%This code is written in MATLAB 2022. It is the main code that shows the physical layer skew and application layer clock skew is same. Physical layer skew is computed using mu.txt values and application layer skew is computed using app_clock_tx16.txt and app_clock_rx11.txt values

clc
clear all
close all

load mu.txt
mu = mu.*0.2;
mu_sig = mu';
phy_offset=[];
for sym_considered = 1010:1000:22000 
    mc = least_sq_phy(mu_sig(1:sym_considered-1)');
    phy_offset(end+1) = mc(1)/2;
end

load app_clock_tx16.txt
tx_clock = app_clock_tx16;
load app_clock_rx11.txt
rx_clock = app_clock_rx11;
app_offset=[];
for timestamps_considered = 2:22 %length(tx_clock)
    off_clk = least_sq_app(tx_clock(1:timestamps_considered),rx_clock(1:timestamps_considered));
    app_offset(end+1)=off_clk(1)-1;
end
x_axis =[2:22];
figure;
plot(x_axis,phy_offset,'-b',x_axis,app_offset,'--r'); grid on;
xlabel('Number of Timestamps'); ylabel('Frequency Offset');
title('Application & Physical layer clock offset computation using LS')
legend('Physical layer offset','Application layer offset');
text(9,0.35*10^-5,['Physical layer offset = ' num2str(phy_offset(end))])
text(9,0.65*10^-5,['Application layer offset = ' num2str(app_offset(end))])

pp = ['Physical layer offset = ' num2str(phy_offset(end))];
pp = [pp 'Application layer offset = ' num2str(app_offset(end))]