Hi,
in Ken's paper "Modeling Jitter in PLL-based frequency synthesizers"  there is the matlab script  (listing 9) for computing phase noise PSD by Welch's method. But the function "psd" itself is not a matlab built-in function, isnt it?  :'( I tried it, and matlab did not find such function.

I found on MathWorks online documentation explanation about "pwelch" function doing the same thing, but it is a part of their Signal Processing Toolbox, and i currently can not use it.

There is another script (matlab function) that can i use for free?

Thank you for your help,
Irvin.

[quote author=Irvin73  link=1076508979/0#0 date=1076508979]  Hi,
in Ken's paper "Modeling Jitter in PLL-based frequency synthesizers"  there is the matlab script  (listing 9) for computing phase noise PSD by Welch's method. But the function "psd" itself is not a matlab built-in function, isnt it?  :'( I tried it, and matlab did not find such function.

I found on MathWorks online documentation explanation about "pwelch" function doing the same thing, but it is a part of their Signal Processing Toolbox, and i currently can not use it.

There is another script (matlab function) that can i use for free?

Thank you for your help,
Irvin.
[/quote]


gnu-octave works fine & it is free. If you use it on linux, install the octave-forge package which provides the pwelch() function.