High-speed Wireless Connectivity Research Articles

Analyze the impact of nonlinear distortions on OFDM-based visible light communication systems

Visible light communication (VLC) has gained attraction for its use in high-speed wireless connectivity leveraging LED lighting elements. Orthogonal Frequency Division Multiplexing (OFDM) is an attractive modulation scheme due to its spectral efficiency and resilience to multipath distortion. However, the nonlinear electro-optic transfer characteristics of optical components introduce signal clipping and quantization noise which corrupt OFDM signals. This paper provides an in-depth analysis of clipping and quantization noise to quantify the impact of LED nonlinearities on OFDM-based VLC system performance. Detailed mathematical models are derived for clipping distortions caused by LED optical power saturation and quantization errors from ADC/DAC finite precision in the modulator and driver circuitry. This analysis is quantified through simulations of the degradations in terms of error vector magnitude (EVM), signal-to-noise ratio (SNR) loss, and bit error rate (BER) under varying clipping ratios and quantization bit-depths. The 16-QAM OFDM transmission shows that the LED driver should possess at least 12 dB signal linear dynamic range and 3-bit quantization to restrict SNR penalty within 3 dB. Adaptive tone mapping and digital pre-distortion techniques are examined to compensate for intensity distortions enabling high-speed OFDM transmission over VLC links.

Optimal channel selection for tri-band Wi-Fi in a residential scenario

The growing use of Internet of Things devices and the increasing demand for high-speed, reliable, and secure wireless connectivity pose significant challenges for existing wireless networking solutions in modern smart homes. As such, there is an increasing urgency for the development of advanced and effective wireless technologies that can fulfil the new requirements for interconnected devices and services deployed in households. Tri-band Wi-Fi 6E equipment addresses these needs by reducing the network congestion and enhancing the performance across the 2.4 GHz, 5 GHz, and 6 GHz bands. However, improper band management can lead to frequent interference and network issues. As such, this work introduces a dynamic Wi-Fi link orchestration solution that follows a heuristic model. This approach aims to optimize the network layout and channel allocation based on device metrics, utilizing the EasyMesh specification for simplified network setup and management. The model was implemented and tested in a residential environment network, using EasyMesh and tri-band Wi-Fi 6E devices. Results show the effectiveness of the model in improving network capacity and adapting the links to the current traffic, outperforming the initial and base network configuration.

Vehicle to Vehicle Communication Using Li-Fi Technology

Abstract: Vehicle-to-vehicle (V2V) communication has emerged as a pivotal technology in the automotive industry, enabling enhanced safety, efficiency, and convenience on the roads. This abstract explores the integration of Light Fidelity (LiFi) technology in V2V communication systems. LiFi, utilizing visible light communication (VLC), offers high-speed wireless connectivity by using light-emitting diodes (LEDs) to transmit data. By harnessing LiFi's unique advantages such as increased bandwidth, low latency, and immunity to radio frequency interference, V2V communication systems can facilitate real-time exchange of critical information between vehicles, including traffic conditions, collision warnings, and cooperative driving maneuvers. This paper delves into the technical aspects, challenges, and potential applications of LiFi-enabled V2V communication, shedding light on its promising role in revolutionizing the future of smart and connected transportation systems

Research and building a voice-controlled environmental mornitoring device using internet of things

The article focuses on researching, designing and building a device that functions as a robot that can be controlled automatically through voice on a virtual assistant from the user. Products with inherited features and apply the positive advantages of commercially available devices on the market, applying technologies of the 4.0 revolution such as: artificial intelligence, Internet of Things, high-speed wireless connection, etc. The product is capable of understanding pre-programmed commands and performing tasks when users give voice commands such as measuring temperature, humidity, and ambient air quality. The product is especially useful for collecting environmental information in places and areas with dangerous conditions that are difficult for humans to access such as deep mines, polluted air, and mine traps, etc. Experimental results indicate that the device works well, is flexible, able to collect accurate information and can be used in practice.

