Learning Cellular Technology

[saa]

could someone please point me to where i can learn the basics of cellular technology on an electronics (reverse-)engineering basis. in particular DCT4.

what does DCT4 stand for (discrete cosine transform?)

i am new to all this; i have a mathematical/theoretical physics/linux background but not really played on electronics level since age 5!

please forgive my ignorance.

any help is greatly appreciated.

saa