About Tutorial: Link Budgets Eb/No

[bepraising]

Hello,

I am an engineering undergraduate student. I find your site because I cannot follow with the class and I have many concept that I could not understand what the lecturer said. When I was in a state of helplessness and type "help" and "communication system" in google, I find your site. Your site is really great and I could understand the meaning very easily.

However, I have a stupid question. When I read the tutorial "link budgets", I learnt that the formula Eb/No. But why in example 2, it is eb - No (divide becomes a minus)?

Thank you for reading my question,
Chris

[jibeem]

In the example 2, the equation is in dB. Therefore, dividing (resp. multiplying) in the real world is equivalent to substracting (resp. adding) in the logarithmic world.