or capacity in temporary scenarios, such as disasters or mega-size events, thanks to their flexibility and cost efficiency. However, in order to provide a reliable multihop link through NFPs, multiple parameters should be considered and optimiz...

Recent developments in Unmanned Aerial Vehicles (UAVs) technology have paved the way to their utilization in different fields and applications. Among these applications, UAVs have been widely investigated as a good candidate to serve as mobile base-stations that can provide prompt and temporary coverage of wireless connectivity for specific areas....

In this paper, a dynamic unmanned aerial vehicle (UAV)-based heterogeneous network (HetNet) equipped with directional terahertz (THz) antennas is studied to solve the problem of transferring massive traffic of distributed small cells to the core network. To this end, we first characterize a detailed three-dimensional (3D) modeling of the dynamic UA...

This letter focuses on providing an analytical framework for the quantification and evaluation of the pointing error at high-frequency millimeter wave (mmWave) and terahertz (THz) communication links. For this aim, we first characterize the channel of a point-to-point communication link between unstable transmitter (Tx) and receiver (Rx) and then,...

There are two approaches well known in the literature for reducing the complexity in averaged performance analyses of wireless communications systems (i.e., for alleviating the computational difficulty in averaged performance evaluations). The first method, known as the moment generating function MGF-based approach, aims to convert the instantaneou...

Weight reduction and low power consumption are key requirements in the next generation of unmanned aerial vehicle (UAV) networks. Employing modulating retro-reflector (MRR)-based free space optical (FSO) technology is an innovative technique for UAV-to-ground communication in order to reduce the payload weight and power consumption of UAVs which le...

This paper focuses on providing an analytical framework for the quantification and evaluation of the pointing error for a general case at high-frequency millimeter wave (mmWave) and terahertz (THz) communication links. For this aim, we first derive the the probability density function (PDF) and cumulative distribution functions (CDF) of the pointin...

In this paper, an unmanned aerial vehicles (UAV)-based heterogeneous network is studied to solve the problem of transferring massive traffic of distributed small cells to the core network. First, a detailed three-dimensional (3D) model of the downlink channel is characterized by taking into account the real antenna pattern, UAVs' vibrations, random...

Orthogonal time frequency space (OTFS) modulation is a recent technology that offers a significant advantage on link reliability due to its strong delay-Doppler resilience. In classical cellular technology, overall system performance is limited by the fading and interference experienced by particular user equipment (UE) over its radio resources (RR...

This paper focuses on providing an analytical framework for the quantification and evaluation of the pointing error at high-frequency millimeter wave (mmWave) and terahertz (THz) communication links. For this aim, we first characterize the channel of a point-to-point communication link between to unstable transmitter (Tx) and receiver (Rx) and then...

In this study, we consider an unmanned aerial vehicle (UAV)-assisted heterogeneous network that is offered as a cost-effective and easy to deploy solution to solve the problem related to transferring traffic of distributed small cells to the core network. For any given distribution of small cell base stations (SBSs), we first characterize an accura...

We propose a fixed wing unmanned aerial vehicles (UAV)-based millimeter wave (mmWave) backhaul links, that is offered as a cost effective and easy to deploy solution, to connect a disaster or remote area to the nearest core network. First, we fully characterize the single relay fixed-wing UAV-based communication system by taking into account the ef...

The main contribution of this paper is to analyze a long networked flying platform (NFP)-based millimeter wave (mmWave) backhaul link that is offered as a cost effective and easy to deploy solution to connect a disaster or remote area to the nearest core network. For this aim, we characterize the backhaul channel as a function of realistic physical...

This paper discusses the analysis of a fixed-wing unmanned aerial vehicle (UAV)-based millimeter wave (mmWave) backhaul link, that is offered as a cost-effective and easy deploy the solution to connect a disaster or remote area to the nearest core network. We present the optimal design of a relay system based on fixed-wing UAV, taking into account...

Weight reduction and low power consumption are key requirements in the next generation of unmanned aerial vehicle (UAV) networks. Employing modulating retro-reflector (MRR)-based free space optical (FSO) technology is an innovative technique for UAV-to-ground communication in order to reduce the payload weight and power consumption of UAVs which le...

Unmanned aerial vehicle (UAV) relaying is deemed as a promising solution to enhance the achievable rate and widespread connectivity in millimeter-wave (mm-wave) systems for tomorrow’s 6G wireless networks. In this paper, we study both the performance and user association optimization for the UAV relay-assisted mm-wave massive multiple-input multipl...

In this study, we consider an unmanned aerial vehicle (UAV)-assisted heterogeneous network that is offered as a cost effective and easy to deploy solution to solve the problem related to transferring traffic of distributed small cells to the core network. For any given distribution of small cell base stations (SBSs), we first characterize an accura...

This paper focuses on providing an analytical framework for the quantification and evaluation of the pointing error for a general case at high-frequency millimeter wave (mmWave) and terahertz (THz) communication links. For this aim, we first derive the probability density function (PDF) and cumulative distribution functions (CDF) of the pointing er...

In this paper, an unmanned aerial vehicles (UAV)-based heterogeneous network is studied to solve the problem of transferring massive traffic of distributed small cells to the core network. First, a detailed three-dimensional (3D) model of the downlink channel is characterized by taking into account the real antenna pattern, UAVs' vibrations, random...

As a last resort for radio frequency communication, Terahertz bands (0.1-10 THz) are targeted thanks to their ability to provide ultra-wide bandwidth satisfying varieties of emerging applications. However, the waves propagating at THz frequencies suffer from high losses due to absorption in air molecules which forces their use into short-range link...

In this paper, we study the secrecy performance of an unmanned aerial vehicle (UAV)-assisted relay communication system, where a ground base station (GBS) intends to send confidential information to the ground legitimate user Bob with the help of a UAV relay in the presence of multiple aerial and ground eavesdroppers. We consider the height-depende...

Although Geostationary-Equatorial-Orbit (GEO) satellites have achieved significant success in conducting space missions, they cannot meet the 5G latency requirements due to the far distance from the earth surface. Therefore, Low-Earth-Orbit (LEO) satellites arise as a potential solution for the latency problem. Nevertheless, integrating the 5G terr...

In this work, in order to achieve higher spectrum efficiency, we propose a reconfigurable intelligent surface (RIS)-assisted multi-user communication uplink system. Different from previous work in which the RIS only optimizes the phase of the incident users’ signal, we propose the use of the RIS to create a virtual constellation diagram to transmit...

Securing wireless communication using different techniques has been an interesting topic for research, especially with the increasing demand on fast and secure transmission. In this research, we conduct a performance analysis on a UAV based system in the presence of a ground eavesdropper/jammer operating in full-duplex mode, where a legitimate tran...

In the next generations of communication systems, resources’ scarcity devolves to a more critical point as a consequence of the expected massive number of users to be served. Furthermore, the users’ contradicting requirements on quality of service forces the network to behave in a dynamic way in terms of the multiple access orchestration and resour...

In this work, in order to achieve higher spectrum efficiency, we propose a reconfigurable intelligent surface (RIS)-assisted multi-user communication uplink system. Different from previous work in which the RIS only optimizes the phase of the incident users's signal, we propose the use of the RIS to create a virtual constellation diagram to transmi...

Unlike orthogonal multiple access schemes, non-orthogonal (NOMA) ones have arisen as an appealing solution to meet the requirements of the upcoming era of massive connectivity. In NOMA schemes, users are allowed to restrainedly interfere. Therefore, NOMA’s ability to serve a number of users more than the number of available orthogonal channels has...