![]() ![]() But that's totally irrelevant to your observation – your measurement doesn't go into the terahertzes. However, it's not really white – the power density decreases at very high frequencies. Example: the thermal noise you can measure over a resistor is the classical example of white Gaussian noise in systems. Everything else is physically impossible – but rarely matters. Notice that you're never dealing with a truly white Gaussian noise in continuous-time systems (luckily for the universe, I might add) it's always approximately white for some bandwidth. The total of power of additive white Gaussian noise is infinity, what does this mean? Is it reasonable to assume that the noise added to the signal have an infinite power? sine waves, have power at a single frequency everything else has a "power distributed over frequencies".) (This is kind of an important distinction to make – only infinitely long periodic signals, e.g. The Power Spectral Density is constant – a single frequency doesn't have any power it has a "power per bandwidth"! To arrive at a power, you need to integrate the density over a non-zero mass of frequencies. No, BUT: You mean the right thing, you just say it wrongly: If I want to know the power of a certain frequency in the signal (not in a range of frequencies), can we say that the power of each frequency in the signal is exactly No/2? ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |