i dont know a thing about energy spectral densityIs the function f(t) defined anywhere in the problem?
What if f(t) were a constant? Could you calculate the energy spectral density then?
What if f(t) varied with time? Could Rx be described as a frequency-modulated carrier wave?
I have difficulty relating this to Parseval's Theorem for energy spectral density of an aperiodic signal. Given a time domain signal Rx(t) and its Fourier transform Rx(ω), [if the signal is periodic we are dealing with Fourier series], then the energy spectral density is given by the square of the absolute value of the Fourier transform of the time domain signal....find the absolute value of e^jw(t), then square the absolute value...