Data Rate Applications Research Articles

Leveraging Intermolecular Charge Transfer for High-Speed Optical Wireless Communication.

Intermolecular charge transfer (CT) complexes have emerged as versatile platforms with customizable optical properties that play a pivotal role in achieving tunable photoresponsive materials. In this study, we introduce an innovative approach for enhancing the modulation bandwidth and net data rates in optical wireless communications (OWCs) by manipulating combinations of monomeric molecules within intermolecular CT complexes. Concurrently, we extensively investigate the intermolecular charge transfer mechanism through diverse steady-state and ultrafast time-resolved spectral techniques in the mid-infrared range complemented by theoretical calculations using density functional theory. These intermolecular CT complexes empower precise control over the -3 dB bandwidth and net data rates in OWC applications. The resulting color converters exhibit promising performance, achieving a net data rate of ∼100 Mb/s, outperforming conventional materials commonly used in the manufacture of OWC devices. This research underscores the substantial potential of engineering intermolecular charge transfer complexes as an ongoing progression and commercialization within the OWC. This carries profound implications for future initiatives in high-speed and secure data transmission, paving the way for promising endeavors in this area.

BeSleep: Blockchain‐enabled distributed sleeping strategies of small base stations in ultra dense networks

SummarySmall cell networks can fulfill the increasing demandfor the high data rate of wireless applications. Energy efficiency is an important design parameter of the ultra dense small cell network (UDSCN). The sleeping strategy of small base stations (s‐BSs) is used to enhance the network's energy efficiency. An efficient sleeping strategy of s‐BSs is required while preserving users' quality of service (QoS). The idle s‐BSs can be switched to sleep mode. This paper proposes a blockchain‐enabled solution for the sleeping strategy of s‐BSs. Here, a blockchain‐enabled small cell network is created between the s‐BSs. The network is decentralized, which eliminates the workload of the macro base station (MBS). The proposed network architecture is enabled as a decentralized network through blockchain. The blockchain provides distributed control over the s‐BS operations through a smart contract. Here, smart contracts act as distributed self organizing network features to handle self‐transactions among small cells for switching off s‐BSs in the network. All the software logic required to perform s‐BS operations is written in a smart contract using Ethereum. The proposed solution improves energy efficiency and enables the ultra dense small cell network to be decentralized.

An Improved Wavelength Diversity Based Free Space Optical Link: Effects of Fog and Atmospheric Turbulence

Free-space optical (FSO) communication systems have received a lot of attention from academia and industries due to their low cost, high security and data rates for various wireless communication applications. However, factors such as fog and atmospheric turbulence degrade the performance of the FSO communication system. Therefore, this study presents an improved wavelength diversity based free space optical link using a single channel approach. The authors employed both Kim and Al-Naboulsi’s models to model the attenuation-induced FSO link. Furthermore, the Gamma-Gamma turbulent model was utilized to explain the turbulent nature of the FSO communication link. Experimental results showed improved performance in terms of Bit Error Rate (BER) and Quality factor of the FSO link up to a distance of 7km compared to the multiple channel approach that gives a signal output for distances less than 3km only. Hence, the impact of attenuation on the FSO link was reduced and the performance of the system was enhanced under fog and atmospheric turbulence conditions.

Optimization of strip-based hybrid plasmonic terahertz waveguide with distributed Bragg reflector layers

In view of recent developments in the utilization of terahertz (THz) communications technology for the increasing demands of high speed and data rates for various wireless applications, this research work targets the design and analysis of distributed Bragg reflector (DBR)-based hybrid plasmonic THz waveguide. This THz waveguide operates at a frequency range from 2.5 to 3.5 THz. The proposed DBR-based hybrid plasmonic THz waveguide consists of DBR layers of gallium arsenide (GaAs) and aluminum arsenide, high-density polyethylene (HDPE) as substrate, a GaAs stripe for wave-guidance, and few layers of graphene layers in HDPE for better confinement. To increase the light confinement between DBR and graphene, a GaAs strip is placed into HDPE. By altering the width and height of the GaAs strip, the parameters birefringence, mode field diameter (MFD), confinement loss, effective mode area, beat length, and dispersion have been fully examined. The obtained simulation results shows high birefringence of 0.6276, maximum MFD of 45 mm, low confinement loss of 7.5 × 10 − 9 mm − 1, high effective mode area of 16.5 mm2, and low anomalous dispersion of 0.0023 (ps/THz/cm) in the range of 2.5 to 3.5 THz. This optimized THz waveguide may helps to enable in guided THz applications for photonic integrated circuits.

