GSM: Modulation Techniques - Overview of the Overview

I was in a training today, kinda joined in the middle of the session and saw that the faculty was about to start with modulation techniques used for digital signals and in GSM. So I though to write it down in my notebook, and sharing with you people.

Modulation: To modulate - To modify. Modifying signal with the reference signal.

I am not sure whether I explained it correctly or not. But here is the Wikipedia link to Modulation thing. Just go though it in case you are not sure about what modulation is.

So, there are many kinds of modulation techniques available today, some of them are:
(1) Amplitude Shift Keying (ASK)
(2) Frequency Shift Keying (FSK)
(3) Phase Shift Keying (PSK)
(4) Gaussian Minimum Shift Keying (GMSK) <-- This is mainly used in current GSM technology.
(5) Quadrature Amplitude Modulation (QAM)
and many others...

(1) Amplitude Shift Keying: Amplitude shift keying is a modulation technique in which the amplitude of the carrier signal is changed based on the information signal.

(2) Frequency Shift Keying: Frequency shift keying is a modulation technique in which the frequency of the carrier signal is changed based on the information signal.

(3) Phase Shift Keying: Phase shift keying is a modulation technique in which the phase of the carrier signal is changed based on the information signal.

Below is the image to explain what about techniques are exactly...

Amplitude Shift Keying, On-Off Keying, and Frequency Shift Keying.

I am still digging into the topic so don't expect this article to be fully correct or something. It may contain some false information which may have slipped away from my mind. If so, please correct me at any wrong point. I'll be greatful..

Keep learning. Keep sharing. Keep improving....
... See yaa in the next... :)

Q5WJMC7JZG6Y