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Performance of Communication Systems Corrupted by Noise Chap. 7
p mb (f)
C1 C1 C2 C3 C4 C5
5 5 10 15 20 25 30
Figure P7–51
f (kHz)
modulates a DSB-SC transmitter. The DSB-SC signal is transmitted over an additive white
Gaussian noise channel. At the receiver the average power of the DSB-SC signal is P s and the
noise has a PSD of N 0 /2.
(a) Draw a block diagram for a receiving system with five outputs, one for each audio channel.
(b) Calculate the output SNR for each of the five audio channels.
7–52 Rework Prob. 7–51 for the case when the FDM signal is frequency modulated onto the main
carrier. Assume that the RMS carrier deviation is denoted by ∆F rms and that the five audio
channels are independent. No deemphasis is used.
7–53 Refer to Fig. 7–27 and
(a) Verify that the PCM curve is correct.
(b) Find the equation for the PCM curve for the case of QPSK signaling over the channel.
(c) Compare the performance of the PCM/QPSK system with that for PCM/BPSK and for the
ideal case by sketching the (S/N) out characteristic.
7–54 In Sec. 7–9, the performance of an ideal analog system is discussed. Using MATLAB, plot the
(S/N) out as a function of (S/N) baseband where both are expressed in dB units. Let B T /B = 12.