B. P. Lathi, Zhi Ding - Modern Digital and Analog Communication Systems-Oxford University Press (2009)

3.10 MATLAB Exercises 129
We multiply G q by H q and take the inverse DFT. The resulting output signal is shown in
Fig. 3.42d. Table 3.4 gives a printout of gk, G q , H q , Y q , and Yk ·
We have already found the 32-point DFT ( G q ) of g(t) in Example C3.2. The MATLAB
program of Example C3.2 should be saved as an m-file (e.g., "c32.m"). We can import
G q in the MATLAB environment by the command "c32". Next, we generate 32-point
samples of H q , multiply G q by H q , and take the inverse DFT to compute Yk • We can also
find Yk by convolving gk with hk .
c32;
q=0 :32; q=q' ;
for m=l : length (q}
if q(m} $>$=0 & q(m) $<$=7 , Hq (m} =l; end
if q(m) $>$=25 & q(m) $<$=31, Hq (m) =l; end
if q(m) $>$=9 & q(m) $<$=23, Hq (m} =0 ; end
if q(m) ==B & q(m} ==24, Hq (m) =0.5; end
TABLE 3.4
No. gk G q H q G q Hq Yk
0 8,000 8.000 0.9285
1 7,179 7.179 1.009
2 5,027 1 5.027 1.090
3 1 2,331 1 2.331 0.9123
4 1 0.000 1 0.000 0.4847
5 0.5 -1.323 -1.323 0.08884
6 0 -1.497 -1.497 -0.05698
7 0 -0.8616 1 -0.8616 -0.01383
8 0 0.000
0.000 0.02933
9 0 0.5803 0 0.000 0.004837
10 0 0.6682 0 0.000 -0.01966
0.5
11 0 0.3778 0 0.000 -0.002156
12 0 0.000 0 0.000 0.01534
13 0 -0.2145 0 0.000 0.0009828
14 0 -0.1989 0 0.000 -0.01338
15 0 -0.06964 0 0.000 -0.0002876
16 0 0.000 0 0.000 0.01280
17 0 -0.06964 0 0.000 -0.0002876
18 0 -0.1989 0 0.000 -0.01338
19 0 -0.2145 0 0.000 0.0009828
20 0 0.000 0 0.000 0.01534
21 0 0)778 0 0.000 -0.002156
22 0 0.6682 0 0.000 -0.01966
23 0 0.5803 0 0.000 0.004837
24 0 0.000 0.5 0.000 0.03933
0 -0.8616 -0.8616 -0.01383
26 0 -1.497 -1.497 -0.05698
27 0 -1.323 1 -1.323 0.08884
28 0.5 0.000 1 0.000 0.4847
29 2.331 1 2.331 0.9123
30 5.027 1 5.027 1.090
31 7.179 7.179 1.009
25