Narrowband Frequency Modulation (NBFM) and Narrowband Phase Modulation (NBPM) take a very similar form to Amplitude Modulation. This video reviews NBFM and NBPM concepts and shows a block diagram model for generating these narrowband signals.
Link to amplitude limiter information: https://www.allaboutcircuits.com/tech...
The information in this video will help you understand concepts found in "Modern Digital and Analog Communication" by B.P. Lathi and Zhi Ding.
You can purchase this textbook here:
https://www.amazon.com/Digital-Commun...