Frequency-Division Multiplexing
Aims
(1) To enhance the understanding of the principles and methods in the system analysis in the
frequency domain.
(2) To understand the physics significance of the modulation and demodulation, and enhance the
understanding of the principles and methods in the amplitude modulation and demodulation
for continuous-time signals.
(3) To foster students’ abilities in applying the theories and techniques comprehensively in
solving real problems in the engineering practice.
Key Concepts and Points
Modulation and demodulation, the principles of frequency-division multiplexing, analysis of 信
号signals in the time and frequency domains.
Simulation Contents
1. Amplitude modulation of a music signal.
Using the function waveread() in the MATLAB to open file “I_Swear_1_x2_up.wav.” Using
the methods we learned during the classes, modulate the music signal in the file to the
frequency band centered at
=20000Hz
c
f
. Sketch that block diagram demonstrating the
modulation procedure.
2. Demodulation of frequency-division multiplexed signals
Multiplexing is a method in which a number of independent signals can be transmitted in the
same communication channel. For example, to transmit several different voice signals using the
same radio frequency channel, we may modulate the voice signals to different frequency bands.