Genetic Algorithm for Optimizing Energy Efficiency in Downlink mmWave NOMA System with Imperfect CSI

Nonorthogonal multiple access (NOMA) is considered a promising technique for improving energy efficiency (EE) in beyond-5G wireless systems. In this paper, we investigate the maximization of EE of downlink wireless systems by combining mmWave with NOMA technologies, considering the asymmetric required data rate of user applications. We propose a genetic algorithm (GA) to solve the non-convex energy efficiency problem for an imperfect CSI downlink mmWave NOMA system. The studied mixed-integer optimization problem was converted to an integer optimization problem and solved using a GA, which determines the best clustering members in mmWave NOMA. The required population size of the proposed GA was determined to evaluate its effectiveness for a massive number of users. In addition, the GA’s convergence to the optimal solution for light traffic and relatively heavy traffic was also analyzed. Our results illustrate that the solution obtained solution via GA is almost equal to the optimal value and outperforms the conventional orthogonal multiple access, where the EE is improved by more than 75%. Finally, the impact of the estimation error of CSI on the system performance was evaluated at different required SINR scenarios. The results show that EE is degraded in the case of imperfect CSI case but is still close to the optimal solution.

Channel Measurements and Modeling for Low Terahertz Communications in an Aircraft Cabin

The low terahertz band (0.1–1 THz) offers very high data rates for novel mobile applications and constitutes a promising candidate to meet the requirements in aviation, enabling future wireless in-flight entertainment (IFE) systems. An extensive knowledge of the propagation effects in the radio channel in complex scenarios is a prerequisite to successfully design a communication system. This article presents a measurement campaign in a real aircraft investigating the radio channel at 300 GHz for different deployments of a wireless IFE system. The propagation effects as well as temporal and spatial channel characteristics are analyzed for likely communication links between an access point and a user equipment (UE). In the same way, interference links between two UEs are studied, reporting transmission and reflection losses for various components of the aircraft. A deterministic and geometry-based channel model is derived and extended to cover the effect of human blockage that suggests an integration of the access point into the passenger service unit. The measurement and realistic path loss models can be used in further link and system level simulations and contribute to the design of future IFE systems.

A 164-$\mu$ W 915-MHz Sub-Sampling Phase-Tracking Zero-IF Receiver With 5-Mb/s Data Rate for Short-Range Applications

This article presents a 915-MHz ultra-low-power (ULP) sub-sampling phase-tracking receiver (SSPT-RX). It is targeted for the power-constrained devices that need short range but medium high-speed data receiving, such as the multi-channel neural stimulator with arbitrary waveform generation. The zero-intermediate frequency (zero-IF) phase-tracking receiver (PT-RX) topology is adopted to simplify the sub-sampling RX architecture with direct demodulation of frequency-shift keying (FSK) signal while improving the image frequency issue. The frequency of local oscillator (LO) is reduced by ten times with the proposed architecture, which leads to greatly reduced power consumption. Fabricated in 65-nm CMOS process, the RX chip occupies an active area of 0.58 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The RX consumes one of the lowest power consumptions of 164 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> from 0.5-/1-V supplies. It achieves an energy efficiency of 32.8 pJ/bit at a data rate of 5 Mb/s, which is improved by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 5.6\times $ </tex-math></inline-formula> compared to the state-of-the-art RXs. The measured sensitivity of 915-MHz FSK signal receiving is −69.5 dBm with an LO frequency of 91.5 MHz, which is 1/10 of the carrier frequency. The achieved RX sensitivity figure-of-merit (FoM) is 174.3 dB.

URadio: Wideband Ultrasound Communication for Smart Home Applications

Smart home Internet of Things (IoT) has a vibrant market with a wide range of appliances and sensors, spanning across smart home, smart city, and smart factory. However, the security and privacy of these IoT systems have raised serious concerns. Currently, most IoT devices rely on electromagnetic wave-based radio frequency (RF) for communication. Yet, RF has several inherent limitations, such as shortage of spectrum, susceptible to interference, and vulnerable to eavesdropping or jamming attacks. This article presents URadio, a wideband ultrasonic communication system. By leveraging recent advances in reduced Graphene Oxide (rGO), we design a new type of electrostatic ultrasonic transducer, which can achieve more than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6\times $ </tex-math></inline-formula> bandwidth than commercial ultrasonic transducers. With this new transducer, we design an OFDM communication system to maximize its data rate for smart home applications. We build a prototype of URadio on a wireless testbed and evaluate its performance in several real-world environments. Our experiments show that URadio can reach up to 360 kb/s data rate at a distance of 81 cm or 20 Kb/s data rate at a distance of 20 m, which supports a variety of smart home applications. We further showcase URadio’s resilience against eavesdropping and jamming attacks, as well as demonstrate its capability of securely localizing objects in an indoor environment.

