Receiver sensitivity equation in case of filter bandwidth > signal bandwidth

[makanaky]

Hi,

The digital receiver sensitivity equation is as follows :

Sensitivity = KTB+NF+(Eb/No)*R/B

Where B is the channel bandwidth

This may be rewritten as :

Sensitivity=KTR+NF+(Eb/No) ( by ommitting B with B)

So what if the filter bandwidth is >> signal bandwidth. This equation will surely be invalid, but how can I calculate the sensitivity then ?

Thanks