sm9_5

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Problem 9.5. The message signal of Problem 9.2 having a bandwidth W of 4 kHz is 
transmitted over the same noisy channel having a noise spectral density N0/2 of 2x10-17 
watts per hertz using single-sideband modulation. If the average received power of the 
signal is -80 dBm, what is the post-detection signal-to-noise ratio of the receiver? 
Compare the transmission bandwidth of the SSB receiver to that of the DSB-SC receiver. 
 
Solution 
From Eq. (9.23) 
 
2
SSB
post
0
SNR
2
cA P
N W
= 
 
with 
2
80 dBm
2
cA P = − , , and . The 4 kHzW = 170 104 −×=N
 
SSB
postSNR 18 dB= 
 
The transmission bandwidth of SSB is 4 kHz, half of the 8 kHz used with DSB-SC. 
 
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