Visible Light Communication Channel Model Research Articles

VLC channel model in underground mining scenarios with the extinction effect and shadowing effect

In this work, a novel, to our knowledge, visible light communication (VLC) channel model is proposed for underground mining scenarios taking into account the impact of coal dust particles and obstacles. Specifically, the extinction effect of the coal dust particles is analyzed on the basis of the Mie theory, and the quantitative formula of the influence on channel direct current (DC) gain is derived. Meanwhile, the effect of a random shadowing phenomenon is investigated and quantified with the geometric and statistical model considering the position, size, and shape of the obstacles. The channel impulse response, path loss, root mean square delay spread, and bit error rate (BER) are further investigated in two different underground mining scenarios, namely, a mining roadway and coal mine working face. Simulation results show that the shadowing effect plays a major role in the influence of DC gain attenuation. Furthermore, the BER performance is noticeably degraded due to the presence of coal dust particles and obstacles, especially when the receiver is located far from the transmitter. This work will benefit the design of the VLC systems in underground mines.

Joint precoding and power allocation in a FSO channel with signal-dependent noise.

To enhance the throughput of visible light communication (VLC), this paper investigates precoding and power allocation jointly in a free space optical channel with signal-dependent noise (SDN-FSO). With the presence of SDN from a light source, a more realistic multi-user multiple-input single-output (MU-MISO) VLC channel model is introduced. First, based on the entropy power inequality, a capacity bound for the SDN-FSO channel is derived under a MU-MISO scenario. Second, due to the nonnegativity of SDN-FSO input, a zero forcing constraint is introduced to alleviate multi-user interference. Third, from the perspective of resource allocation, min-max and total power budget constraints are taken into consideration. A non-convex joint optimization problem is formulated and divided into two subproblems, i.e.,the precoding subproblem and power allocation subproblem. Moreover, an iterative algorithm based on a concave and convex program and a simplified high signal-to-noise ratio approximation method are iteratively implemented in the precoding subproblem. For the power allocation subproblem, successive convex approximation is employed to ensure its optimality. Simulation results indicate that the proposed joint optimization methods can converge after about two iterations and accomplish a throughput improvement of up to 1∼3n a t s/s/H z as compared with the benchmarks for four different spacing scenarios. When channel state information is interfered with noise, the proposed methods still demonstrate their superior performance with varying degrees of noise.

R-AP's position-domain model for an RO-receiver and AP placement strategy for an uninterrupted link between the robotic arm and AP in the VLC network.

In the visible light communication (VLC) network, the optical link between the robotic arm and the access point (AP) is easily interrupted due to the random orientation of the receiver on the robotic arm. First, based on the VLC channel model, a position-domain model of reliable AP (R-AP) for a random-orientation receiver (RO-receiver) is proposed. The channel gain of the VLC link between the receiver and the R-AP is non-zero. The tilt-angle range of the RO-receiver is [0,π]. Given the field of view (FOV) angle and the orientation of the receiver, the R-AP's position domain of the receiver can be obtained by this model. Then, based on the R-AP's position-domain model for the RO-receiver, a novel AP placement strategy is proposed. Under this AP placement strategy, the number of R-APs for the RO-receiver is not less than 1, thereby effectively avoiding link interruption caused by the random orientation of receivers. Finally, it is proved by the Monte Carlo method that, under the AP placement strategy proposed in this paper, the VLC link of the receiver on the robotic arm can remain uninterrupted during the movement of the robotic arm.

Channel Characteristics and Link Adaption for Visible Light Communication in an Industrial Scenario.

Visible light communication (VLC) is one of the key technologies for the sixth generation (6G) to support the connection and throughput of the Industrial Internet of Things (IIoT). Furthermore, VLC channel modeling is the foundation for designing efficient and robust VLC systems. In this paper, the ray-tracing simulation method is adopted to investigate the VLC channel in IIoT scenarios. The main contributions of this paper are divided into three aspects. Firstly, based on the simulated data, large-scale fading and multipath-related characteristics, including the channel impulse response (CIR), optical path loss (OPL), delay spread (DS), and angular spread (AS), are analyzed and modeled through the distance-dependent and statistical distribution models. The modeling results indicate that the channel characteristics under the single transmitter (TX) are proportional to the propagation distance. It is also found that the degree of time domain and spatial domain dispersion is higher than that in the typical rooms (conference room and corridor). Secondly, the density of surrounding objects and the effects of user heights on these channel characteristics are also investigated. Through the analysis, it can be observed that the denser objects can contribute to the smaller OPL and the larger RMS DS under the single TX case. Furthermore, due to the blocking effect of surrounding objects, the larger OPL and the smaller RMS DS can be observed at the receiver with a low height. Thirdly, due to the distance dependence of the channel characteristics and large time-domain dispersion, the link adaption method is further proposed to optimize the multipath interference problem. This method combines a luminary adaptive selection and delay adaption technique. Then, the performance of the link adaption method is verified from four aspects through simulation, including the signal-to-noise (SNR), the RMS DS, the CIRs, and the bit-error rate (BER) of a direct-current-biased optical orthogonal frequency division multiplexing (DCO-OFDM) system. The verification results indicate that our proposed method has a significant optimization for multipath interference.

