Honored Contributor
Honored Contributorwhat is your input? is it clean tone or bpsk signal.
Where is your model that works in matlab? a single tone should end up as dc i.e. two constants for I and Q if nco frequency is correctly matched to push input signal to zero freq.(baseband). but for bpsk signal I expect to see constellations of +/- on each I and Q or one circle if nco is not locked (still rotating symbols). The main difference between model and sim is that of resolution, truncations and loop delay (in unit samples) between nco updates. Groupdelay of filters doesn't make difference but it affects initial convergence time in both cases and equally.
