Characteristics Of Communication Channel Research Articles

Assessment of Communication Resource Allocation by the Transmission Control Protocol for the Target Virtual Connection under Competitive Conditions

The mathematical framework presented in this article focuses on the controlled-transmission protocol’s asynchronous process of bandwidth allocation for the target virtual connection implemented under competition for communication resources. The studied process is formalized as a two-dimensional discrete Markovian chain, taking into account the distributions of queue lengths of TCP data fragments from competing client nodes. Such a chain describes the dynamics of filling the stack of transmitted but unacknowledged data fragments of the investigated end device. Distributions of the chain states were found for various ratios of the target virtual-connection bandwidth, transmission-protocol parameters, and communication-channel characteristics. Analytical dependencies for computing the performance of the target virtual connection for different operating modes were obtained. The results of experiments conducted based on the obtained analytical constructions showed that the performance of the virtual connection with a selective repeat mode is mainly determined by the data-loss intensity, the queue size distribution in transit nodes, and the ratio between the protocol window size and the route length.

Modeling and oblique transmission characteristics of an underwater wireless optical communication channel based on ocean depth layering.

Underwater wireless optical communication is widely considered in the field of underwater communication due to its high bandwidth and low latency. In a real transmission link, the temperature and salinity of seawater, chlorophyll concentration, and bubble density vary with ocean depth. Therefore, the depth of the optical transmitter in seawater and the tilt angle of the beam will exhibit different beam transmission characteristics. In this paper, an underwater oblique-range layered channel model considering the combined effects of dynamic turbulence, absorption, and scattering is developed based on real data of seawater at different depths measured by the Global Ocean Observing Buoy Argo and the Woods Hole Oceanographic Institution BCO-DMO. The effects of transmission distance, transmitter tilt angle, and transmitter depth on the oblique-range transmission characteristics of the beam in seawater are discussed. The simulation results show that, at the same transmission distance, the beam centroid displacement increases with an increase in transmitter depth only when the transmitter is located above the interior of the thermocline. When the transmitter is located below the interior of the thermocline, the influence of the transmitter tilt angle on the beam centroid displacement decreases. This indicates that at different depths within the interior of the thermocline, the optical beam transmission characteristics exhibit significant variations.

ADOPTION AND DIFFUSION OF AGRICULTURAL TECHNOLOGICAL INNOVATIONS GOVERNMENT PROGRAM FIELD SCHOOL INTEGRATED PARTICIPATORY DEVELOPMENT MANAGEMENT OF IRRIGATION PROGRAM (IPDMIP)

This research details efforts to analyze the adoption and diffusion of agricultural technology innovations through the Integrated Participatory Development Management of Irrigation Program (IPDMIP) Field School Program in Kedungreja District, Cilacap Regency. In the background, the urgency of agriculture as the primary sector in development is illustrated, with technology adoption being the key to increasing productivity and farmer welfare. The IPDMIP program emphasizes the involvement of farmers in irrigation management and implementing modern technology to optimize agricultural yields. However, there has not been much in-depth research on the factors that influence the successful adoption and diffusion of technological innovations in the context of this program. This research aims to identify the factors that influence the adoption and diffusion of agricultural technology innovations in the IPDMIP Field School while measuring the adoption and diffusion of these innovations in the Kedungreja District. The quantitative research method uses a survey approach and statistical data analysis. The research instrument includes variables such as cultivated area, farmer age, education level, innovation characteristics, characteristics of potential users, decision-making, communication channels, and instructor qualifications. Data was collected from 100 respondents who were members of farmer groups receiving IPDMIP Field School activities through questionnaires. Data analysis shows that the IPDMIP Field School Program effectively increases the adoption and diffusion of agricultural technology innovations in the Kedungreja District. Factors such as farmer age, characteristics of the innovation, characteristics of potential users, and communication channels play a significant role in the successful adoption and diffusion of the innovation. The research results provide an in-depth picture of the effectiveness of this program in bringing positive change among farmers. This conclusion can be a basis for formulating further policies to support sustainable agricultural development and improve farmer welfare.