A Wavelength-Dependent Visible Light Communication Channel Model for Underground Environments and Its Performance Using a Color-Shift Keying Modulation Scheme

Reliable wireless communications are crucial for ensuring workers’ safety in underground tunnels and mines. Visible light communications (VLC) have been proposed as auxiliary systems for short-range wireless communications in underground environments due to their seamless availability, immunity to electromagnetic interference, and illumination capabilities. Although multiple VLC channel models have been proposed for underground mines (UM) so far, none of these models have considered the wavelength dependence of the underground mining VLC channel (UM-VLC). In this paper, we propose a single-input, single-output (SISO), wavelength-dependent UM-VLC channel model considering the wavelength dependence of the light source, reflections, light scattering, and the attenuation due to dust and the photodetector. Since wavelength dependence allows us to model VLC systems more accurately with color-based modulation, such as color-shift keying (CSK), we also propose a wavelength-dependent CSK-based UM-VLC channel model. We define a simulation scenario in an underground mine roadway and calculate the received power, channel impulse response (CIR), signal-to-noise ratio (SNR), signal-to-interference ratio (SIR), root mean square (RMS) delay, and bit error rate (BER). For comparison, we also calculate these parameters for a monochromatic state-of-the-art UM-VLC channel and use it as a reference channel. We find that the inclusion of wavelength-dependency in CSK-based UM-VLC systems plays a significant role in their performance, introducing color distortion that the color calibration algorithm defined in the IEEE 802.15.7 VLC standard finds harder to revert than the linear color distortion induced by monochromatic CSK channels.

Configuring Reconfigurable Intelligent Surface for Parallel MIMO Visible Light Communications with Asymptotic Capacity Maximization

As an emerging technology, reconfigurable intelligent surface (RIS) has attracted increasing attention due to the ability to configure the wireless propagation environment. Parallel multiple-input multiple-output (MIMO) visible light communication (VLC) is suitable for some scenarios, e.g., multi-user time-division multiple access for indoor VLCs. The application of RIS in VLC is a promising trend in the future, and this paper investigates the employment of RIS in a parallel MIMO VLC system with asymptotic capacity maximization. To this end, the RIS-aided parallel MIMO VLC channel model is derived in this paper under the point source assumption, and then, as for the non-convex optimization problem, instead of searching exhaustively for the optimal solution, we propose a low-complexity near-optimal relaxing particle swarm optimization (RPSO) algorithm to optimize the RIS parameters. Meanwhile, we discover that the convex relaxation is an effective method for the optimization problems. Finally, numerical results indicate the effectiveness of the proposed design of RIS, and meanwhile, the asymptotic capacity can be improved to a great degree by adopting RIS in the parallel MIMO VLC system.

A survey on the integration of visible light communication with power line communication: Conception, applications and research challenges

