Website: www.cst.ur.ac.rw
SCHOOL OF ENGINEERING
DEPARTMENT OF ELECTRICAL ENGINEERING
YEAR 3
2018_2019
SEMESTER ONE
Group members:
NAMES
REGISTRATION
NUMBERS
ILAB REPORT of Communication Engineering
Lecturer: ZIMULINDA FRANCOIS
DATE: 20 DECEMBER 2018
Question1
What feature of the multiplier module’s output suggests that it’s a DSBSC signal?
 No carrier signal ,
According to the formular of AM with carrier
 If you look at the envelopes closely , you will notice that they are not the same shape as the
message as is the case with AM .
Question2
The DSBSC signal is a complex waveform consisting of more than one signal. Is one of the signals a 2kHz
sinewave? Explain your answer.
Answer2:YES because 2kh sine wave is considered as message signal
Question3: For the given inputs to the multiplier module, how many sinewaves does the DSBSC signal
consist of, and what are their frequencies?
Answer3: They are 2 input sine wave to the multiplier,
F1 = 100khz
F2 =2khz
Question4:
Why does this make DSBSC signals better for transmission than AM signals?
Answer4: In AM both carrier as well as message signal is transmitted which results in poor
efficiency i.e., 33% but in DSBSC carrier wave is suppressed and the efficiency is almost 100%.
PART B:
Question5:
Why isn’t there any signal out of the Multiplier module when you’re not humming or talking?
Answer5: Becouse there is no message signal sent .
CONCLUSION: