# How do you calculate/compute/determine the spectral coverage of a frequency spectrum?

I'm comparing frequency spectrum of FSK, ASK, QPSK, and MSK. And I'm asked which has the least and greatest spectral coverage. Could someone enlighten me on how to get it?

• Could you define spectral coverage? – Naresh Mar 14 '13 at 16:10

R/W = (2*logM)/N