Howtosignalprocessing
- What are the types of input signals?
- How do the output signals depend on the frequencies of the input signal?
- How do you find impulse response from input and output?
- How do you know if a signal is time-invariant?
What are the types of input signals?
The commonly use test input signals are impulse, step, ramp, acceleration and sinusoidal signals. A signal of very large magnitude which is available for very short duration is called impulse signal. Ideal impulse signal is a signal with infinite magnitude and zero duration but with an area of A.
How do the output signals depend on the frequencies of the input signal?
For each value of frequency the function produces a complex amplitude, which is then multiplied by the input signal to give the output of the system. This results in the amplitude being scaled by some factor and the phase being shifted.
How do you find impulse response from input and output?
Given the system equation, you can find the impulse response just by feeding x[n] = δ[n] into the system. If the system is linear and time-invariant (terms we'll define later), then you can use the impulse response to find the output for any input, using a method called convolution that we'll learn in two weeks.
How do you know if a signal is time-invariant?
One test to verify time invariance/variance property of a system is to shift the response of the system to an input signal and apply a shifted input, to the same system and compare the two waveforms, so obtained. If the system is time invariant, the two waveforms will match when the input and output shifts match.
