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Altera_Forum
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11 years ago

Costas Loop oscillates in ModelSim while locks in MATLAB!

Hello again, I have designed a Costas Loop in MATLAB and it simulates very well... locking and recovering the carrier. Here are the results: http://www.alteraforum.com/forum/attachment.php?...
Altera_Forum's avatar
Altera_Forum
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11 years ago

Hi Kazem, I had a doubt about the NCO to be the reason.... I changed it into a DDS I wrote. Take a look at the result:

http://www.alteraforum.com/forum/attachment.php?attachmentid=10465&stc=1

It does converge! and phase error is 0! But data is diminished also... Why do think is this? I remember I faced something like that in Matlab but I don't remember how and why.