1. Basic concepts
2. Modulation
2.1 Encoding method
2.2 Basic Bandpass Modulation
3. The limit capacity of the channel
two factors
（1）
（2）
Shannon formula
channel multiplexing technology
frequency division multiplexing
It's like you are flying in the sky and I'm running on the ground without interfering with each other
time division multiplexing
So there is statistical time division multiplexing
Time-division multiplexing is fixed to assign a time period to each user, and statistical time-division multiplexing is dynamically allocated on demand, who needs it and who uses it
WDM
code division multiplexing
