Sources:
- B. P. Lathi & Roger Green. (2018). Chapter 7: Continuous-Time Analysis: The Fourier Transform. Signal Processing and Linear Systems (3rd ed., pp. 736-749). Oxford University Press.
Modulation causes a spectral shift in a signal, enhacing long distance transmission. Broadly speaking, there are two classes of modulation: amplitude (linear) modulation and angle (nonlinear) modulation.
In this section, we shall discuss some practical forms of amplitude modulation, including:
- Double-Sideband, Suppressed-Carrier (DSB-SC) modulation. It is simple and is great for illustrate the idea of amplitude modulation.
- Amplitude Modulation (AM). It's more efficient than DSB-SC, whereas one more condition must be satisfied. Techinically speaking, all 3 methods in this article belong to amplitude modulation. But it is this specific method which people call amplitude modulation (AM).
- Single-Sideband, Suppressed-Carrier (DSB-SC) modulation. It is a simpler form of (DSB-SC) modulation where only one sideband is transmitted.
The term Suppressed-Carrier (SC) comes from the fact that, both DSB and SSB signals only contain the modulated signal, excluding the carrrier signal, maing the carrier being "suppressed".