Inorganic perovskite CsPbBr3 nanocrystals (NCs) are emerging, highly attractive light emitters with high color purity and good thermal stability for light-emitting diodes (LEDs). Their photo/electroluminescence efficiencies very important fabricating efficient LEDs. Here, we propose a novel strategy to enhance the efficiency of NCs through doping heterovalent Ce3+ ions via facile hot-injection method. The cation was chosen as dopant by virtue its similar ion radius formation higher energy...

In this letter, we apply the non-orthogonal multiple access (NOMA) technique to improve achievable sum rate of multiple-input multiple-output (MIMO)-based multi-user visible light communication (VLC) systems. To ensure efficient and low-complexity power allocation in indoor MIMO-NOMA-based VLC systems, a normalized gain difference (NGDPA) method is first proposed by exploiting users' channel conditions. We investigate performance an 2×2 system through numerical simulations. The obtained...

Cubic phase CsPbI3 quantum dots (α-CsPbI3 QDs) as a newly emerging type of semiconducting QDs hold tremendous promise for fundamental research and optoelectronic device applications. However, stable sub-5 nm-sized α-CsPbI3 have rarely been demonstrated so far due to their highly labile ionic structure low stability. Here, we report novel strontium-substitution along with iodide passivation strategy stabilize the cubic CsPbI3, achieving facile synthesis series controllable sizes down nm. We...

Smart factory under Industry 4.0 and industrial Internet of Things (IoT) has attracted much attention from both academia industry. In wireless networks, IoT devices have different quality-of-service (QoS) requirements, ranging ultra-reliable low-latency communications (URLLC) to high transmission data rates. These networks will be highly complex heterogeneous, as well the spectrum energy resources are severely limited. Hence, this article presents a heterogeneous radio frequency (RF)/visible...

Abstract The photoluminescence quantum yield (PLQY) of CsPbBr 3 perovskite nanocrystals (NCs) prepared by the hot‐injection method can exceed 90%, which have attracted intensive attention for white light‐emitting diodes (WLEDs). However, whole experiment requires air isolation and relatively high temperature. In addition, poor stability NCs impedes their applications. Here, a facile is reported to synthesize @ZrO 2 at room temperature in air. Owing using ZrO coated NCs, not only present PLQY...

In this paper, a low-complexity time-difference-of-arrival (TDOA) based indoor visible light positioning (VLP) system using an enhanced practical localization scheme on cross correlation is proposed and experimentally demonstrated. The TDOA offers two advantages: 1) the use of virtual local oscillator to replace real for at receiver side so as reduce hardware complexity; 2) application cubic spline interpolation function rigorous requirement sampling rate enhance time-resolution correlation....

With the growing intelligence needed on Internet of Vehicles (IoV), seamless edge computing services for sixth generation (6G) vehicle-to-everything (V2X) applications require three-dimensional (3D) and ubiquitous networking coverage to realize intensive tasks data offloading. In high mobility fast-changing vehicular environment, 6G V2X networks supporting (VEC) need be more flexible, smart, adaptive. this article, an intelligent unmanned aerial vehicle (UAV)-assisted VEC system is...

Due to massive parallelism, huge storage, and ultralow power consumption characteristics of deoxyribonucleic acid (DNA), we propose a secure orthogonal frequency-division multiple access passive optical network (OFDMA-PON), using chaos encryption DNA encoding. In this scheme, the transmitted bit data are interleaved according operation rules, encoding rules randomly controlled by chaotic map. This can improve complexity random characteristic encrypted sequences. A physical layer secures...

This paper proposes a chaotic constellation transformation (CCT) technique for physical-layer security enhancement in orthogonal frequency-division multiple access based passive optical networks (OFDMA-PONs). The CCT is performed by using an advanced cat map whose control parameters are generated cross map. Moreover, pilot-aided key agreement scheme proposed to ensure that the keys securely distributed between transmitter and receiver. A 18.86 Gb/s encrypted 16-ary quadrature amplitude...

Due to severe inter-cell interference (ICI), the signal-to-interference-and-noise ratio (SINR) suffers from very significant fluctuation in indoor multi-cell visible light communication (VLC) systems, which greatly limits overall system performance. In this paper, we propose and evaluate a generalized angle diversity receiver (ADR) structure reduce SINR VLC systems. The ADR consists of one top detector multiple inclined side detectors. an using ADR, inclination detectors is optimized order...

