Underwater visible light communication (UVLC) is of great interest to the military, industry, and scientific community. In this paper, a long-distance UVLC system designed, where half power angle light-emitting diode (LED) narrowed enhance optical intensity at transmitter, single photon avalanche (SPAD) employed receiver improve detection sensitivity. A two-term exponential channel model long distance with SPAD established, parameters are obtained by Monte Carlo numerical simulation....

In conventional multi-input multioutput (MIMO) visible light communication (VLC) techniques such as repetition coding (RC), spatial multiplexing (SMP), and modulation (SM), the transmitted symbols through different light-emitting diodes located space are usually generated from unipolar pulse amplitude constellations independently. this letter, we propose a novel constellation design for MIMO indoor VLC systems, in which two spaces collaborate so closely that average optical power is...

Massive multi-input multi-output (MIMO) has great potential to improve transmission rate of visible light communication (VLC) systems. However, high inter-channel interference (ICI) is the main factor that seriously influences performance. In this letter, with channel state information (CSI) known at transmitters, a general criterion balancing spectral efficiency and error performance established by analyzing special features MIMO-VLC. Based on criterion, channel-adapted spatial modulation...

The limited modulation bandwidth and the non-linearity nature of LEDs are key challenges to visible light communication. In general, one LED lamp consists multiple chips. this letter, these chips used for parallel transmission though multi-LED phase-shifted OOK (MP-OOK) modulation. For MP-OOK, efficiency is approximate N times that conventional ( number chips). each branch, format OOK. Hence, MP-OOK has a better anti-nonlinearity performance than other high-order formats, such as DC-biased...

Since indoor visible light communication (VLC) modulates the information into beams emitted from light-emitting diodes, channel gain is often modeled as Lambertian model. For different spatial locations of transmitters and receivers, for VLC directly changes with several related geometrical parameters. The distinct feature makes ergodic capacity that radio-frequency communication. However, issue has not been studied currently. In this paper, we propose lower bounds on point-to-point...

A two-step process is proposed for the formation of c-axis aligned (Bi,Pb)2Sr2Ca2Cu3O10+δ [Bi(2:2:2:3)] platelets in a silver sheath. The involves: (1) (Bi,Pb)2Sr2CaCu2O8+δ at early stage heat treatment and (2) subsequent intercalation Ca–Cu–O layers to form Bi(2:2:2:3). This based on measurements rocking curves alignment two theta scans Bi(2:2:2:3) conversion ratio, both by transmission x-ray technique, quantitative study phase due into existing Bi(2:2:1:2) electron microscopy.

Owing to the line-of-sight characteristics in indoor visible light communication (VLC) systems, different geometrical locations of transmitters and receivers provide distinct channel correlations, thus bringing various impacts on conventional multiple-input multiple-output (MIMO) techniques. In this letter, by taking full advantage state information (CSI) available at both transmitter receiver, we present an optimal constellation for 2 × MIMO-VLC system, where signal vectors are selected...

Multi-input multi-output (MIMO) holds great potential in the high-speed transmission of visible light communication (VLC). However, as for current MIMO-VLC techniques, error performance is improved by wasting spatial resources, which just drops core advantage within an MIMO structure. Moreover, they cannot change over channel, greatly limits their application range. In this paper, a general design criterion channel-adaptive space-collaborative constellation (CASCC) established systems....

There is Poisson slot noise generated by the single photon avalanche diode (SPAD) and Gaussian thermal transimpedance amplifier, respectively, if an analog SPAD detector applied in visible light communication (VLC) system. In this letter, for long distance SPAD-based underwater VLC system, a fast blind multiple-symbol detection (MSD) algorithm developed under pure model. And then, MSD based on generalized maximum-likelihood rule Poisson-Gaussian (P-G) mixed model proposed. A Anscombe...

According to our experimental observation, the effect of dead time caused by quenching circuit single photon avalanche diode (SPAD) devices could affect system performance significantly. Hence, we propose a corresponding synchronization scheme and fast blind union detection (FBUD) algorithm for received photon-counting pulse waveform considering time. To verify proposed theory under long distance turbulence fading channel, demonstrate SPAD-based visible light communication with red...

As a spatial diversity transmission scheme, repetition code (RC) is conjectured to be optimal in the sense of error performance for an intensity modulated direct detection multi-input-multi-output optical wireless communication (IM/DD MIMO-OWC) over log-normal fading channels. Despite fact that all experimental evidences thus far have strongly demonstrated this hypothesis indeed true, its mathematical proof remains long-standing open problem mainly due lack explicit signal design criterion...