Method for evaluation of the optical uniformity distribution in the white LEDs-based visible light communication applications

The uniformity characteristic of emitted radiation in VLC applications is a factor that can affect the efficiency of a detector and the overall efficiency of the VLC system. In this paper, we theoretically investigate the optical uniformity characteristic of using LEDs in VLC applications in terms of the parameter of the emission angle of LEDs and the spatial distribution of LEDs. The result indicates that the optical uniformity can be controlled at a high level by controlling the emission angle of the LED or distributing the LEDs in the room's space. Full Text: PDF References E.-F. Schubert, J.-K. Kim, "Solid-State Light Sources Getting Smart", Science 308, 1274 (2005). CrossRef N. Narendran, Y. Gu, "Life of LED-based white light sources", J. Display Technol. 1, 167 (2005). CrossRef E. Schubert, Light-Emitting Diodes (Cambridge, Cambridge Univ. Press 2006). CrossRef C.C. Sun, Q.K. Nguyen, T.X. Lee, S.K. Lin, C.S. Wu, T.H. Yang, Y.W. Yu, "Active thermal-fuse for stopping blue light leakage of white light-emitting diodes driven by constant current", Sci. Reports 12, 12433 (2022). CrossRef Z. Ghassemlooy, W. Popoola, S. Rajbhandari. Optical Wireless Communications System and Channel Modelling with MATLAB (Florida, CRC Press, Taylor & Francis Group, 2013). CrossRef A. Burton, H. Le Minh, Z. Ghasemlooy, S. Rajbhandari, "A study of LED lumination uniformity with mobility for visible light communications", IEEE 2012 Int. Workshop on Opt. Wireless Comm. (IWOW), Pisa, Italy, 2012. CrossRef M.S.M. Gismalla, M.F.L. Abdullah, M.I. Niass, B. Das, W.A. Mabrouk. "Effect of optical attocells deployment on the RMSD spread in indoor visible light communication systems", Int. J. Commun Syst. e4349 (2020). CrossRef C. Wang, J. Wang, J. Zhang, J. Wang, H. Du, J. Wang, "Research on uniform illumination distribution of indoor visible light communication", Proc. SPIE 12062, AOPC 2021: Optoelectronics and Nanophotonics (2021). CrossRef M.V. Bhalerao, M. Sumathi, S.S. Sonavane. "Line of sight model for visible light communication using Lambertian radiation pattern of LED", Int. J. Comm. Systems (2016). CrossRef J.F. Zang, Y. Piao. "Research on visible light communication system based on white LEDs", Proc. SPIE 10255, (2016). CrossRef M. Oliveira, F.C.B. Tosta, D.E.F. Guillen, P.P. Monteiro, A.A.P. Poh, "Theoretical and Experimental Analysis of LED Lamp for Visible Light Communications", Wireless Personal Communications 125, 3461(2022). CrossRef J.P. Ding, C. Lin, J.T. Wang, H. Yang, "Effects of Optical Beams on MIMO Visible Light Communication Channel Characteristics", Sensors 22, 216 (2022). CrossRef X. Zhang , N. Zhao, F. Al-Turjman, M.B. Khan, X. Yang. "An Optimization of the Signal-to-Noise Ratio Distribution of an Indoor Visible Light Communication System Based on the Conventional Layout Model", Sustainability 12, 9006 (2020). CrossRef A. Kaewpukdee, P. Uthansakul, "Characteristic of Line-of-Sight in Infrastructure-to-Vehicle Visible Light Communication Using MIMO Technique", Materials Continua 74, 1026 (2023). CrossRef

Micro-hydro Power Plant-Based Social Entrepreneurship Practices in Rural West Java (A Case Study of Cintamekar Village, Subang Regency)

Cintamekar Village in Subang Regency, West Java, is a peripheral village. One of its characteristics is that residents, especially from the pre-prosperous group, have not been able to enjoy the flow of electricity even though the source of electricity through the PLN is available. To overcome this, on the initiative of the non-governmental organization Initiative of People's Business and Economy (IBEKA), a PLTMH was built in the area. The purpose of this research is to analyze factors affecting social entrepreneurship for community empowerment. The research uses a quantitative approach which is reinforced by qualitative data. The method chosen is the case study. The results showed that overall, the formation of cooperatives was able to build social entrepreneurship by creating social benefits (score 3.6), carrying out social innovation (score above 3), and making the economic activities of citizens more diverse (score 4). The results from the data processed using SEM-PLS show that the development of social entrepreneurship is influenced by the characteristics of technology and innovation by 0.281. The communication channel factor is more dominant in influencing the development of social entrepreneurship, which is equal to 0.487. These two factors explained that there was a change of 33.3 percent in social entrepreneurship. The social entrepreneurship practice of the PLTMH program in Cintamekar Village is built on the characteristics of technology, innovation, and communication channels. The characteristics of technology and innovation as well as communication channels are the driving force for residents to change their social entrepreneurship behavior. This means that the technological and innovation characteristics of the PLTMH development and the communication channels used, through cooperative institutions, have a good impact on the development of social entrepreneurship in Cintamekar Village, and as a whole, they are able to build social entrepreneurship in creating social innovation and economic activities.

