ANSWER ALL THE QUESTIONS MARKS
1.a) Determine frequncy response, impulse response for difference (6)
equation y(n)-(3/4)y(n-1)+(1/8)y(n-2)=x(n)
b)Given X(k) = {10, -2+2j, -2, -2-2j} (4)
find x(n) using IFFT- DIF algorithm.
c)By means of DFT and IDFT , Perform circular convolution for impulse (10)
response h(n)={1,2,3,4}to the input sequence x(n)={1,2,2,1}
2.An 8-point discrete time sequence is given by x(n) = {2,2,2,2,1,1,1,1}. (10)
Compute the 8-point DFT of x(n) using radix-2 DIT- FFT algorithm.
c) Obtain direct form and linear phase realization for
(6)
h(n)={0.225, 0.8, 0.75, 0.5, 0.75, 0.8, 0.225}
d) Obtain cascade realization for FIR filter (4)
y(n)-(3/4)y(n-1)+(1/8)y(n-2)=x(n)
3.a)Design a low pass filter with a frequency response (10)
Hd( ejω ) = e-3jw for -π /4 ≤ ω ≤ π /4
= 0 for π /4 | ω | ≤ π
Using Hanning window & N = 7.
b)Design a Butterworth filter using the bilinear method for the following (10)
specifications .Assume T=1sec
0.9 ≤ | H( ejω ) | ≤ 1 ; 0 ≤ ω ≤ π/2
jω
| H( e ) | ≤ 0.2 ; 3π/4 ≤ ω ≤ π
4. a)Draw the direct form I, II, cascade realization
y(n)= (3/4)y(n-1)-(1/8)y(n-2)+x(n)+(1/3)x(n-1 )
b) Obtain parallel realization for the difference equation (10)
y(n)= -0.1y(n-1)+0.72y(n-2)+0.7x(n)-0.252x(n-2)
(10)
1
5.a)Consider the transfer function H(Z)= H1(Z).H2(Z) where (10)
H1(Z)= 1/1-a1z-1 and H2(Z)=1/1-a2Z-1 .
Find the output roundoff noise power. Assume a1=0.7 and a2=0.8 and find
output roundoff noise power in cascade form if b= 3(excluding sign bit)
b)Write short notes on Down sampling and Up sampling (5)
c) Determine expression for output y(n) as shown in figure (5)
x(n) 4 12 3
y(n)