A Testbed for Investigating the Effect of Salinity and Turbidity in the Red Sea on White-LED-Based Underwater Wireless Communication

Several industrial and scientific underwater applications require high-speed wireless connectivity. Acoustic communications have low data rates and high latency, whereas attenuation in seawater severely limits radio frequency communications. Optical wireless communication is a promising solution, with high transmission rates (up to Gb/s) and little attenuation in water at visible wavelengths. This study explores the feasibility of white-LED-based underwater optical wireless communication (UWOC) by considering Red Sea parameters. High salinity is the most prominent attribute of the Red Sea that can affect underwater communication and requires investigation. Considering this, the received signal intensity fluctuation under increasing water salinity was experimentally investigated. In the same experiment, the impact of growing turbidity was tested, as it is the most influential parameter and tends to block the entire LED-based communication system with little increase. The experimental results show that the signals are affected less by salinity and more by turbidity but are found to be sufficiently strong to be used for communication in the Red Sea. Finally, it was concluded that a white LED is capable of sending data at the maximum possible salinity values of 40 g/L. However, the turbidity can significantly limit the transmission distance to less than 60 cm.

An Optimisation driven Deep Residual Network for Sybil attack detection with reputation and trust-based misbehaviour detection in VANET

ABSTRACT Vehicular Ad hoc Network (VANET) has recently gained significant attention as a means of enhancing the mobility, efficiency, and safety of applications in the intelligent transportation system. However, because of its high-speed mobility, wireless connectivity, and extensive node coverage, security is a more difficult procedure. The Sybil security threat on VANET is a growing problem today. The Road Side Unit (RSU) failed to synchronise its clock with the legal vehicle, then unplanned vehicles are predicted, thereby incorrect messages are transferred to them. In this paper, Competitive Dolphin Echolocation Optimisation (CDEO)-based Deep Residual Network is proposed for Sybil attack and RSU misbehaviour detection. Here, the effective routing process is performed using Fractional Glow-Worm Swarm Optimisation (FGWSO)-based traffic-aware routing protocol. In the base station, the Sybil attack detection is done. The Sybil attack detection process is done using a Deep residual network, which is trained by the proposed CDEO algorithm. The CDEO algorithm is devised by incorporating Dolphin Echolocation Optimisation (DEO) technique and Competitive Swarm Optimiser (CSO). Additionally, using the Deep residual network, the RSU misbehaviour detection is done. The performance of the developed method is compared with certain performance metrics, like precision, F1-measure, and recall of 0.9197, 0.9121, and 0.9046.

Experimental demonstration of an indoor optical wireless communication system with a waveform index modulated uplink.

The optical wireless communication (OWC) technology has been widely studied to provide high-speed wireless connections in indoor environments. Compared with the downlink, the uplink faces more restrictions, such as the stringent power, complexity, and cost requirements. In this Letter, we propose a waveform index modulated OWC uplink with each waveform seen as a virtual transmitter. Extra data is transmitted via the index of selectively activated virtual transmitter, and the OWC uplink speed can be improved whilst achieving similar bit-error-rate (BER) performance. The waveform index modulated uplink is experimentally demonstrated in a near-infrared OWC system. Results show that up to 15 Gb/s data rate is achieved with the proposed waveform index modulated uplink, which increases the data rate significantly with similar power and BER.

Online Notice Board System

Digital Notice Board is most important factor in any organization or public utility for the places like bus stop, railway stations, schools, colleges, malls, etc. But sticking multiple notices every day is a irritating process. An person character is wanted to take care of these notices. This mission is about advanced cell board. The task is built around raspberry-pi. Display is obtained on LCD. A wi-fi continuously used for Data transmission. We can add or erase or differ the textual content material in accordance to our need. At transmitter, authorized PC is used for sending notices. At receiving end wi-fi fidelity is linked to raspberry pi. When a licensed consumer sends a message that is to be displayed from his system, it is familiar via way of receiver. Wireless is a popular technology known- that how to approve digital device to alternate information over a pc network, collectively with high speed wireless connections. The data is acquired from authenticated user, then it sends the archives to raspberry pi.