The extensive enhancement of wireless communication industry over the last decade revolutionized the change of our daily life. In this scenario, it becomes utmost difficult for the network providers to cater the needs of the end users. Consequently, this mandates the necessity to rely on alternative communication-based technologies. Therefore, one such communication is visible light communication (VLC) which is regarded as a promising complement to radio frequency (RF) based wireless communication. The renowned nature of VLC is that it renders simultaneous illumination and communication by utilizing light emitting diodes (LEDs). However, VLC by itself cannot be employed directly as an information source. Therefore, this necessitates for VLC to be connected to a backhaul network to furnish communication. Based upon these grounds, power line communication (PLC) turns out to be the most feasible communication technology which reinforces as an excellent communication backbone for VLC systems. Predominantly, the inherent benefit offered by the integrated PLC–VLC systems is that the existing power line infrastructure can be leveraged to supply power to the LED, while the energy-efficient LED-based illumination systems render wireless support. Accordingly, this paper presents a comprehensive review of the integrated PLC–VLC systems, physical layer aspects which includes detailed study on PLC–VLC channel modeling and modulation techniques. In addition, this survey focuses in detail on the multiple access techniques and clearly discusses several technical aspects that are associated with the cascaded PLC–VLC systems as well as highlights the current state-of-the-art research aspects in the directions of hybrid PLC-VLC-RF systems. Additionally, this survey outlines the societal applications of PLC–VLC systems which includes the applications of PLC–VLC in hospitals, aircrafts, military, Internet of Things (IoT) devices, etc., as well as summarizes the challenges that are of paramount important while designing high speed integrated PLC–VLC systems.

Research on blind equalization algorithm of high-speed visible light communication signal based on machine learning and Marketing

In order to solve the problem of high communication error rate caused by inter symbol interference in high-speed visible light communication signal blind equalization algorithm, a high-speed visible light communication signal blind equalization algorithm is designed based on machine learning. The visible light communication channel model is constructed, and a fusion length limited coding mode is set to make the signal transmitted by visible light communication more in line with the overall response of the channel. The decision feedback equalizer is selected as the equalizer, and the channel cascade impulse response condition is set to compensate the distorted output of the channel. The blind equalization algorithm is designed to classify the data by unsupervised learning, and the extreme point of the error function is found through iterative calculation to optimize the equalizer. The simulation results show that under the same SNR test conditions, the bit error rate of the proposed algorithm is significantly lower than that of the blind equalization algorithm based on LMS and BP neural network. Under the condition of SNR = 20dB, the bit error rate is significantly reduced to the order of 10-5, with high communication quality. The VLC system uses an LED backlight display with a CMOS camera. In general, this panel is used to display marketing information. By adjusting the brightness of the CMOS camera's rolling shutter effect (RSE), additional data, such as dynamic content, may be wirelessly sent. NR (noise to signal) ratio of VLC can't keep up with the variety of material being shown on the screen. It is possible to significantly enhance the CMOS RSE pattern decomposition by using a grayscale value distribution (GVD) and a machine learning method (MLA).

An Enhanced VLC Channel Model for Underground Mining Environments Considering a 3D Dust Particle Distribution Model.

Underground Mining (UM) is a hostile industry that generally requires a wireless communication system as a cross-cutting axis for its optimal operation. Therefore, in the last five years, it has been shown that, in addition to radio-frequency-based communication links, wireless optical communications, such as Visible Light Communication (VLC), can be applied to UM environments. The application of VLC systems in underground mines, known as UM-VLC, must take into account the unique physical features of underground mines. Among the physical phenomena found in underground mines, the most important ones are the positioning of optical transmitters and receivers, irregular walls, shadowing, and a typical phenomenon found in tunnels known as scattering, which is caused by the atmosphere and dust particles. Consequently, it is necessary to use proper dust particle distribution models consistent with these scenarios to describe the scattering phenomenon in a coherent way in order to design realistic UM-VLC systems with better performance. Therefore, in this article, we present an in-depth study of the interaction of optical links with dust particles suspended in the UM environment and the atmosphere. In addition, we analytically derived a hemispherical 3D dust particle distribution model, along with its main statistical parameters. This analysis allows to develop a more realistic scattering channel component and presents an enhanced UM-VLC channel model. The performance of the proposed UM-VLC system is evaluated using computational numerical simulations following the IEEE 802.1.5.7 standard in terms of Channel Impulse Response (CIR), received power, Signal-to-Noise-Ratio (SNR), Root Mean Square (RMS) delay spread, and Bit Error Rate (BER). The results demonstrate that the hemispherical dust particle distribution model is more accurate and realistic in terms of the metrics evaluated compared to other models found in the literature. Furthermore, the performance of the UM-VLC system is negatively affected when the number of dust particles suspended in the environment increases.