Abstract The poor stability of lead‐free Cs 3 Cu 2 Cl 5 nanocrystals (NCs) is the main impediment for their broad practical applications. Here, a sol‐gel reaction using tetraethoxysilane (TEOS) as silica coating precursor to prepare @SiO x NCs proposed. Due efficient passivation and robust protection SiO shells on surface, solution films exhibit high photoluminescence quantum yield 98% 76%, respectively, improved against water heat. are then used fabricate warm white light‐emitting diodes...

In this article, we study the application of unmanned aerial vehicle (UAV) for data collection with wireless charging, which is crucial providing seamless coverage and improving system performance in next-generation networks. To end, propose a reinforcement learning-based approach to plan route UAV collect sensor from devices scattered physical environment. Specifically, environment divided into multiple grids, where one spot hovering as well charging located at center each grid. Each grid...

In this paper, we consider a light fidelity (LiFi)-enabled bidirectional Internet of Things (IoT) communication system, where visible and infrared are used in the downlink uplink, respectively. order to efficiently improve energy efficiency (EE) LiFi-IoT non-orthogonal multiple access (NOMA) with quality-of-service (QoS)-guaranteed optimal power allocation (OPA) strategy is applied maximize EE both uplink channels. We derive closed-form OPA sets based on identification decoding orders...

Abstract Due to the broadband emission induced by self‐trapped excitons (STEs), low‐dimensional hybrid lead halides are regarded as an emerging class of highly efficient light emitters. However, toxic element impedes their commercial application. Here, a new air‐stable lead‐free metal halide [Na(DMSO) 2 ] 3 SbBr 6 with 0D structure constituted [SbBr octahedral and units is synthesized at room temperature, which exhibits high photoluminescence quantum yield 60% ultra‐broadband yellow centered...

In this paper, a dual-parameter liquid level and refractive index (R.I.) sensor is fabricated using three pieces of bare polymer optical fibers (POFs), which can independently simultaneously sense the R.I. The proposed design utilizes twisted coupling technique, in two are coupled with macro-bending. measurement depends on loss, where light transmitted to emission fiber (EF) acceptor (AF). measure depths up 125 mm sensitivity 8.03 nW/mm. Moreover, sensing macro-bending (TCMB) EF generates...

With the rapid development of Internet Things (IoT) in smart city, grid, and industry, indoor communication positioning are important for IoT. However, radio-frequency (RF)-based wireless networks may fail to guarantee different quality-of-service (QoS) requirements devices, due limited bandwidth, severe interference, multipath reflections. Hence, this article presents a new integrated visible light (VLC) VLC (VLCP) network IoT provide both high-speed high-accuracy services. As consists...

Visible light communication (VLC) using multiple-input multiple-output (MIMO) has great potential for future high-data-rate indoor wireless communications. Owing to the dual function of white light-emitting diodes (LEDs), i.e., illumination and functions, both coverages need be evaluated when implementing an MIMO-VLC system. In this paper, we present a comprehensive investigation Two techniques are applied in system coverage improvement, including non-Hermitian symmetry orthogonal frequency...

Visible light communication (VLC) systems utilizing conventional superposition coding/successive interference cancellation (SPC/SIC)-based non-orthogonal multiple access (NOMA) suffer from the error propagation effect due to imperfect SIC. In this letter, we propose a flexible-rate SIC-free NOMA technique for downlink VLC systems, based on constellation partitioning coding (CPC) and uneven demapping (UCD). By using CPC/UCD, SIC is not required hence can be eliminated in NOMA-based systems....

For joint peak-to-average power ratio (PAPR) reduction and physical layer security enhancement, we propose a chaos IQ-encryption-based optimal frame transmission technique in an orthogonal frequency-division multiple access-based passive optical network (OFDMA-PON). The IQ-encryption is utilized to enhance the security. In encrypting, in-phase (I) quadrature-phase (Q) parts of quadrature amplitude modulation (QAM) symbols are coded with two phase sequences separately, which generated using...

Indoor location-based services are becoming crucial parts of smart living, manufacturing, and all kinds the Internet Things. Visible light-based positioning (VLP) system is one cost-efficient RF radiation-free solutions. However, conventional received signal strength (RSS)-based VLP suffers inaccurate modeling intensity variations, especially in 3-D cases. Hence, we propose an artificial neural network (ANN)-based approach for accurate with on-site data. Likewise, proposed also proved...