Analysis of High-Frequency Communication Channel Characteristics in a Typical Deep-Sea Incomplete Sound Channel

Deep-sea acoustic communication has attracted widespread attention in recent years. Research on deep-sea acoustic communication channel characteristics is essential for the development and system design of deep-sea acoustic communication technologies. However, the structural and spatiotemporal characteristics of deep-sea high-frequency acoustic communication channels (unlike those of shallow-water acoustic communication channels) are poorly understood. Based on a channel measurement experiment in a typical deep-sea incomplete sound channel environment in the South China Sea, this paper analyzes the structural and spatiotemporal characteristics of high-frequency underwater acoustic channels in the direct-arrival and shadow zones. The channel multipath vertical structure, amplitudes of different path clusters, root mean square (RMS) delay spread, and channel temporal coherence are investigated at different depths. The randomness of different path clusters is quantified as the coefficient of variation. The channels in the shadow zone are characterized by a complex multi-path structure, high RMS delay spread, and low temporal coherence. On the contrary, the channels of the direct-arrival zone show multi-path convergence, low RMS delay spread, and high temporal coherence. Understanding the dynamic changes in these parameters can guide the statistical modeling of channels and the design of communication algorithms in different zones in deep-sea high-frequency acoustic communication scenarios.

DRL-Based Hybrid Task Offloading and Resource Allocation in Vehicular Networks

With the explosion of delay-sensitive and computation-intensive vehicular applications, traditional cloud computing has encountered enormous challenges. Vehicular edge computing, as an emerging computing paradigm, has provided powerful support for vehicular networks. However, vehicle mobility and time-varying characteristics of communication channels have further complicated the design and implementation of vehicular network systems, leading to increased delays and energy consumption. To address this problem, this article proposes a hybrid task offloading algorithm that combines deep reinforcement learning with convex optimization algorithms to improve the performance of the algorithm. The vehicle’s mobility and common signal-blocking problems in the vehicular edge computing environment are taken into account; to minimize system overhead, firstly, the twin delayed deep deterministic policy gradient algorithm (TD3) is used for offloading decision-making, with a normalized state space as the input to improve convergence efficiency. Then, the Lagrange multiplier method allocates server bandwidth to multiple users. The simulation results demonstrate that the proposed algorithm surpasses other solutions in terms of delay and energy consumption.

Characterization and modeling of high-speed underwater acoustic communication channels

High-speed mobile underwater acoustic communication (HSM-UAC) is a relatively unexplored terrain, but its importance is expected to increase with the widespread application of flexible underwater mobile platforms such as AUVs and UUVs. Knowledge of HSM-UAC channels is a prerequisite to achieving reliable communication. This work conducted two HSM-UAC channel measurement experiments with a maximum speed of 20knots. The analysis of channel time-varying characteristics demonstrates the shortcomings of traditional consistent Doppler frequency offset channel model. The experimental findings reveal the presence of two non-stationary modes in the HSM-UAC channel. For short moving distances, the changes in channel geometry result in each path experiencing a different Doppler scale, thus observing the multiscale-multilag (MSML) channels. For long moving distances, the alteration in sound ray propagation tracks entirely reshapes the channel impulse response (CIR) structure, leading to a rapid decline in channel time correlation. In further analysis, the correlation coefficient of the power delay profile (PDP) is used to measure channel stationarity. Subsequently, the stationary time and corresponding stationary distance are calculated as characterization parameters for the time-varying channel model. The quantitative evaluation results are helpful for the communication signal design and determining the update frequency of channel state information.

Channel characteristics of underwater optical communication system

Underwater communication technology has seen significant development in recent years, with a focus on finding efficient and secure techniques for exploring the underwater world. While acoustic and electromagnetic waves have limitations in water, the use of optical communication has become a focus of research due to its high bandwidth and low delay. Research has shown that blue and green lights are absorbed less than other wavelengths in water, making them suitable for underwater optical communication. In recent years, people have been working with optical communication in harsh environments. The optical system and the acoustic system have been combined to achieve certain development. Several high-speed underwater laser transmission systems have also been developed, with varying transfer rates and distances. This paper focuses on the theory of underwater optical systems and their communication channel characteristics.

