What's the application of PSD and ESD?

[magnetra]

I've been going throught the concepts of Energy Spectrum Density and Power Spectrum Density. It seems that ESD is used incase of energy type signals and PSD is used for power type signals. Given that all practical signals are of energy type, ESD should have been used for their analysis. But I see that in almost all cases of communication signal analysis, PSD is used. Like we discuss about PSD of line coding wave forms, PSD of band pass signals? So where does ESD stand? Why are we using PSD for practical signals??

M

 

[opterix]

esd vs psd

Maybe its cause the ESD needs to integrate over all the time. All practical signals are ESD, but its impractical to use if we have random signals, and considering that we have to make a digital treatment: its easy to implement algorithms over a finite time...

 

[alizadeh_m]

psd and esd signals

The stochastic processes that we encounter are always considered stationary, and it can be proved that all stationary processes are of the power type. Therefore, the PSD is common.