On the beamforming design of millimeter wave UAV networks: Power vs. capacity trade-offs

The millimeter wave (mmWave) technology enables unmanned aerial vehicles (UAVs) to offer broadband high-speed wireless connectivity in 5G/6G networks. However, the limited footprint of a single UAV implementing analog beamforming (ABF) requires multiple aerial stations to operate in swarms to provide ubiquitous network coverage, thereby posing serious constraints in terms of battery power consumption. A possible remedy is to investigate the concept of hybrid beamforming (HBF) transceivers, which use a combination of analog beamformers to achieve higher flexibility in the beamforming design. This approach permits multiple ground users to be served simultaneously by the same UAV, despite involving higher energy consumption than its ABF counterpart. This paper presents a tractable stochastic analysis to characterize the ergodic capacity and power consumption of UAV mmWave networks, focusing on the trade-off between ABF and HBF architectures. A multi-beam coverage model is derived as a function of several UAV-specific parameters, including the number of UAVs, the deployment altitude, the antenna configuration, and the beamforming design. Our results show that, while ABF achieves better ergodic capacity at high altitudes, an HBF configuration with multiple beams, despite the use of more individually power-hungry RF blocks, always consumes less total power with limited capacity degradation.

Conformal Transmitarrays for Unmanned Aerial Vehicles Aided 6G Networks

Unmanned aerial vehicles (UAVs) aided wireless communications promise to provide high-speed cost-effective wireless connectivity without needing fixed infrastructure coverage. They are a key technology enabler for sixth generation (6G) wireless networks, where a three-dimensional coverage including space, aero and terrestrial networks are to be deployed to guarantee seamless service continuity and reliability. Owing to the aerodynamic requirements, it is highly desirable to employ conformal antennas that can follow the shapes of the UAVs to reduce the extra drag and fuel consumption. To enable hundred giga-bits-per-second (Gb/s) data rates and massive connectivity for 6G networks, conformal antenna arrays featured with high gains and beam scanning/multiple beams are demanded for millimeter-wave and higher-frequency-range communications. However, new challenges exist in designing and implementing high-gain conformal arrays for UAV platforms. In this article, we overview the recent advances in conformal transmitarrays for UAV-based wireless communications, introducing new design methodologies and high-lighting new opportunities to be exploited.

Collective Intelligence Using 5G: Concepts, Applications, and Challenges in Sociotechnical Environments

Distributed intelligence is a well-known approach for optimizing interactions among numerous smart devices that interconnect and operate together as Internet of Things (IoT) systems. A modern form of human-machine <i>collective intelligence</i> emerges when humans interact with IoT systems in sociotechnical environments such as smart homes. Fifth-generation (5G) communication networks are designed for high-speed reliable wireless connectivity and expected to boost IoT and (distributed) collective intelligence by revolutionizing human&#x2013;device&#x2013;human interactions. In this paper, we contribute a comprehensive review of state-of-the-art sociotechnical environments that exhibit collective intelligence, supported by 5G-enabled IoT. We discuss the latest developments in 5G and their implications for collective intelligence. Further, we explain the key challenges for using 5G to support collective intelligence, e.g., data processing, security, and radio resource management. Finally, we describe four practical applications of collective intelligence to sociotechnical environments&#x2014;road traffic control, unmanned aerial vehicles, electrical load demand response, and augmented democracy.

A Review on LiFi Network Research: Open Issues, Applications and Future Directions

This paper extensively reviews and analyses Light Fidelity (LiFi), a new technology that uses light to transmit data as a high-speed wireless connection system from a wide spectrum of domains. An in-depth analysis and classifications of pertinent research areas for LiFi networks are presented in this paper. The various aspects constituting this paper include a detailed literature review, proposed classifications, and statistics, which further is deliberated to encompass applications, system architecture, system components, advantages, and disadvantages. LiFi and other technologies are compared, multi-user access techniques used in LiFi networks are investigated and open issues are addressed in detail. The paper is concluded with a comprehensive taxonomy of literature comparison that has served as the basis of the proposed open issues and research trends.

