t=0:1:65536;
    Fs=1e6;
    Data=cos(2*pi*200e3*t/Fs);
    FFT_L = 2^(floor(log2(length(Data))));
    FFT_Data = Data(1:FFT_L);
    FFT_Data_Wn = (hanning(FFT_L))';
    FFT_Out = fft(FFT_Data_Wn.*FFT_Data,FFT_L);
    figure;
    fig_x = linspace(-Fs/2,Fs/2,FFT_L);
    fig_y = 10*log10(abs([FFT_Out(FFT_L/2+1:end),FFT_Out(1:FFT_L/2)]/FFT_L).^2);
    plot(fig_x,fig_y,'b');
    axis([-Fs/2,Fs/2,-100,10]);
    title('PSD of input Data');
    xlabel('Frequency');
    ylabel('Power(dB)');