Enhanced 850-nm SM VCSEL transmission by favorable chirp interaction with fiber dispersion

Single-mode (SM) vertical-cavity surface-emitting lasers (VCSELs), especially those operating around 850 nm, have been studied intensively in recent years for short distance transmission. Despite the demonstrations of increased data rate and system distance, the impact of frequency chirp that is commonly present in directly modulated lasers is an area that needs more detailed studies for 850 nm VCSEL-based systems. In this paper, we explore the interaction between a laser chirp and fiber chromatic dispersion using an 850-nm SM VCSEL over a standard SM fiber that is two-mode at the operating wavelength. Our transmission experiments show that the system can enjoy a benefit from negative fiber dispersion instead of a penalty compared to the back-to-back case, due to the favorable chirp–dispersion interaction, which is also supported by our system bandwidth measurements. Furthermore, we measure the chirp value of the SM VCSEL and conduct modeling using the time-domain pulse concept to illustrate the impact on the chirp–dispersion interaction and explore the optimal chirp parameters for different transmission data rates. Our study indicates a significant system benefit of using 850-nm SM VCSELs with a high bandwidth single-mode fiber around 850 nm due to the favorable chirp–dispersion interaction. Such a benefit can enable high data rate and longer distance system transmission for modern data center applications.

Reconfigurable 2×1 CPW-Fed Rectangular Slot Antenna Array (RSAA) Based on Graphene for Wireless Communications

This article presents a 2×1 CPW ultra wideband rectangular slot antenna array (UWB-RSAA) with a modified circular slot shape to support a high data rate for wireless communications applications. The proposed antenna array dimensions are 0.7λ×0.8λo×0.064λo at the resonant frequency 1.8 GHz. It is fabricated on Rogers RO4003 substrate and fed by using a coplanar waveguide (CPW). A graphene layer is added on one side of the substrate to realize frequency reconfigurability and improve the array gain. The proposed array acquires -10 dB impedance bandwidth of the RSAA that extends from 1.7 GHz to 2.6 GHz, from 3.2 to 3.8 GHz, and from 5.2 GHz to 7 GHz. The proposed array achieved a realized peak gain of 7.5 dBi at 6.5 GHz at 0 Volt bias with an average gain of 4.5 dBi over the operating band. When the graphene bias is increased to 20 Volt, the antenna bandwidth extends from 1 GHz to 4 GHz and from 5 to 7 GHz with a peak gain of 14 dBi at 3.5 GHz and an average gain of 7.5 dBi. The linearly polarized operation of the proposed array over the operating bands makes it suitable for short-range wireless communications .

A Systematic Investigation of Blocking Strategies for Real-Time Classification of Social Media Content into Events

Events play a prominent role in our lives, such that many social media documents describe or are related to some event. Organizing social media documents with respect to events thus seems a promising approach to better manage and organize the ever-increasing amount of user-generated content in social media applications. It would support the navigation of data by events or allow one to get notified about new postings related to the events one is interested in, just to name two applications. A challenge is to automatize this process so that incoming documents can be assigned to their corresponding event without any user intervention. We present a system that is able to classify a stream of social media data into a growing and evolving set of events. In order to scale up to the data sizes and data rates in social media applications, the use of a candidate retrieval or blocking step is crucial to reduce the number of events that are considered as potential candidates to which the incoming data point could belong to.In this paper we present and experimentally compare different blocking strategies along their cost vs. effectiveness tradeoff.We show that using a blocking strategy that selects the 60 closest events with respect to upload time, we reach F-Measures of about 85.1% while being able to process the incoming documents within 32ms on average. We thus provide a principled approach supporting to scale up classification of social media documents into events and to process the incoming stream of documents in real time.

Cell-Free Massive MIMO-OFDM Transmission Over Frequency-Selective Fading Channels

This letter presents and analyzes orthogonal frequency-division multiplexing (OFDM)-based multi-carrier transmission for cell-free massive multi-input multi-output (CFmMIMO) over frequency-selective fading channels. Frequency-domain conjugate beamforming, pilot assignment, and user-specific resource allocation are proposed. CFmMIMO-OFDM is scalable to serve a massive number of users and is flexible to offer diverse data rates for heterogeneous applications.