An Indoor Visible Light Positioning System for Multi-Cell Networks

Indoor positioning systems based on visible light communication (VLC) using white light-emitting diodes (WLEDs) have been widely studied in the literature. In this paper, we present an indoor visible-light positioning (VLP) system based on red–green–blue (RGB) LEDs and a frequency division multiplexing (FDM) scheme. This system combines the functions of an FDM scheme at the transmitters (RGB LEDs) and a received signal strength (RSS) technique to estimate the receiver position. The contribution of this work is two-fold. First, a new VLP system with RGB LEDs is proposed for a multi-cell network. Here, the RGB LEDs allow the exploitation of the chromatic space to transmit the VLP information. In addition, the VLC receiver leverages the responsivity of a single photodiode for estimating the FDM signals in RGB lighting channels. A second contribution is the derivation of an expression to calculate the optical power received by the photodiode for each incident RGB light. To this end, we consider a VLC channel model that includes both line-of-sight (LOS) and non-line-of-sight (NLOS) components. The fast Fourier transform (FFT) estimates the powers and frequencies of the received FDM signal. The receiver uses these optical signal powers in the RSS-based localization application to calculate the Euclidean distances and the frequencies for the RGB LED position. Subsequently, the receiver’s location is estimated using the Euclidean distances and RGB LED positions via a trilateration algorithm. Finally, Monte Carlo simulations are performed to evaluate the error performance of the proposed VLP system in a multi-cell scenario. The results show a high positioning accuracy performance for different color points. The average positioning error for all chromatic points was less than 2.2 cm. These results suggest that the analyzed VLP system could be used in application scenarios where white light balance or luminaire color planning are also the goals.

Effects of Optical Beams on MIMO Visible Light Communication Channel Characteristics

Under 5G envision, for pushing visible light communication (VLC) channel model evolution to various non-Lambertian beams, this paper introduces the typical commercial non-Lambertian beams, such as Luxeon rebel and side emitter, into the conventional analytical VLC channel model. The numerical results illustrate that the non-Lambertian beams can significantly affect the VLC channel frequency response characteristics. Compared with the traditional Lambertian beam, Side Emitter optical beam could naturally bring up to about 56.8% VLC multi input multi output channel capacity deviation, which objectively opens a new discussion dimension for enhancing VLC transmission performance.

Effect of scattering phase function on underwater visible light communication channel models

Non-sequential ray tracing simulations are commonly employed to model underwater visible light communication (VLC) channels. The accuracy of such simulations highly depends on how well the optical properties of water (i.e., absorption and scattering) as well as scattering phase function (SPF) are modeled in the simulation. Existing empirical models are only a function of chlorophyll concentration and particle composition and are independent of refractive index, size and concentration of particles. In this paper, we carry out an underwater VLC channel modeling study using the Mie SPF which provides a full description of the scattering from phytoplankton particles which dominate the optical properties of most oceanic waters. We obtain the channel impulse response (CIR) based on an extensive non-sequential ray tracing study and calculate the fundamental channel parameters such as channel gain and delay spread. Comparison of CIRs reveals out that deployment of simplified SPF models results in the overestimation of path loss with respect to Mie SPF. Our results clearly demonstrate the importance of selecting realistic SPF models for an accurate underwater VLC channel modeling. While highlighting the channel models, we discuss adaptive modulation technique to maximize the data rate under the constraint of a targeted bit error rate. Besides, the maximum achievable distance is also determined both in terms of analytical guarantees and computer simulations. The results reveal that larger transmission distances can be achieved through Mie SPF channel model.

Outdoor Visible Light Communication Channel Modeling under Smoke Conditions and Analogy with Fog Conditions

Visible Light Communication (VLC) has gained popularity in research and business in the last decade. This technology aims to combine lighting and communication into a single device. For now, this technology has been thoroughly studied for an indoor environment, but it is sufficiently mature nowadays to consider its outdoor-environment potentials. The key outdoor challenges are the weather variabilities and smoke particles in cities due to pollution or fires. The aim of this is the study and quantification of the weather and smoke particles’ impact on a short-range optical communication thanks to a simulator. This article’s novelty is the inclusion of the effects of smoke in a short-range outdoor VLC system channel model. This smoke model, which comes from the fire engineering field, states that smoke attenuation is independent of the wavelength, starting from high visibility to 5 m. The visibility represents the distance up to which an object can be distinguished against the background. The effects of fog and smoke are studied in the case of two outdoor VLC scenarios. Smoke and fog models have analogous equations to express the optical attenuation they induce, using the visibility concept. Taking into account the actual light-emitting diode (LED) lamp radiation pattern, the simulator computes the power at the receiver side and the channel attenuation coefficients for a given fog or/and smoke outdoor setting. The main result drawn in this paper is that the channel attenuation levels due to fog and smoke are both in the same order of magnitude, starting from the visibility of about 1 km. The attenuation induced by fog is higher under this threshold of 1 km.

