Amplitude Modulation, Demodulation, and Carrier Recovery

Abstract

In this chapter we will learn about amplitude modulation (AM) of signals: double side-band with (large) carrier (DSB-LC) and with suppressed carrier (DSB-SC), and single side-band (SSB) with only left (LSB) or only right (USB) side-band. We will become familiar with Hilbert transform role in amplitude modulation and demodulation and with importance of carrier recovery (synchronization) in amplitude demodulation. In the second part of the chapter we will analyze different non-adaptive carrier recovery methods. We will discuss also two adaptive carrier synchronization techniques: phase locked loop (PLL) and Costas loop.