Signal, as a waveform, is the carrier of data. By alternating amplitude, frequency, phase, or any combination of them, the modulation process synthesizes the signal (as the carrier wave) and the data (as an input wave) and generates the modulated result. Modulation can be analog or digital.

Digital Modulation

There are many types of digital modulation techniques, for example:

• ASK – Amplitude Shift Keying
• FSK – Frequency Shift Keying
• PSK – Phase Shift Keying

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References

• HOW DOES MODULATION WORK?
• Carrier wave
• Data vs Signal | Difference between Data and Signal
• Carrier-sense multiple access
• Carrier-sense multiple access with collision avoidance
• Carrier-sense multiple access with collision detection
• Digital Modulation Techniques