Photo detector-based indoor positioning systems variants: A new look

Indoor positioning system (IPS) coupling with photo-detectors at the receiving end has gained much attention from the consumers. The accuracy level using the global positioning system (GPS) is not up-to-the-mark in the indoor environment. Meanwhile, visible light communication (VLC) employing the optical transmitter, e.g., light-emitting diodes (LEDs), is considered a promising candidate nowadays because of its enormous advantages. To better understand the VLC channel model, a comprehensive review is presented. An investigation of the LED-based IPS, employed for the position calculation using various techniques, is intensely discussed. The types of different photodetectors-based IPSs are elaborated along with the metrics. A comparison of various IPSs is developed to select the optimum one better. A new look of the IPS is proposed with extended features and better accuracy. A conclusion is drawn in this field for researchers to enhance VLC-based systems towards future research.

Indoor amplify-and-forward power-line and visible light communication channel model based on a semi-hidden Markov model

In this paper, the channel model of a multicarrier, indoor amplify-and-forward (AF) hybrid power-line communication (PLC) and visible light communication (VLC) channel is demonstrated. Measurements are obtained from different positions between the VLC transmitter and receiver in an indoor testbed with the aid of software-defined radios. Using the obtained measurements, channel models are derived using a semi-hidden Markov model (SHMM) with the aid of a Fritchman channel state representation model. The Baum-Welch algorithm is then used to re-estimate and validate the derived models. Results presented show the error-free run distribution in the hybrid channel and the probability of error from the obtained measurements. The re-estimated probability of error (P¯e) of each measured indoor scenario is also seen to match the corresponding measured Pe, showing the validity of the derived SHMM models.

A VLC Channel Model for Underground Mining Environments With Scattering and Shadowing

Underground mining is an industry that preserves the miners' safety and efficiency in their work using wireless communication systems as a tool. In addition to communication links characterized by radio frequency signals, optical links in the visible light spectrum are under intense research for underground mining applications due to their high transmission rates and immunity to electromagnetic interference. However, the design of a robust visible-light communication (VLC) system for underground mining is a challenging task due to the harsh propagation conditions encountered in mining tunnels. To assist researchers in the design of such VLC systems, we present in this paper a novel channel model that incorporates important factors that influence the quality of the VLC link in underground mines. Features such as an arbitrary positioning and orientation of the optical transmitter and receiver, tunnels with irregular walls, shadowing by large machinery, and scattering by dust clouds are considered. These factors are integrated into a single modeling framework that lends itself for the derivation of compact mathematical expressions for the overall DC gain, the impulse response, the root mean square delay spread, and the received power of the proposed VLC channel model. Our analytical results are validated by computer simulations. These results show that the rotation and tilt of the transmitter and receiver, as well as the tunnels' irregular walls have a notorious influence on the magnitude and temporal dispersion of the VLC channel's line of sight (LoS) and non-LoS components. Furthermore, results show that shadowing reduces the LoS component's magnitude significantly. Our findings also show that scattering by dust particles contributes slightly to the total VLC channel gain, although it generates a large temporal dispersion of the received optical signal.

On the Effect of Multipath Reflections in Indoor Visible Light Communication Links: Channel Characterization and BER Analysis

Owing to its several advantages over other wireless schemes, visible light communication (VLC) shall be at the forefront of optical wireless communication technology. However, due to multipath reflections and spatial distribution of light-emitting diode (LED) transmitters, there is an inherent delay spread in the VLC channels. We perform a comprehensive quantitative study on the effect of several practical factors like LED semi-angle, wall reflectivity, number of reflections, number of LED panels, room size, and user locations on the channel delay parameters, namely RMS delay spread and coherence bandwidth of the channel. We present the detailed derivation of the multipath VLC channel model and incorporate the effect of inter-symbol interference in bit error rate (BER) performance of the multipath VLC system. We analyze the average BER of the system under different practical scenarios and determine the penalty in signal to noise ratio entailed by a change in the system parameters mentioned above. We conclude that it is sufficient to model up to three reflections in the VLC channel to emulate the effect of multipath propagation on the channel characterization and BER analysis of the system. The results and analyses presented herein provide critical insights into the effect of multipath reflections in indoor VLC links, particularly the BER performance and channel delay characteristics. We also provide some key recommendations for the design of practical VLC systems by outlining the data rates that can be served under different system configurations.

