## MATLAB Code : SNR distribution for indoor VLC

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()
%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
% 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;
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