[SOLVED] infomation in time domain and in frequency domain

[shitansh]

Hi,

I am new to DSP and trying to learn it. Initially I have doubt about time domain and frequency domain, means what kind of information is there in time domain and in frequency domain of same signal say Y = A sin(2Π/t);

I tried to find and got one use full like, if any one can put more light on this
**broken link removed**

Any basic information about time domain and frequency domain will be appreciated.

Can any one tells basic of signal information in time domain and in frequency domain.

Thanks,
Shitansh Vaghela

 

[shhrikant1]

Hi,

Even I am new to DSP ,
Buts as per my understanding , there is no physical meaning of frequency domain of a signal, its just a domain which we use for the simplicity of processing a signal & for the ease of mathematical calculation.
Once we have a signal in time domain , we convert it Frequency domain through Fourier transform , then do the calculation part or processing , then convert it back to time domain by inverse Fourier transform.

You might be knowing this, just in case

regards,
Shrikant

 

[shitansh]

No its not like that.

For example we had one signal in space domain then that signal has information about phase and angle but as long as we convert it into frequency domain by DFT then that data in frequency domain has different information that it had in space domain and we can easily manipulate these information in frequency domain and then again converting it back to space domain to had polar and phase information.

This is what I understood let some one put some light on this.

Thanks
Shitansh Vaghela

 

[Ahmed Alaa]

Time domain: A temporal signal variation; as time proceeds, the amplitude of a signal changes, at t = 0 your signal y = sin() is 0, at time t = 0.25 it is 1 and so on.

Frequency domain: Represents what harmonics are in the signal; the whole sine I was talking about in time domain and measuring its amplitude at different times can be represented in the freq domain by a single impulse, the location of this impulse on the frequency axis -say fo- represents how much this sine wave changes over time !

Sin(Wot) and Sin(2Wot) in frequency domain are delta(W-Wo) and delta(W-2Wo).

Conversion from one domain to another is done by fourier transform,

 

[permute]

to the OP,

different applications will give you more context.

for example, audio.
in audio, the human ear can hear around 20hz to 20khz. audio processing can be done for various things. BUT, the human ear will preceive any "non harmonic" sounds as unnatural. (further time-frequency analysis is interesting for audio, particularly in "attack/decay" patterns)

non-harmonic sounds might be a product of a system clock accidently mixing into the actual audio.

For Radio, QAM and OFDM are good subjects to see why both time and frequency domain information is useful.