Fig. 2
Equivalence of the signal level-crossing model: a the input signal only containing band-pass (BP) noise, b the input signal only containing an FP pulse, c a threshold crossing due to BP noise only with V N =V TH , d A threshold crossing when the input is the summation of BP noise and an FP pulse with V N =V TH , e is the equivalent model of (d), where the input signal contains only BP noise while V TH changes to V N −A during an FP pulse arrival