I'm trying to understand the periodogram function. If I take the periodogram of a sinusoid, the power of the positive and negative frequency components are -6 dB, whereas I would expect them to be -3 dB (the power is evenly split between the positive and negative frequency).
Similarly, if I perform the multiplication of two sinusoids, the power of the resulting frequency components are -12 dB, whereas I would expect them to be -6 dB.
Is there something wrong with my code or with my understanding?
Thanks for the help.
clear all; close all; clc
fs = 10e3;
fc = 500;
t = linspace(0,1,fs);
y = sin(2*pi*fc.*t);
[P,F] = periodogram(y,,length(y),fs,'power','centered');
xlabel('Freq. in Hz')