Cochin University of Science and Techology (CUST) 2008 B.Tech Electronics and Communications Engineering Signals and Systems - Question Paper
Signals and systems
EC/R! 404 NIC.NM S AND SYSTEMS
B. Tech Degree IV Semester Examination, April 2008
I .5*heme)
Time' 5 Hours * <*> tc>
I
<d>
I
- 9
i
<*
(0
U>
* ih)
j(n-l)
(ii) >(n)*nx(n)
Kind the DTFT of the rectangular pulse x{n) - A jmj <t A',
= o h>,v,. 1 ..
f '(plain stationary and non-stationary random processes s
List the properties of power spectral density Define noise figure
A receiver is connected to an antenna whose resistance is 500 . The equivalent nots resistance of (his receiver is 300. Determine the receiver's noise figure and its equivalent noise temperature What is threshold effect? Explain
PART - B
Test whether the fottowiftf SJgnafe *re energy signals
0> x(l).4' 'w(f(ri> x{t) .ix(f)
A continuous lime signal .r(f ) applied the input fa continuous nme I H nWem with unit impulse response k[t) Fwd the tHrtput v(/) given that
t)A A(f)ii(f-3)
Test whether ihe follow mg vtems are Vmear or noT (i) v(n(- jr(w) +
r*r %
!Am*w <y*e4tic*>
Maximum Markt; 100
(I * J ' 40)
Test whether the following s>stems are I. Linear 2. + 5>(/) +2 = x(f) (!) (hi) >(/)=* (2/+ I)x(/). |
3 Time invariant i' OR Obtam the * owner Transform of a single skied exponential function ? *(/) Also dra ( ipertrum (15) Find fee Z Transform of Iff FV (a) 0) m x(w) ~ Co*(h')u(n). (2x3 - 10) (Turn &*r) &>& What are the different properties of ROC? OR Fine the transfer function and impulse response of a discrete time L.TI system described by the difference equation. Explain 3 properties of DTFT. -iii) Probability density function is given by the expression fx{Xj = ae . Determine (i) The relationship between a and b (ii) Cumulative distributive function (iii) Probability that outcome lies between 1 and 2. OR Explain Gaussian and Rayleigh distribution function. What is random variable? Explain different types. What is angle modulation? Explain the effect of noise on conventional AM. Also derive S/N ratio. OR Explain pre emphasis and de-emphasize filtering with the help of filter characteristics and circuits.
|