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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

oscillation is good sign as convergence of feedback loops takes time (convergence time) before it settles with some jitter in the steady state. It then may lose lock and re-acquire if upset. All these parameters are well known in control design.

Your matlab model may not be that good I assume. Moreover to match delays and latency and bit precision/truncation is no easy job. I suggest you stick with modelsim for now.