Modulation and Decoding in Wi-Fi Transmission

Welcome to the final lecture of this section, where we’ll dive into the concepts of modulation and decoding. These are crucial for understanding how Wi-Fi leverages radio frequencies to transmit and receive data. In this post, I’ll explain what modulation and decoding are, why they’re essential, and how Wi-Fi networks utilize these processes.

Why Modulation and Decoding Matter in Wi-Fi

Wi-Fi uses radio frequency (RF) waves to transmit and receive data. For this to work, modulation and coding processes are employed to encode and decode the data. Modulation is the process of impressing data onto an RF wave, converting it into a signal that can be transmitted. Decoding, on the other hand, is essential for data recovery, ensuring that the received information remains accurate and complete even when transmitted over air.

What is Modulation?

We’ve touched on modulation earlier in this course, but now let’s dig deeper. Modulation is a technique used to “impress” data onto RF waves. When data is applied to an RF wave through modulation, it becomes a signal. This signal can then be transmitted through the wireless network to a receiver. Modulation requires complex techniques to encode data onto RF waves so they can carry information effectively. Once modulated, the radio wave carrying the data is called the “carrier wave,” or simply, the “signal.”

In the IEEE 802.11 standard (used in Wi-Fi), we primarily use two forms of modulation: phase modulation and amplitude modulation. These are categorized as:

Binary Phase Shift Keying (BPSK): A basic modulation method that uses phase changes to encode data.
Quadrature Phase Shift Keying (QPSK): A method that utilizes phase changes but can represent more data per shift than BPSK.
Quadrature Amplitude Modulation (QAM): A combination of phase and amplitude modulation that allows for higher data rates by encoding more data onto each wave.