What is Power Spectral Density (PSD)?

Explains PSD of random signals from both an intuitive and a mathematical perspective. Explains why it is a "density" and shows the link to Autocorrelation with two common examples in digital communications.

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[palisthashrestha]

hating this topic at uni right now but watching your videos is actually making it seem like a fun topic, thank you!

[AM-turc]

A fundamental topic to DSP and Random Processes. Glad to see you cover it so excellently Professor!

[lorenzovezzani]

Thank you for this simple and concise explanation, you were really helpful :)

[timovandrey]

Why did I not find this when I needed it in my studies? lol
Very well explained, way better than my professor back then... Thank you very much!

[colecarroll]

Loved the explanation of units on this video. Im getting my bachelors in electrical engineering and I have a final on this material tomorrow.

[engineershmily]

Why are interested in PSD? Benefit(s)?

[pitmaler]

Thanks for all you videos. I have potential topis for a future video. Perhaps you can elaborate sth. about codebooks with respect to MIMO in 5G. I often read about that. -> the real deployment of MIMO in practical systems
(How many are there? Are they in DL and UL? do you have it at every BS and every UE? What means the terms layer and Precoding Matrix Indicator PMI?)
Thank you very much.

[yepitsodex]

Wait, how is the integral of the input signal squared in joules at ~5:50??? The integral of the 'value' squared times seconds = N*m means the signal x(t) has to be in units of sqrt(m*N/s)

[knutlohmann]

You say we cannot take the FT of a stationary process because the signal is all over the time (up to infinity I assume). But, your voice recordings are limited. Isn't that a contradictory?

[stellatauer]

An interesting topic would surely be an analysis of the voice charts. What influence has a change of amplitude, phase and frequency? How do humans perceive these changes?
What makes our voices different from each other? Is it just a change in these 3 parameters? Can we regenerate others voices when we have these 3 parameters? Thanks a lot.

[tuongnguyen]

Can we measure this by oscilloscope ? or it just a mathematical concept ?

[dalizjuarez]

so cool video but, there is a specific bibliography for this ?

[engineerahmed]

Can u plz doa simple example of "9 sine wave summed signal"
1st split final signal into its consituent 9 sine waves using FFT
Then group them by freq into 3 freq bands
Then obtain grms of each band ...sq that & plot psd points on psd plot

[ang]

Assume I have a perfect sequence of real Gaussian intensity pulses in time domain. I seem to know that if we measure this sequence with a spectrum analyzer we get a set of delta functions (lines) under a Gaussian envelope. This set of lines is a spectral power, but is it the power spectral density (PSD function in frequency domain)?

[georges]

I used PSD to analyze the dynamics of ion channels in mammalian cellular membranes.
The corner frequencies which relate to the opening and closing rates of the ion channels can be estimated.

[lucidasser]

Thanks, I cannot found the summary sheet about that topic on your page.

[jasminnadic]

The voice recordings at the beginning, is the amplitude of these signals proporuonal to the sound level (loudness)?

[jerrythomas]

Thank you sir. Can you make videos on channel coding (LDPC codes), different types of channels, machine learning

[mejoe]

1:51 Is there a mistake here? You say "you cant take the Fourier transform of a stationary process" Did you mean non-stationary?

[louisli]

Does it mean that in digital communications, we usually to use PSD to describe the frequency characteristics of the digital signal? Such as bandwidth usage? Many thanks