Channel modeling for V2V communication: Enhancing road safety and intelligent transportatio

The advancement of the Internet of Things (IoT) and Vehicle-to-Vehicle (V2V) communication networks has led to increased research efforts toward developing efficient and innovative V2V communication systems. These systems are designed to achieve the goal of improving road safety and enabling intelligent transportation. A critical aspect of this effort is channel modeling. In this context, this paper summarizes the characteristics of V2V communication channels. It categorizes them into three main types: Deterministic models, Non-geometry stochastic models (NGSMs), and Geometry-based stochastic models (GBSMs). It then reviews recent literature on these three types of channel modeling methods and discusses future development directions and challenges for V2V channel modeling. The study highlights the importance of accurate channel modeling for successful V2V communication systems and emphasizes the need to consider the unique features of V2V channels. It also identifies the limitations of existing channel models and suggests areas of research that can lead to more reliable and efficient V2V communication systems.

FEATURE SUPPLICATION AND CLASSIFICATION MARITIME UNMANNED SURFACE VESSELS IN UKRAINE NAVAL FORCES

The work examines the relevance of the issue of the comprehensive development of the class of unmanned surface vehicles for the implementation of civil and military tasks at sea. The list of tasks that can be most successfully solved using unmanned surface vehicles has been determined. The most typical and relevant tasks at sea are various monitoring activities, search operations in accident areas, support of industrial activities, compilation and refinement of models of the sea floor relief, coastline, and so on. The circle of relevant military tasks has also been outlined, namely reconnaissance, damage to the enemy, protection of coastal areas, setup of mines, mine countermeasures, delivery of personnel and cargo to designated areas, and so on. An analysis of the characteristics of existing unmanned surface vehicles of the leading countries of the world has been conducted, as well as the possibilities of their application for the performance of a wide range of civil tasks at sea and features of their use as vehicles for carrying out military missions. It has been determined that in the process of further development, the main priorities are seen as increasing autonomy, equipping unmanned surface vehicles with modular executive systems, introducing artificial intelligence for direct control of unmanned vehicles and weapons, increasing the system's survivability, improving the technical characteristics of communication channels for information and task exchange. Currently, the most relevant channel for control is considered to be the satellite communication channel, as it is distance-independent, resistant to jamming and interception, and does not require significant energy consumption. Proposals have been made regarding the distribution of unmanned surface vehicles into classes, namely small, medium, and large, which cover all existing types of unmanned surface vehicles. The main terms and definitions of unmanned surface vehicles that are using in NATO countries have also been analyzed, and the main terms and definitions in this direction have been proposed. The purpose of the article is to make proposals for the development of unmanned surface vehicles and to identify promising areas for their use in solving various tasks at sea.

Information Technology for Maximizing Energy Consumption for Useful Information Traffic in a Dense Wi-Fi 6/6E Ecosystem

In Wi-Fi standards, a relatively narrow range of frequency spectrums is declared as working, on the operation of which additional restrictions are imposed in different countries. When creating dense wireless network ecosystems focused on massive information traffic, this circumstance causes significant interference even in the case of using Wi-Fi 6/6E-compatible equipment. An effective solution to this problem is the implementation of a centralized management mechanism for the relevant parameters of the target network ecosystem. The growing attention to ecology and rational use of electricity makes the problem of maximizing energy consumption for useful information traffic in a dense Wi-Fi 6/6E ecosystem an urgent task. Only the addressed information traffic between the transmitter and the target subscriber, which are subjects of the OFDMA technology and the MU-MIMO multiple access system (with an emphasis on the latter), is considered useful. To solve the problem, the authors formalized the Wi-Fi 6/6E ecosystem’s energy consumption model, which takes into account the specifics of OFDMA and MU-MIMO, the influence of the communication channel characteristics on the speed of target information transfer, and detailed energy consumption for maintaining the network infrastructure in a functional state. Based on the created model, the research problem is represented by the difference between two monotonic functions, relative to which the problem of optimization with restrictions is set. The process of solving this problem is presented in the form of information technology with a branch-and-bound hierarchy and a nested unconditional optimization problem. The results of simulated modelling in the MATLAB-NS3 environment showed a significant advantage of the authors’ approach. The energy power consumption by the Wi-Fi 6/6E ecosystem, the parameters of which were adjusted with the help of the authors’ information technology, decreased by more than four times.

