Need for modulation and Bandwidth requirement in SSB-SC AM wave

Modulation is required for

a.) Reducing noise while transmission
b.) Multiplexing the signals
c.) Reduction of Antenna height
d.) Reduction in the complexity of circuitry
e.) All of the above

Correct Answer: e) All of the above

Explanation:

Modulation is required as with modulation, the signal is transmitted at higher frequency that reduces the probability of addition of noise while transmission and reduces the height of antenna at the transmitter. With modulation, there is reduction in the complexity of circuitry and more signals may be transmitted using multiplexing technique.

Bandwidth required in SSB-SC signal is (f_m is modulating frequency):

a.) 2f_m
b.) < 2f_m
c.) > 2f_m
d.) f_m

Correct Answer: f_m

Explanation:

In an amplitude modulated wave, total bandwidth required is from f_c+ f_m to f_c- f_m

i.e. BW = 2f_m where f_c is carrier frequency.

In SSB-SC transmission, as the carrier and one of the sidebands are suppressed, the bandwidth remains as f_m.