In the industrial environment, positioning of mobile terminals plays an important role in production scheduling. Visible light (VLP) based on a CMOS image sensor has been widely considered as promising indoor technology. However, existing VLP technology still faces many challenges, such modulation and decoding schemes, strict synchronization requirements. this paper, visible area recognition framework convolutional neural network (CNN) is proposed, where training data LED images acquired by...

Covert communications hide the information transmission from a watchful adversary (Willie) while ensuring satisfactory decoding performance at legitimate receiver (Bob). In this paper, we propose covert scheme based on narrow signal waveband and nonlinear suppression effect of avalanche photodiodes (APDs) for water-to-air (W2A) optical wireless communication (OWC) systems. Narrow is selected given wavelength selection pattern which negotiated by transmitter receiver. Willie's detection...

We consider a typical indoor environment, where multiple light-emitting diode (LED) lamps are equipped, and each LED lamp is the base station of an optical cell. A faster-than-Nyquist signal design presented for multiuser multicell (FTNMM) visible light communication (VLC) broadcasting systems, all transmitters transmit independently with properly designed time delay to achieve times spectral efficiency. The performance FTNMM analyzed in view minimum Euclidean distance symbol sequence, it...

In this paper, we consider an outdoor visible light communication system, in which on-off keying (OOK) modulation is utilized through atmospheric turbulence-induced slow-fading channel. A new fast blind detection algorithm proposed by following the generalized likelihood ratio test (GLRT) principle. addition, a block coding scheme presented to solve unique identification issue and, thus, error floor problem.

In this paper, we consider a multiple-input-multiple-output optical wireless communication (MIMO-OWC) system in the presence of log-normal fading. scenario, general criterion for design full-diversity space code (FDSC) with maximum likelihood detector is developed. This reveals that high signal-to-noise ratio regime, MIMO-OWC offers both large-scale diversity gain, governing exponential decay error curve, and small-scale producing traditional power-law decay. Particularly two by unipolar...

In visible light communication (VLC) systems for automotive applications, different kinds of traffic data with intended priority are usually demanded transmission to meet an important requirement both driving safety and the simplicity a receiver, mainly due time urgency issue. For this need, concept called additively uniquely decomposable constellation (signal amplitude set) group (AUDCG) is proposed in paper transmit multilayer VLC through cooperation. Then, optimal AUDCG designed by...

In this paper, we consider a multiple-input single-output (MISO) outdoor visible light communications (VLC) system in which the channel state information (CSI) at receiver side is unknown and where coefficients are independent lognormal distributed. For such system, propose to take advantage of repetition coding scheme space dimension add fixed nonzero pilot bit head block ensure reliable blind estimation coefficients. Then, symbol-by-symbol maximum-likelihood (ML) with linear complexity for...

Visible light communications (VLC) using multi-color light-emitting diodes (LEDs) can support simultaneous high-speed data rate and high-quality lighting. However, since the radiation spectrum of LEDs has a limited width, spectral overlapping will result in cross talk even when optical filters are applied at receivers. Moreover, used for illumination wireless transmission meantime, both lighting quality communication performance must be considered VLC systems. In this paper, we consider...

In this paper, we consider a multiple-input-multiple-output optical wireless communication (MIMO-OWC) system suffering from log-normal fading. scenario, general criterion for the design of full large-scale diversity space code (FLDSC) with maximum likelihood (ML) detector is developed. Based on our criterion, FLDSC attained if and only all entries coding matrix are positive. Particularly 2×2 MIMO-OWC unipolar pulse amplitude modulation (PAM), closed-form linear satisfying by smartly taking...

In this letter, we study a multi-user multiple-input single-output (MU-MISO) visible light communication (VLC) system. The linear precoding for pulse amplitude modulation signal is developed with noisy channel state information (CSI). method, the formulated to achieve user fairness constraint of current range lighting emitting diodes. design got by an iterative algorithm involving convex optimization problems, and simplified strong error based on pseudo-inverse zero-forcing method....

In this letter, we consider a multi-user multiple-input single-output visible light communication system. A power-efficient linear precoding for zero-forcing (ZF) detection is developed with channel uncertainty, i.e., noisy state information (CSI) and outdated CSI. With the constraint of dynamic current range light-emitting diodes, proposed method capable minimizing total optical power guaranteeing user performance. Simulation results demonstrate that can achieve lower consumption than...

We consider an indoor multi-input single-output (MISO) visible light communication (VLC) system without channel state information at the transmitter. For such a system, energy-efficient time-collaborative modulation (TCM) constellation is first designed by minimizing total optical power subject to fixed minimum Euclidean distance. Then, new space-time transmission scheme proposed. Comprehensive computer simulations indicate that our proposed design always has better average error performance...