I am working on BPSK with sound waves a carrier waves.
Actually I am modulating my data with some known sync bits along with the information I need to send. So the things I will be having at demodulation side is these sync bits and carrier wave.
So I am modulating these sync bits with carrier and cross correlating this modulated (over sync bits) wave with received wave at the transmiter. By doing this I want to find the exact time position (where these sync bits appear in received wave).
For this I am first crosscorelating received wave and my sync wave then, when I plot it I wil surely get a maximum where the sync wave in both signals coincide.
But I am not sure if this maximum is the position I need (when there is a DC offset or large amplitudes in the received signal, it can also create an extreme value)
So to overcome this, I autocorelated my sync wave with itself and took the absolute difference between the all the values of crosscorelated matrix and autocorelated value. Then I assumed which ever value has the least value as the synced location.
This is also not working (I think as iam not sure that the location iam getting is midpoint of sync or starting of sync). Is this approach correct?
Or are there any other approaches to find the starting sync position in received wave?
I also needed help in knowing whether if we use the first method (wher evr maxima comes in crosscorelation taking tht as sync location) is this location I got, is sync starting location or midpoint of sync?