# Effect of number of data segments in Periodogram-based PSD

In Welch or Bartlett method, original signal is divided into L segments, of D overlapping (D=0 in Bartlett method). Then FFT is done for each segment, and the result is the average of all segments' FFTs. Averaging reduces the variance. But apart from this effect, is there anything else to take into account when choosing the number of segments for a given signal?

• @student1: So your total signal is only $32\times 32=1024$ samples? If you only have segments of 32 samples then your resolution of course quite limited. Anyway, you can always zero-pad your data to get more densely spaced FFT values (which of course does not increase resolution, but it gives you a more detailed picture of the spectrum with the given resolution). – Matt L. Aug 25 '14 at 15:46