This is the fourth in a series of computer science lessons about wireless communication and digital signal processing. In these lessons you’ll learn about the nature of electromagnetic radiation, digital modulation and multiplexing techniques, and how to get the best out of mobile communication systems such as LTE, 5G and WiFi. This lesson introduces the concept of RF modulation, which allows radio waves to carry information. You will learn about the three main types of modulation, namely amplitude modulation, frequency modulation and phase modulation. You will learn how these modulation techniques were developed by pioneers like Guglielmo Marconi, Reginald Fessenden and Edwin Armstrong. You will learn about the advantages and disadvantages of each type of modulation and the impact of each on the bandwidth of a radio signal and its vulnerability to interference. In addition, you will learn about the Fourier transform, a mathematical technique that can be used to decompose a radio signal into its frequency components, allowing to be viewed in the frequency domain with a device known as spectrum analyser.
Chapters:
00:00 Introduction to RF modulation
00:36 Spark gap transmitter
01:28 Guglielmo Marconi
03:16 Reginald Fessenden
03:43 Amplitude modulation
05:20 Fourier transform
06:24 Frequency domain
10:10 Edwin Armstrong
10:35 Frequency modulation
11:30 Phase modulation
11:57 Angle modulation