An energy-efficient recovery algorithm for the free space optical communications network via reflections

Free space optical (FSO) communication is a very attractive solution to substitute or complement radio frequency-based wireless technologies for providing high-speed wireless connections. FSO-based network consists of a lot of optical nodes, whose transmission power is concentrated in a narrow volume. Considering the directionality of FSO communications, the outage of a node in the network may result in reduced link connectivity and availability, thus causing coverage hole. Once the coverage hole, the accuracy of network monitoring data would not only be reduced, but much of the not-yet-used resource would also be abandoned in the network resulting in energy waste. In this paper, we propose an energy-efficient recovery algorithm for FSO network based on reflections. The proposed algorithm adopts the classified repair mode based on the communication conditions prior to dying of the node. If the dead node is a relay node, the mirror node is used as the repair node in order to reduce the energy consumption of data forwarding, and an evaluation model is established by combining the coverage and the energy to determine the repair location. However, if the dead node is not a relay node, the ordinary node is used as repair node. The location of the repair node is found based on the coverage and the geometric relationship to ensure the maximum coverage. The simulation results show that, the proposed algorithm not only sustains coverage but also reduces the network energy consumption and prolongs the network's lifetime.

Electromagnetically Aware Design of Capacitive Touch Sensor Panel Electrodes for Antenna Integration

Modern electronic devices increasingly rely on efficient antenna integration strategies for supporting high-speed wireless connectivity. Especially for bezel-less displays, these antennas are generally placed underneath the touch sensor panel (TSP) where they interact strongly with the sensing electrodes. To overcome this problem, we engineer the shapes of these electrodes to facilitate the transmission of electromagnetic waves having frequency identical to the operating frequency of the integrated antenna. We thereby propose a new design methodology for TSP electrodes and demonstrate its advantages with respect to antenna integration. As an example, we present the design of a TSP that has a pass-band at 2.51GHz and 5.66GHz for TE polarization and 3.01GHz for TM polarization. We integrate a printed dipole antenna with the proposed as well as a standard TSP geometry, placing it right underneath rather than beside the panel. Comparing the radiation patterns at 2.5GHz, we show that the pattern is significantly different than its free-space one, when a standard TSP geometry is used. Yet, the proposed one leads to a pattern that is almost identical (improved by 3.93dB as compared to standard TSP) to that in free-space.

Max-Min Fair Resource Allocation in Millimetre-Wave Backhauls

5G mobile networks are expected to provide pervasive high speed wireless connectivity and support increasingly resource intensive user applications. Network hyper-densification therefore becomes necessary, though connecting to the Internet tens of thousands of base stations is non-trivial, especially in urban scenarios where optical fibre is difficult and costly to deploy. The millimetre wave (mm-wave) spectrum is a promising candidate for inexpensive multi-Gbps wireless backhauling, but exploiting this band for effective multi-hop data communications is challenging. In particular, resource allocation and scheduling of very narrow transmission/ reception beams require to overcome terminal deafness and link blockage problems, while managing fairness issues that arise when flows encounter dissimilar competition and traverse different numbers of links with heterogeneous quality. In this paper, we propose WiHaul, an airtime allocation and scheduling mechanism that overcomes these challenges specific to multi-hop mm-wave networks, guarantees max-min fairness among traffic flows, and ensures the overall available backhaul resources are fully utilised. We evaluate the proposed WiHaul scheme over a broad range of practical network conditions, and demonstrate up to 5× individual throughput gains and a five-fold improvement in terms of measurable fairness, over recent mm-wave scheduling solutions.

Orthogonal Frequency Division Multiplexing Techniques Comparison for Underwater Optical Wireless Communication Systems.

Optical wireless communication is an energy-efficient and cost-effective solution for high-speed and highly-secure wireless connections. In this paper, we compare, discuss, and analyze three popular optical orthogonal frequency division multiplexing (OFDM) techniques, such as DC-biased optical OFDM (DCO-OFDM), asymmetrically-clipped optical OFDM (ACO-OFDM), and unipolar OFDM (U-OFDM), for underwater optical wireless communication systems. The peak power constraint, bandwidth limit of the light source, turbulence fading underwater channel, and the channel estimation error are taken into account. To maximize the achievable data propagation distance, we propose to optimize the modulation index that controls the signal magnitude, and a bitloading algorithm is applied. This optimization process trades off the clipping distortion caused by the peak power constraint and the signal to noise ratio (SNR). The SNR and clipping effects of the three compared OFDM techniques are modeled in this paper. From the numerical results, DCO-OFDM outperforms ACO- and U-OFDM when the transmitted bit rate is high compared to the channel bandwidth. Otherwise, U-OFDM can provide a longer propagation distance or requires less transmitted power.