A Novel VLC Channel Model Based on Beam Steering Considering the Impact of Obstacle

In this letter, a novel channel model of a visible light communication (VLC) system was proposed with the impact of position, size, and shape of the obstacle taken into account. The illumination area of the light-emitting diode (LED) was divided into independent solid angles and the ray was transmitted in every solid angle by beam steering; then, the point cloud of the obstacle was determined by the received rays in photodetector (PD). Furthermore, the convex hull model was used to represent the point cloud for simplification, the complex VLC channel model was set up, and the expression of the channel impulse response (CIR) was derived. Five scenarios with different obstacles were simulated for analysis, and the results revealed that the position, shape, and size of the obstacle have deep impact on the channel characteristics of the VLC system. Besides, beam steering increased the uniformity of the signal-to-noise ratio (SNR) distribution and the available bandwidth. Monte Carlo (MC) simulation was also provided to confirm the correctness of the proposed channel model.

Mixture-Kernel Based Post-Distortion in RKHS for Time-Varying VLC Channels

Visible light communication (VLC) based systems are a viable green supplement to existing radio frequency based communication systems. However, it has been found that the performance of VLC based systems is impaired in conditions when the users are mobile with respect to the transmit luminaire. The relative motion of the mobile users with respect to the luminaire renders the overall VLC channel to be time-varying. Recently, the impact of user mobility on the overall channel impulse response has been modeled by a generalized time-varying VLC channel model, which necessitates for an efficient mechanism at the receiver to tackle this phenomenon. In addition to user mobility, the inter-symbol interference, and the nonlinear characteristics of the light emitting diode are major factors that limit throughput of a VLC-based communication system. To mitigate these impairments, existing techniques such as Volterra/Hammerstein based receivers suffer from modeling error due to truncation of the polynomial kernel till second order terms. Recently, sparse reproducing kernel Hilbert space (RKHS) based methods have been suggested that guarantee universal approximation with the reasonable computational simplicity. However, the choice of a single hyper-parameter restricts its ability to model time-varying channels/systems. Therefore, this paper proposes a novel RKHS based post-distorter that adaptively learns a sparse dictionary based on the incoming observations, and monitors validity of the dictionary based on a proposed metric in RKHS. In order to mitigate the time-varying VLC channel based on this metric, a criterion for clearing the contents of the existing dictionary is proposed, and the requirement to learn a new dictionary is detected. Furthermore, the concept of mixture-adaptive kernel learning is introduced in this work for the minimum symbol error rate (MSER) criterion. From the convergence analysis presented in this paper, faster mean squared error (MSE) convergence is proved for the mixture-kernel based post-distorter. Additionally, it is also proven that for a given step-size, the proposed mixture-kernel MSER post-distorter always converges to a lower MSE as compared to the classical single-kernel MSER.

Strategy-Based Gain Ratio Power Allocation in Non-Orthogonal Multiple Access for Indoor Visible Light Communication Networks

Visible light communication (VLC) is an evolving green communication technology for indoor wireless communication networks. VLC utilizes light-emitting diodes (LEDs) for both illumination and communication. To achieve economic and energy-efficient communications, non-orthogonal multiple access (NOMA) improves the system throughput by enhancing spectral efficiency. In indoor VLC networks, the gain ratio power allocation (GRPA) of NOMA allocates greater signal power to the users of poor channels to achieve both fairness and high data rate. However, current GRPA strategies developed for radio frequency channels are not necessarily effective in all VLC channel and illumination cases. This study makes the following contributions. First, a GRPA strategy based on VLC channels is proposed that modifies the power counting and channel proportions enhance the NOMA-VLC throughput. Second, owing to difficulties of directly analyzing NOMA-VLC throughput, an alternative lower bound based on a VLC channel model to facilitate throughput comparisons is proposed. It is proved that the proposed alternative lower bound is asymptotic and compact with respect to NOMA-VLC throughput. Third, for the case of LED heights greater than 1 m, a local extremum solution using the proposed strategy is analytically demonstrated based on the alternative bound of VLC network throughput. Then, for the case of LED heights smaller than 1 m, the necessary but not sufficient condition under which the proposed strategy outperforms previous strategies is provided in VLC scenarios. Finally, the experimental results demonstrate the compactness of the proposed alternate lower bound and the advantages of the proposed strategy.