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

Problems 505
9.8-1
A white process of PSD N/2 is transmitted through a bandpass filter H(f) (Fig. P9.8-1).
Represent the filteroutput n(t) in terms of quadrature components, and determine Sn c (f), Sn, (f),
nl, n;, and n 2 when the center frequency used in this representation is 100 kHz (i.e., fc =
100 X 10 3 ).
Figure P.9.8- 1
IH(/)1 2
2
1
9.8-2 Repeat Prob. 9.8-1 if the center frequency Jc used in the representation is not a true center
frequency. Consider three cases: (a)fc = 105 kHz; (b)fc = 95 kHz; (c)fc = 120 kHz.
9.8-3 A random process x(t) with the PSD shown in Fig. P9.8-3a is passed through a bandpass filter
(Fig. P9.8-3b). Determine the PSDs and mean square values of the quadrature components of
the output process. Assume the center frequency in the representation to be 0.5 MHz.
Figure P.9.8-3
(a)
H(f)
0
(b)
0.5 MHz