High-Speed Millimeter-Wave Mobile Experimentation on Software-Defined Radios

Millimeter-wave (mm-Wave) communications have become an integral part of WLAN standards and 5G mobile networks and, as application data rate requirements increase, more and more traffic will move to these very high frequency bands. Although there is an ample choice of powerful experimental platforms for sub-6 GHz research, building mm-Wave systems is much more difficult due to the very high hardware requirements. To address the lack of suitable experimentation platforms, we propose mm-FLEX, a flexible and modular open platform with real-time signal processing capabilities that supports a bandwidth of 2 GHz and is compatible with current mm-Wave standards. The platform is built around a fast FPGA processor and a 60 GHz phased antenna array at front-end that can be reconfigured at nanosecond timescales. Together with its ease of use, this turns the platform into a unique tool for research on beam training in highly mobile scenarios and full-bandwidth mm-Wave signal processing.

Effects of Transport Network Slicing on 5G Applications

Network slicing is considered a key technology in enabling the underlying 5G mobile network infrastructure to meet diverse service requirements. In this article, we demonstrate how transport network slicing accommodates the various network service requirements of Massive IoT (MIoT), Critical IoT (CIoT), and Mobile Broadband (MBB) applications. Given that most of the research conducted previously to measure 5G network slicing is done through simulations, we utilized SimTalk, an IoT application traffic emulator, to emulate large amounts of realistic traffic patterns in order to study the effects of transport network slicing on IoT and MBB applications. Furthermore, we developed several MIoT, CIoT, and MBB applications that operate sustainably on several campuses and directed both real and emulated traffic into a Programming Protocol-Independent Packet Processors (P4)-based 5G testbed. We then examined the performance in terms of throughput, packet loss, and latency. Our study indicates that applications with different traffic characteristics need different corresponding Committed Information Rate (CIR) ratios. The CIR ratio is the CIR setting for a P4 meter in physical switch hardware over the aggregated data rate of applications of the same type. A low CIR ratio adversely affects the application’s performance because P4 switches will dispatch application packets to the low-priority queue if the packet arrival rate exceeds the CIR setting for the same type of applications. In our testbed, both exemplar MBB applications required a CIR ratio of 140% to achieve, respectively, a near 100% throughput percentage with a 0.0035% loss rate and an approximate 100% throughput percentage with a 0.0017% loss rate. However, the exemplar CIoT and MIoT applications required a CIR ratio of 120% and 100%, respectively, to reach a 100% throughput percentage without any packet loss. With the proper CIR settings for the P4 meters, the proposed transport network slicing mechanism can enforce the committed rates and fulfill the latency and reliability requirements for 5G MIoT, CIoT, and MBB applications in both TCP and UDP.

Signal Properties under Multi-Carrier Chaos–Shift Keying

In recent years, increased demand for high-quality multimedia services requires increasing the wireless communications application data rates and be more reliable and secure. To meet this request, the researches related to Multi-Carrier (MC) transmission technologies have made considerable efforts in recent years because multi-carrier techniques can improve the data transmission rates. In this research, an overall study on performing Multi-Carrier Chaos Shift keying by using a technique Orthogonal Frequency Division Multiplexing (OFDM) is presented. A multi-carrier system simulation is designed because of the limited speed provided by Chaos Shift keying (CSK) due to the spreading factor. To increase security in this system; the chaotic sequence was generated by proposed to modify on one of the well-known chaos generators that is a tent map. The performance test and the security analysis were carried out using the Bit Error Rate (BER), Mean Squared Error (MSE), correlation test; the chaotic characteristics of the chaos generators sequences using are tested the Lyapunov Exponent. Results have showed the proposed tent map the autocorrelation is like a delta function, so that it appears as a noise that is difficult to discern the information carried by signal, it is much more sensitive to change the initial state and control parameters, where the proposed tent map provides better chaotic properties for encryption such as greater Lyapunov exponent, compared with well-known chaos maps (Logistic map1, Tent map, Quadratic map), it provides a lower Bit Error Rate (BER) performance than a tent map. In addition, the proposed method to multi-carrier CSK system with various Spreading Factors (SF) values outperforms the CSK system in improving the data transmission rate.

