In a literature I face with this input and power spectral density (PSD) $$x(t)=s(t)+n(t)=A\cos\left(\omega_c t +\phi\right) + n(t)$$
first I want to know
- How can we find PSD of $\cos\left(\omega_c t +\phi\right)$?(I have found the autocorrelation function of $\cos\left(\omega_c t +\phi\right)$ but when I apply the PSD with Fourier transform it doesn't return the same result as the figure)
- Why do we divided PSD of $\cos\left(\omega_c t +\phi\right)$ by $R_L$?
- What is a bandpass filter's transfer function in time and frequency? And how can we find PSD of a bandpass?
Sorry for the simple question but I think I got confusing.