Indoor VLC means Communication is possible in a small range that is useful in home, office and small area environments. Indoor VLC is next level of Home automation system. Whenever people think about Indoor VLC first question is why we use this and what is a feature?

1) Minimum Data Speed is 1 Gbps

2) No Signal Loss

3) Light is Not harmed the human body

4) Reusable Concept of Light

5) More Secure

Now Look like advantages are so many compare to current Wireless techniques but one disadvantage is this concept covers the only small area. Now How many Area’s are covered we see in next post currently we measure an important parameter of VLC SNR(Singal to Noise Ratio) for 1 V LED. Here MATLAB code is attached. Run in code in MATLAB and enjoy a graph of SNR.

For this Program assume 1 V LED is located in (0,0) point.

clear all;

clc;

close all;

% SNR Performance For VLC SYSTEM %

% Coded BY Er. PANCHAL PRATIK

% pattu310@gmail.com

% Easy USe Consider Following Example

%

%

% BASIC PARAMETER REQUIRED %

Incidence = 70*pi/180;

TX_FOV = 70; % Transmitter Field Of View

RX_FOV = 90; % Receivers Field Of View

Tx = [2,2,2]; % Transmitter Location

%Rxp = [2,2]; % Receiver Location

W_Room = 4; % Width of Room

L_Room = 4; % Length of Room

H_Room = 2; % Height Between Transmitter and Receiver

R = 1; % Responsivity of Photodiode

Apd = 1e-4; % Area of PhotoDetector

Rb = 1e6; % Data rate of system

Iamp = 5e-12; % Amplifier Current

q = 1.6e-19; % Electron Charge

Bn = 50e6; % Noise Bandwidth

I2 = 0.562; % Noise Bandwidth Factor

PLED = 1; % Power Emitted by LED

index =1;

HLED = 1;

[W L] = meshgrid(-(W_Room/2) : 0.50 : (W_Room/2)); % Consideer Length of BLock for Room

xydist = sqrt((W).^2 + (L).^2);

hdist = sqrt(xydist.^2 + HLED.^2);

%D = Tx – Rx;

%d = norm(D);

%Incidence = acos()

A_Irradiance = ((Tx(3)-HLED)./hdist);

%I(index) = Irradiance*180/pi;

%if abs(Incidence <= RX_FOV)

p = TX_FOV ;

Tx_FOV = (TX_FOV*pi)/180;

% BASIC CALCULATION IN VLC SYSTEM %

% Lambertian Pattern

m = real(-log(2)/log(cos(Tx_FOV)));

% Radiation Intensity at particular point

Ro = real(((m+1)/(2*pi)).*A_Irradiance^m);

% Transmitted power By LED

Ptx = PLED .* Ro;

% Channel Gain ( Channel Coefficient Of LOS Channel )

%Theta=atand(sqrt(sum((Tx-Rx).^2))/H_Room);

HLOS = (Apd./hdist.^2).*cos(Incidence).*Ro;

% Received Power By PhotoDetector

Prx = HLOS.*Ptx;

% Calculate Noise in System

Bs = Rb*I2;

Pn = Iamp/Rb;

Ptotal = Prx+Pn;

new_shot = 2*q*Ptotal*Bs;

new_amp = Iamp^2*Bn;

% Calculate SNR

new_total = new_shot + new_amp;

SNRl = (R.*Prx).^2./ new_total;

SNRdb = 10*log10(SNRl);

% else

% SNRl = 0;

% SNRdb = 0;

% end

index = index + 1;

% Plot Graph %

figure;

mesh(W,L,SNRdb);

%mesh(SNRdb);

%ylim([0 30]);

title(‘SNR Distribution in Room’);

xlabel(‘Length of Room’);

ylabel(‘Width of Room’);

zlabel(‘SNR in dB’);

**Output : MATLAB graph**