Suppose the normalized pulse shape, hr(t), shown below, is used to generate the pulse train v(t) = unht(t - nT) n=- where {vn} are the transmitted symbols, with each vn selected independently from {-1, +1} with equal probability. The pulse train is then used to modulate the amplitude of a sinusoidal carrier wave, giving the transmitted bandpass signal ve(t) = v(t)/2 cos(27 fet) where fe is the carrier frequency. ht(t) t T T (a) Find a simple mathematical expression for the power spectral density of ve(t). (b) Sketch the PSD of ve(t), assuming fc = 5/T.