Time/Frequency are interrelated parameter of a signal and both representations are two views of a same signal. Most of the time in practice, the signal measuring, is a
function of time. That is TIME-DOMAIN. In other words, when we plot the signal one of the axes is
time (independent variable), and the other (dependent variable) is usually the
amplitude. When we plot time-domain signals, we obtain a

**time-amplitude representation**of the signal.
This representation is not always the best
representation of the signal for most signal processing related applications.
In many cases, the most distinguished information is hidden in the frequency
content of the signal. The

**frequency SPECTRUM**of a signal is basically the frequency components (spectral components) of that signal. The frequency spectrum of a signal shows what frequencies exist in the signal. The below represents a signal in time domain and frequency domain.
Demo :

In the above demo :

Red Color --- TIME DOMAIN SIGNAL

Blue Color --- FREQUENCY DOMAIN SIGNAL

**MATLAB Code:**clear all; clc; close all; f=50; A=5; Fs=f*100; Ts=1/Fs; t=0:Ts:10/f; x=A*sin(2*pi*f*t); x1=A*sin(2*pi*(f+50)*t); x2=A*sin(2*pi*(f+250)*t); x=x+x1+x2; % Creating Hybrid signal which will have more than 1 frequency. plot(x) F=fft(x); figure N=Fs/length(F); baxis=(1:N:N*(length(x)/2-1)); plot(baxis,real(F(1:length(F)/2)))

//Most of the signals in practice, are TIME-DOMAIN signals in their raw format.// Not correct. Time/Frequency are interrelated parameter of a signal and both representations are two views of a same signal. In ideal case, Square waves should consist of infinite frequencies.

ReplyDeleteYes, Thank you for the input.

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