The purpose of this exercise is to demonstrate the properties of SSB modulation. Develop a computer program to generate both upper-side band and lower-side band SSB signals and display both the time-domain signals and the amplitude spectra of these signals. Assume the message signal 

m(t) = 2 cos (2πf_mt) + cos (4πf_mt)

Select both f_m and f_c  so that both the time and frequency axes can be easily calibrated. Plot the envelope of the SSB signals, and show that both the upper-side band and the lower-side band SSB signals have the same envelope. Use the FFT algorithm to generate the amplitude spectrum for both the upper-side band and the lower-side band SSB signal.