# MATLAB: Power spectral density of a signal

power spectral density

Hello I have EEG dataset in excel format with time and voltage values.I need to plot the power spectral density of the signal. I have loaded the excel file in Matlab and plotted the voltage vs time values. Now I need to calculate the power spectral density. Generally the frequency range of EEG signals between 0-30 Hz. Since I have only voltage and Time values, I do not know the frequency of my signal. I need to calculate Power spectral density Using FFT. I am including the code in matlab file and time voltage values of the signal in txt file for reference. Please suggest me.
dataset=xlsread('input signal.xlsx','sheet1','A1:B770');t = dataset(:,1);V = dataset(:,2);X=[t V];subplot(2,2,1);plot(X(:,1), X(:,2))xlabel ('time');ylabel('voltage');title('original Signal');

h1=spectrum.welch;set(h1,'Windowname','Hann');Fs=1000;set(h1,'OverlapPercent',66.7);set(h1,'SegmentLength',512);myPsd=psd(h1,X(:,2)-mean(X(:,2)),'Fs',Fs)semilogx(myPsd.Frequencies,myPsd.Data);grid on