Compact cross-shaped parasitic strip based multiple-input multiple-output (MIMO) dielectric resonator antenna for ultra-wideband (UWB) applications

Abstract In this article, cross-shaped metallic parasitic strips based two radiator element multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) is excited by quadrature wave transformer microstrip feedline, designed, simulated and fabricated for ultra-wideband (UWB) applications. The proposed MIMO antenna structure is implemented with the help of two rectangular-shaped radiator elements that supports three modes HE11δ , HE21δ , and HE12δ at 4.4, 8.3, 10.8 GHz respectively. These fundamental and higher-order modes are supported to wide impedance bandwidth. Inverted T-shaped metallic strip and ground stub to improve the impedance bandwidth 104.6% (3.3–10.8 GHz) with 5.7 dBi peak gain, to enhance the coupling coefficient by stub, scissor-shaped defected ground structure and cross-shaped metallic parasitic strips are used in the existed structure. The MIMO diversity parameters are implemented as simulated ECC ≤ 0.003, DG ≥ 9.98 dB, and CCL ≤ 0.68. All the obtained MIMO antenna parameters are within the acceptable limit for providing high data rate for UWB applications.

Leveraging Sensing at the Infrastructure for mmWave Communication

V2X communication in the mmWave band is one way to achieve high data rates for applications like infotainment, cooperative perception, augmented reality assisted driving, and so on. MmWave communication relies on large antenna arrays, and configuring these arrays poses high training overhead. In this article, we motivate the use of infrastructure mounted sensors (which will be part of future smart cities) to aid establishing and maintaining mmWave vehicular communication links. We provide numerical and measurement results to demonstrate that information from these infrastructure sensors reduces the mmWave array configuration overhead. Finally, we outline future research directions to help materialize the use of infrastructure sensors for mmWave communication.

Speech Quality Classifier Model based on DBN that Considers Atmospheric Phenomena

Current implementations of 5G networks consider higher frequency range of operation than previous telecommunication networks, and it is possible to offer higher data rates for different applications. On the other hand, atmospheric phenomena could have a more negative impact on the transmission quality. Thus, the study of the transmitted signal quality at high frequencies is relevant to guaranty the user ́s quality of experience. In this research, the recommendations ITU-R P.838-3 and ITU-R P.676-11 are implemented in a network scenario, which are methodologies to estimate the signal degradations originated by rainfall and atmospheric gases, respectively. Thus, speech signals are encoded by the AMR-WB codec, transmitted and the perceptual speech quality is evaluated using the algorithm described in ITU-T Rec. P.863, mostly known as POLQA. The novelty of this work is to propose a non-intrusive speech quality classifier that considers atmospheric phenomena. This classifier is based on Deep Belief Networks (DBN) that uses Support Vector Machine (SVM) with radial basis function kernel (RBF-SVM) as classifier, to identify five predefined speech quality classes. Experimental Results show that the proposed speech quality classifier reached an accuracy between 92% and 95% for each quality class overcoming the results obtained by the sole non-intrusive standard described in ITU-T Recommendation P.563. Furthermore, subjective tests are carried out to validate the proposed classifier performance, and it reached an accuracy of 94.8%.

On the Feasibility of Multi-Mode Antennas in UWB and IoT Applications below 10 GHz

While on the one hand 5G and B5G networks are challenged by ultra-high data rates in wideband applications like 100+ Gbps wireless Internet access, on the other hand they are expected to support reliable low-latency Internet of Things (IoT) applications with ultra-high connectivity. These conflicting challenges are addressed in a system proposal dealing with both extremes. In contrast to most recent publications, focus is on the frequency domain below 10~GHz. Towards this goal, multi-mode antenna technology is used and different realizations, offering up to eight uncorrelated ports per radiator element, are studied. Possible baseband architectures tailored to multi-mode antennas are discussed, enabling different options regarding precoding and beamforming.

ESSENCE: GPU-based and dynamic key-dependent efficient stream cipher for multimedia contents

Data Confidentiality (DC) is considered one of the most important security services. Currently, a set of existing cipher algorithms is being used to ensure DC. However, researchers constantly investigate the design and implementation of more efficient cipher schemes. To this end, different versions of AES have been implemented efficiently on GPUs to increase the efficiency over big data. However, AES implementation on GPU exhibits limitations in terms of latency and hence, it might not be a suitable solution for high data rates in modern systems and applications. This often leads to a trade-off between system performance and security level. To address these challenges, we propose “ESSENCE”, a lightweight stream cipher scheme, which combines two different Pseudo-Random Number Generators (PRNG), and based on a dynamic key approach. The scheme achieves a high level of security with minimal latency and required resources when compared to existing cipher standards such as AES. Moreover, the implementation of the proposed dynamic key-dependent cipher scheme on GPU is more efficient compared to all existing AES implementations on GPUs. Experimental results indicate that the proposed cipher is highly efficient with a throughput more than 115 GB/s on a Titan X GPU, and more than 372 GB/s on a Titan V100 GPU. Thus, ESSENCE can be considered as a promising stream cipher candidate with high randomness degree (BigCrush of TestU01), periodicity, and key sensitivity.