Hi Sonal,
I understand that you are required to estimate the phase shift error ‘ps’ between two waves generated from the output of a Microwave Interferometer.
You may follow these steps to estimate ‘ps’
- To Minimize the difference between the I and Q waves, define a function that quantifies this difference.
- The `fminsearch` function is then used to find the value of ‘ps’ that minimizes this difference. It iteratively adjusts the value of ‘ps’ until it finds the one that best aligns the waves.
The below code provides an estimation of the phase shift error (ps) between the two waves by minimizing the difference between ‘I’ and ‘Q’ waves.
%Given values
phi = 0:0.2:4*pi;
ps = 0.2; % Initial guess for ps
A1 = 1;
A2 = 1.2;
Vdc1 = 0.1;
Vdc2 = 0.2;
npts = length(phi);
% Generate I and Q waves
I = A1*sin(phi) + rand(1, npts) + Vdc1;
Q = A2*sin(phi + (pi/2) + ps) + rand(1, npts) + Vdc2;
% Define function to minimize
fun = @(ps) norm(I - (A1*sin(phi) + Vdc1) - (A2*sin(phi + (pi/2) + ps) + Vdc2));
% Find ps that minimizes the difference between I and Q
estimated_ps = fminsearch(fun, 0); % Starting guess for ps is 0
disp(['Estimated phase shift error (ps): ', num2str(estimated_ps)]);
You may refer this documentation link for more information on ‘fminsearch’ function.
