3. • Here the signal s(t) is distorted by noise n(t) and
applied to the input of the integrate and dump filter.
• The capacitor is discharged fully at the beginning of
bit interval(by closing Sw1 switch),the integrator then
integrates the noisy input signal over one bit period.
4. • For a square pulse input the output would be triangular,
the magnitude of vo(t).
• At t=T the o/p magnitude is maximum.
• Depending on the value of vo(T),the decision is taken
whether the transmitted bit is 1 or 0.
• The dump switch Sw1 is closed momentarily to
discharge the capacitor to receive the next bit.
21. summary
• To perform detection the receiver observes the received
signal for the duration of one symbol and guesses which
particular symbol was sent according to some set of rules.
• In coherent detection the receiver is assumed to be in
possession of exact replicas of the transmitted signals.
• In coherent detection a source of error in decision making
process is additive thermal noise at the receiver
input ,which is modelled as Gaussian noise of zero mean
and constant power spectral density.
