Howtosignalprocessing
- What is imaginary signal?
- What are real and complex signals?
- What is imaginary part of FFT?
- Do complex signals exist?
- What is the power of a complex signal?
What is imaginary signal?
Imaginary denotes a signal component that is in quadrature with (i.e. has a 90° phase shift from) the same reference signal. The reference signal can come from a local oscillator. (In DSP or SDR equipment the local oscillator might be a mathematical representation of one, rather than an analog circuit.)
What are real and complex signals?
A real signal at any given time takes its value in the set of real numbers, and a complex signal takes its value in the set of complex numbers.
What is imaginary part of FFT?
The real portion of an FFT result is how much each frequency component resembles a cosine wave, the imaginary component, how much each component resembles a sine wave.
Do complex signals exist?
Also complex signal exists in electronics, where voltage is real component and current is imaginary component of complex signal. Complex signals occur with AC current and plus inductors or capacitors in electronic circuits.
What is the power of a complex signal?
The power of a signal is the sum of the absolute squares of its time-domain samples divided by the signal length, or, equivalently, the square of its RMS level. The function bandpower allows you to estimate signal power in one step.
