CodeIgniter Design Paterns

[eluser]Lazos[/eluser]
Hi.
I am doing my dissertation and I have to use design patterns and a framework for developing a CMS.
As for framework I am using CodeIgniter because it has great User Guide and very easy to use.

But I also have to use some design patterns and I am kind of lost. I try to read about them from books but still I do not really get it...

Can you post a link with simple PHP design patterns examples and also I would like to know what kind of design pattern is each class of CodeIgniter or at least some basic classes?

I am running out of time.
I would be grateful if you answer me these questions.
Thanks.