Channel Characterization and Modeling for 6G UAV-Assisted Emergency Communications in Complicated Mountainous Scenarios.

Regarding the new demands and challenges of sixth-generation (6G) mobile communications, wireless networks are undergoing a significant shift from traditional terrestrial networks to space-air-ground-sea-integrated networks. Unmanned aerial vehicle (UAV) communications in complicated mountainous scenarios are typical applications and have practical implications, especially in emergency communications. In this paper, the ray-tracing (RT) method was applied to reconstruct the propagation scenario and then acquire the wireless channel data. Channel measurements are also conducted in real mountainous scenarios for verification. By setting different flight positions, trajectories, and altitudes, channel data in the millimeter wave (mmWave) band was obtained. Important statistical properties, such as the power delay profile (PDP), Rician K-factor, path loss (PL), root mean square (RMS) delay spread (DS), RMS angular spreads (ASs), and channel capacity were compared and analyzed. The effects of different frequency bands on channel characteristics at 3.5 GHz, 4.9 GHz, 28 GHz, and 38 GHz bands in mountainous scenarios were considered. Furthermore, the effects of extreme weather, especially different precipitation, on the channel characteristics were analyzed. The related results can provide fundamental support for the design and performance evaluation of future 6G UAV-assisted sensor networks in complicated mountainous scenarios.

Detection of abnormal situations in the operation of communication channels

Currently, many countries have high expectations for the digitalization of economies, meaning various elements of automation. One of the most effective tools in achieving a new level of digitalization can be the Internet of Things (IoT). The development of IoT provokes the fourth industrial revolution (Industry 4.0), which will be marked by the transition to fully automated digital production, the use of cyber-physical systems and cloud computing. Processes will be controlled by "smart" devices online. An example of such smart devices is modern telecommunications equipment, the operation of which accumulates large amounts of data - telemetry of various kinds. This "big data" can be used to predict possible future failures and other faults (abnormal situations) in the equipment itself. This article is devoted to the issue of creating models of normal behavior of various characteristics of communication channels, which is central in creating predictive diagnostics systems. Examples of such models are given.

A COMPARATIVE ANALYSIS OF COST 231 AND HATA MODELS WITH MEASURED PATH LOSS FOR SOKOTO METROPOLIS (A CASE STUDY OF MTN)

For optimal characterization of radio communication channel, key parameters and a mathematical model are essential for predicting or determining the signal coverage, channel efficiency and capacity. Path loss prediction plays a basic role in planning and designing of every radio communication link. This paper investigates a suitable model capable of planning a better global system for mobile communication (GSM) network (MTN) with a view to address numerous complain of poor quality service by the subscribers, within Sokoto city using measuring tape, Basic Transreceiver System (BTS) app on mobile phone and mobile device distance. Received Signal Strength (RSS) were obtained from MTN base stations (network) located in State and path loss was analyzed. The experimental measurement of path loss was compared to theoretical models of COST231 and Hata models. The results showed that the COST231 was found most suitable path loss prediction model for Sub-urban region of Sokoto based on the validation test; however, the Hata model also produces reasonable estimates and can be use for path loss prediction model in the location.

Envelope distribution and Doppler spectrum of V2V channels at 5.9 GHz in mountainous roads

Land transportation of people and goods often relies on strategic routes that pass through mountains. Despite the importance of these routes, the characteristics of the vehicular radio communication channel in such environments have received little attention. To close the gap, this paper presents the results of a measurement campaign at 5.9 GHz in mountainous roads. Data collected during the measurement campaign were used to quantify the envelope distribution and Doppler spectrum of small-scale vehicle-to-vehicle (V2V) communication channels. The measurements were taken in three different locations, two in San Luis Potosí (SLP), México, and one near Provo, Utah, USA. The locations in SLP are shrubland areas, whereas that in Utah is a coniferous forest. The diverse mountainous environments observed during the experiments were classified into five reference propagation scenarios. For each reference scenario the empirical channel envelope distribution was computed and compared with previously-published theoretical models based on the Rice, Nakagami, Weibull, and Gamma distributions. The Rice model provided the best fitting in 72.3% of the analyzed cases, whereas the Nakagami, Weibull and Gamma distributions were the best option in the remaining 11.3%, 14.9% and 1.3%, respectively. Likewise, the empirical distributions of the instantaneous mean Doppler shift (IMDS) and instantaneous Doppler spread (IDS) were computed. The results show that the IMDS follows the Generalized Extreme Value and Logistic distributions, whereas the Birnbaum-Saunders, Exponential, Burr and Nakagami distributions are proper models for the IDS. Our analysis also shows that the line-of-sight (LOS) path is the dominant factor for V2V communication in mountainous terrain, especially in roads surrounded by rocky structures with sparse vegetation. However, the contribution of non-LOS paths is not negligible, and it appears capable of supporting short intervals of communication. The results presented here can be used as guidelines for the analytical modeling and computer simulation of small-scale V2V channels in mountainous environments.

