fourier transform to analyses voice signal

I want to learn the concept how we analyses the signal between the transmitter and receiver

AM TRANSMITTER (this is only paper work )

modulations type am modulations
frequency range 1mhz
voltage supply 12v
transmitting distance 80m-100m
audio frequency 20hz-20khz
antenna
low level modulated with linear amplifier

i need following circuit to make transmitter
audio amplifier circuit
Oscillator circuit
RF amplifier circuit
microphone

i need circuit that amplify the signal of mics
i know to make amplifier circuit
transistor NPN, PNP transistor
mode ce, cb, ce
class A, B, C amplifier

for design audio amplifier we select following parameters
audio source -microphone
transistor npn transistor
mode common emitter
class class A power amplifier

transistor ratings
collector emitter voltage=30v
collector base voltage=60v
emitter base voltage=5v

collector current=800mA
power=500mW

microphone ratings
frequency response 20khz
impedance 2k ohms


In my course i have subject basic electronics so i have used theory in practical way I have assemble some component and made am transmitter now I have another subject signal and system I want learn in practical way so I want analyses voice signal of am transmitter rf signal can be represent in term of frequency and time and I have option I can use fourier transform z transform laplace transform
I am confused don't know how to analyses signal I don't want to whole solutaion i just want to hint how i can analyses the signal