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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
Icon for Honored Contributor rankHonored Contributor
11 years ago

I suggest you try:

1) single clean tone e.g. @ 0.01Fs by just setting your symbols to +1 only. This should lock first.

2)Next try single tone but add to it +1/-1 jitter (representing +1,-1,+1,-1 train of pulses) by setting symbols to +1/-1

Does it still lock?

3)Then move to full random symbols.

I have doubts that fully random BPSK will lock easily. You may need to extract a tone eventually through bandpass filter and target it for lock but let us see.