Variable Pulse Width Unipolar Orthogonal Frequency Division Multiplexing for Visible Light Communication Systems

Visible light communication (VLC) systems working as high-speed and short-range wireless connection methods have attracted more and more attention. This paper proposes a variable pulse width unipolar optical orthogonal frequency-division multiplexing (VPW-OFDM) scheme for indoor VLC systems. Similar to the polar-based optical OFDM, Hermitian symmetric data are not required to generate real signals. Instead, the magnitude and phase components of the complex-valued OFDM signal are transmitted successively. Unlike the polar-based optical OFDM, the proposed VPW-OFDM allows using variant pulse widths to reduce the effects of the noise added on the phase component. By adaptively optimizing the pulse widths, the proposed VPW-OFDM outperforms the polar-based OFDM and other state-of-the-art optical OFDM techniques, such as dc-biased optical OFDM, asymmetrically clipped optical OFDM, and unipolar-OFDM. For indoor VLC systems, illumination requirement is crucial and needs to be considered. In this paper, we analyze the effects of the illumination requirements on system performance. Bit error rate and transmitted bit rate are used as criteria to evaluate the communication performances for the techniques tested. In addition, the system channel with bandwidth limitation is taken into account. To enhance the data throughput, a single-tap equalizer at the receiver and the bit loading algorithm are applied. From the numerical results, the proposed VPW-OFDM outperforms DCO-, ACO-, U-, and polar-based OFDM for a wide channel bandwidth.

Bidirectional Relaying MMW Radio over Plastic Optical Fiber Systems in Home Area Networks

In this paper, we propose a novel home area networks (HAN) architecture using MMW radio-over-plastic optical fiber (MMW/RoPOF) to provide high-speed wireless connections to end users. The proposed HAN can support bidirectional half-duplex communication between any pair of mobile stations (MSs) thanks to the use of analog network coding in optical domain implemented at a center station (CS). We analyze the performance of an end-to-end communication link between two MSs under the impact of major physical impairments originated from both fiber and wireless links. The numerical results in terms of bit error rate (BER) and normalized throughput demonstrate that it is feasible to deploy MMW/RoPOF in HAN. In addition, useful information for the design of HAN can be obtained from this paper.

Analysis of Effective Capacity and Throughput of Polling-Based Device-To-Device Networks

Next-generation wireless networks will give rise to heterogeneous networks by integrating multiple wireless access technologies to provide seamless mobility to mobile users with high-speed wireless connectivity. Device-to-device (D2D) communication has proven to be a promising technology that can increase the capacity and coverage of wireless networks. The D2D communication was first introduced in long-term evolution advanced (LTE-A) and has gained immense popularity for the offloading traffic using the licensed and unlicensed band. Challenges arise from resource allocation, provision of quality-of-service (QoS), and the quantification of capacity in an unlicensed band due to the distributed nature of Wi-Fi. In this paper, we propose an analytical performance model for the scalable MAC protocol (SC-MP) in which a resource allocation mechanism is based on the IEEE 802.11 point coordinated function to access the Wi-Fi channel for voice and video/multimedia traffic. In the SC-MP, D2D communication is applied to further offload the video/multimedia traffic. In particular, this paper establishes a three-state semi-Markovian model to derive a closed-form expression of effective capacity in terms of transmission rate and quality-of-service. Further, the SC-MP is analytically modeled using the four-state traditional Markov model to derive the saturation throughput. The analytical results are validated through simulations, hence, proving the appropriateness of the model.

High-speed indoor optical wireless communication system employing a silicon integrated photonic circuit.

Beam-steering-based optical wireless technologies are being widely investigated due to the capability of providing high-speed wireless connectivity in indoor applications. However, high-speed indoor optical wireless systems are traditionally realized with discrete bulky components, significantly limiting their practical applications. In this Letter, we demonstrate an infrared optical wireless communication system employing a miniaturized silicon integrated photonic circuit for beam steering for the first time. Experimental results show that up to 12.5Gb/s optical wireless communication can be achieved with error-free performance over a free-space range of 140cm, and limited mobility of users can be realized. The experimental results of this Letter open the way for realizing integrated high-speed optical wireless communications.