Hi Dom,
You can try with following workarounds to correct your signal:
1.Here you are adjusting the phase linearly based on phase(2), which could be distorting the phase across harmonics. This may not be necessary and could be introducing a cumulative shift. Consider using the original phase values directly.
for y=1:length(phase)
phase2(y, 1)=phase(y)-phase(2)*(y-1);
end
2. Consider this revised approach to reconstruct the signal. Use 'order(q)' instead of 'q-1' , the harmonic number might not simply be 'q-1', so try:
x = mag(1);
for q=2:length(M)
x = x + mag(q)*sin(2*pi*order(q)*t + phase(q));
end
