Help me develop DSP code for Costas loop

Can someone help me to know that how can I develop DSP code for Costas loop. I came to know that there might some problem arise due to NCO present on the board. Please, Help.

Re: Costas Loop

costal loop is actually used in the receiver end ie demodulator. actually when we try to demodulate the signal there we have to recover the original signal from the carrier so the costos loop helps to recover the signal by tracking the phase difference. frequency can be related to phase so by detecting the phase we can recover the original signal.

Look the document below attached.

Added after 1 minutes:

costal loop is actually used in the receiver end ie demodulator. actually when we try to demodulate the signal there we have to recover the original signal from the carrier so the costos loop helps to recover the signal by tracking the phase difference. frequency can be related to phase so by detecting the phase we can recover the original signal.

Look the document below attached.

Re: Costas Loop

I want to code this Costas loop and I want to cotrol the NCO digitally means i want to recover my Carrier digitally or we can say i have to generate the frequencies through numbers in digital form.

Please help me................