Drawing One-sided Magnitude Spectrum of Transmitted Signal in dBW
Think about it, your either drawing something in the frequency domain or the time domain. You have time time domain, how do you get to the frequency domain?
The answer is: the Fourier transform.

A carrier has one frequency, a side band has frequency in two places. Since these are symmetrical around the carrier sometimes its advantageous to see only one side.

Since you have not described if you signal is sampled or not it will make a difference on how it is plotted. However, either way a sine wave is just a dirac delta function after you take the Fourier transform

So if you graphed the total power, you would have the amplitude of the carrier with the two side bands x distance away from the carrier with the amplitude of the sine wave being the height of the dirac funuctions of the side bands. 

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