How can established LOS-link for Indoor visible light communications using only one LED source?

Visible light communications

Answer 1

[abdullah qasim]

clear

clc

theta=70;

% semi-angle at half power

m=-log10(2)/log10(cosd(theta));

%Lambertian order of emission

P_total=2000;

%transmitted optical power by individual LED

Adet=1e-4;

%detector physical area of a PD

Ts=1;

%gain of an optical filter; ignore if no filter is used

index=1.5;

%refractive index of a lens at a PD; ignore if no lens is used

FOV=60*pi/180;

%FOV of a receiver

G_Con=(index^2)/sin(FOV);

%gain of an optical concentrator; ignore if no lens is used

lx=5; ly=5; lz=3;

% room dimension in metre

h=2.15;

%the distance between source and receiver plane

%[XT,YT]=meshgrid([?1.25 1.25],[?1.25 1.25]);

XT=0; YT=0;

% position of LED;

Nx=lx*10; Ny=ly*10;

% number of grid in the receiver plane

x=-lx/2:lx/Nx:lx/2;

y=-ly/2:ly/Ny:ly/2;

[XR,YR]=meshgrid(x,y);

% receiver plane grid

D1=sqrt((XR-XT(1,1)).^2+(YR-YT(1,1)).^2+h^2);

% distance vector from source 1

cosphi_A1=h./D1;

% angle vector

H_A1=(m+1)*Adet.*cosphi_A1.^(m+1)./(2*pi.*D1.^2);

% channel DC gain for source 1

P_rec=P_total.*H_A1.*Ts.*G_Con;

% received power from source 1;

P_rec_dBm=10*log10(P_rec);

surfc(x,y,P_rec_dBm);

% contour(x,y,P_rec_dBm);hold on

%mesh(x,y,P_rec_dBm);

%meshc(x,y,P_rec_dBm);

xlabel('X (m)');

ylabel('Y (m)');

zlabel('Received power (dBm)');

axis([-lx/2 lx/2 -ly/2 ly/2 min(min(P_rec_dBm)) max(max(P_rec_dBm))]);

[Muhammad]

If anyone planning to use this code, here is a small commentary on the code. The code simulates and visualizes the optical power distribution from a single LED source to assess its coverage and intensity on a planar surface (receiver grid). This is useful in applications like, Indoor visible light communication (VLC), Lighting design and Photodetector placement optimization in Li-Fi networking models.

Key Concepts:

1. Lambertian Radiation: Describes how light intensity varies with angle, typical for LEDs. The parameter mmm determines the beam's spread, calculated based on the semi-angle at half-power (θ\thetaθ).
2. Optical Power Calculation: The code computes the power received by a photodetector (PD) at various positions in a room, taking into account the geometry, LED characteristics, and other factors like optical filters or concentrators.
3. Spatial Grid: The room is divided into a grid, and the received power is calculated for each point.

Parameters Setup:

• theta=70: Half-power angle of the LED.
• m: Lambertian emission order, derived from θ\thetaθ.
• P_total: Total power emitted by the LED.
• Adet: Area of the photodetector.
• Ts, index, FOV, G_Con: Parameters for optical filters and concentrators.
• Room dimensions and source height (lx, ly, lz, h).

Grid and Source Setup:

• XT, YT: LED source position.
• Nx, Ny: Grid resolution for the receiver plane.
• [XR, YR]: Coordinates of points on the receiver plane grid.

Received Power Calculation:

• D1: Distance from the LED to each grid point.
• cosphi_A1: Cosine of the angle of incidence at each point.
• H_A1: Channel DC gain based on Lambertian model and inverse square law.
• P_rec: Power received at each grid point, incorporating optical properties.
• P_rec_dBm: Received power converted to dBm for visualization.

Visualization:

• surfc: 3D surface plot of received power distribution.
• Axis labels and bounds are defined to match the room dimensions and power range.

Also one can see the Python based coding for optical fibre communication, systems and networks

https://github.com/edsonportosilva/OptiCommPy/tree/main/examples

https://github.com/SagiRad/480-Gbps-Optical-Communication-System

Good Luck in modelling!

Answer 2

[shimels gbre ab abebe]

Hello every one can I olease source code for hand over mangment betwen VLC and RF

please ?

Answer 3

[Nandini Priya]

I NEED TRANSMISSION OF VIDEO USING LIFI TECHNOLOGY CAN ANYONE HELP ME?