Statistical Simulation of Characteristics of an Optical Communication Channel Based on Scattered Radiation with an Unmanned Aerial Vehicle

Statistical Simulation of Characteristics of an Optical Communication Channel Based on Scattered Radiation with an Unmanned Aerial Vehicle

Method of 128-position quadrature amplitude-polarization manipulation

The functioning of modern digital communication systems tends to occur in a complex interference environment. The communication system is affected by various types of jamming: both natural noises associated with the conditions of radio waves propagation, and artificial interference concerned with electromagnetic compatibility of radio equipment, characteristics of communication channels, etc. Applied issues of enhancing digital communication systems interference insusceptibility are quite relevant at the present time. Concurrently, it is advisable to achieve an increase in interference insusceptibility by rational methods that do not require a significant increase in the emitted signals energy. The techniques based on the use of algorithms for processing special types of signals are the most promising to this date. Radio specialists address the methods for digital processing of polarization-manipulated signals which, while maintaining the communication system carrying capacity, allow us to obtain an essential gain in the parameters of the communication system interference insusceptibility. At the same time, a successful combination of these methods with the already known techniques of digital signal processing is noted. This article considers the multi-position method of quadrature amplitude-polarization manipulation (M-QAPM), where the number of positions M = 27 = 128 (128-QAPM). The modulation symbol at 128-QAPM consists of a 7-bit digital code. The purpose of this article is to describe analytically the method of 128-position quadrature amplitude-polarization manipulation when transmitting 7-bit binary modulation symbols over a communication channel. During mathematical modeling, a signal constellation was formed and visualized. The structural diagram of the modulator was given. The practical significance of the given paper lies in the fact that quadrature amplitude-polarization manipulation can be considered as a universal type of digital modulation, which can be applied instead of the currently known quadrature types of manipulation.

Channel Characterization for RIS-Aided Terahertz Communications: A Stochastic Approach

In this letter, we propose new channel characterizations for <xref ref-type="disp-formula" rid="deqn1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(1)</xref> stochastic Terahertz (THz) communications and <xref ref-type="disp-formula" rid="deqn2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(2)</xref> reconfigurable intelligent surface (RIS)-aided THz systems. Considering a spherical network with stochastic distances between nodes, we derive the exact closed-form expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the signal-to-noise ratio (SNR) over the direct link. Using the method of moments, the cascaded channels can be precisely characterized by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> distribution. We show that by using a massive number of reflecting elements, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${M}$ </tex-math></inline-formula> , (e.g., <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${M}~\geq $ </tex-math></inline-formula> 4096) the cascaded link actually outperforms the direct THz link in terms of outage probability (OP).

Measurement Based Non-Line-of-Sight Vehicular Visible Light Communication Channel Characterization

Vehicular visible light communication (V-VLC) aims to provide secure complementary vehicle-to-everything-communications (V2X) to increase road safety and traffic efficiency. V-VLC provides directional transmissions, mainly enabling line-of-sight (LoS) communications. However, reflections due to nearby objects enable non-line-of-sight (NLoS) transmissions, extending the usage scenarios beyond LoS. In this paper, we propose wide-band measurement based NLoS channel characterization, and evaluate the performance of direct current biased optical orthogonal frequency division multiplexing (DCO-OFDM) V-VLC scheme for NLoS channel. We propose a distance based NLoS V-VLC channel path loss model considering reflection surface characteristics and NLoS V-VLC channel impulse response (CIR) incorporating the temporal broadening effect due to vehicle reflections through weighted double gamma function. The proposed path loss model yields higher accuracy up to 14 dB when compared to single order reflection model whereas CIR model estimates the full width at half maximum up to 2 ns accuracy. We further demonstrate that the target bit-error-rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$10^{-3}$</tex-math></inline-formula> can be achieved up to 7.86 m, 9.79 m, and 17.62 m distances for black, orange and white vehicle reflection induced measured NLoS V-VLC channels for DCO-OFDM transmissions.