Amplitude noise and Phase noise?

[GDF]

what does awgn do to phase noise

I have several questions about noise in communication system, anyboday
can help me?

1)
In communication system, thermal noise is amplitude noise?phase noise?
or both? How do I look it as?

2)
What kind of physical noise like thermal noise, shot noise is modeled by
AWGN?

3)
In addition to AWGN, what kind of noise is often modeled in communication
system?

4)
Do we look the quantization noise as same as thermal noise in communication
system?

Thanks,

 

[dinolin]

thermal noise is AWGN.
Pink noise is used in audio.
quantization noise is limited in amplitude. Not as same as thermal noise.

I have several questions about noise in communication system, anyboday
can help me?

1)
In communication system, thermal noise is amplitude noise?phase noise?
or both? How do I look it as?

2)
What kind of physical noise like thermal noise, shot noise is modeled by
AWGN?

3)
In addition to AWGN, what kind of noise is often modeled in communication
system?

4)
Do we look the quantization noise as same as thermal noise in communication
system?

Thanks,

 

[oriental_adam]

Clarify the definitions of thermal noise, amplitude noise, phase noise quantization noise...

You will get the answers!

 

[GDF]

thanks,
I have another question, how I generate thermal noise and quantization noise
in time domain by matlab?
For example I have a noise power spectral density of thermal noise is abs(Sn),
Sn=1e-18/Hz. How to do this calculation?

By the way, how do I add quantization noise in the simulation of demodulation?
What's the difference when the two kinds of noise be simulated?

Regards,

 

[SkyHigh]

GDF,

I have several questions about noise in communication system, anyboday
can help me?
1)
In communication system, thermal noise is amplitude noise?phase noise?
or both? How do I look it as?
2)
What kind of physical noise like thermal noise, shot noise is modeled by
AWGN?
3)
In addition to AWGN, what kind of noise is often modeled in communication
system?
4)
Do we look the quantization noise as same as thermal noise in communication
system?
Thanks,

1.
Thermal noise "floored" the entire EM spectrum, i.e. all frequencies, with an average of 300mVrms, thus causes fluctuation in signal amplitude, hence an amplitude noise.
Thermal noise is not a phase noise.

2. AWGN comprises both thermal noise and shot noise. AWGN models both these noises.

3. Thermal noise dominates greater power density than shot noise in a physical transmission largely dominated by R and L. Therefore in communication system, channel noise is modelled by thermal noise as AWGN.

4. Quantisation noise is conversion error in dB (with respect to LSB). It is not thermal noise.

Added after 11 minutes:

thanks,
I have another question, how I generate thermal noise and quantization noise
in time domain by matlab?
For example I have a noise power spectral density of thermal noise is abs(Sn),
Sn=1e-18/Hz. How to do this calculation?

By the way, how do I add quantization noise in the simulation of demodulation?
What's the difference when the two kinds of noise be simulated?

Regards,

1. Simon Haykin (PhD Birmingham, UK) has written some books on Adaptive Signal Processing and Digital Modulation, Space-Time Spectral Analysis etc.
2. Peter Grant (PhD Edinburgh, UK) has also written books on Digital Signal Processing, Digital Modultion etc.
3. Hanzo (PhD Southampton UK) as well.
4. John Proakis (Boston)

Their books are likely to have Matlab examples on class problem/assignment what you are working with.

I am very sure because I have seen one of these books or their companion guides offer Mathlab examples.

 

[OMEsystem]

Hi SkyHigh

I have several questions, please help me to clarify this.
1. Thermal noise is a kind of noise on amplitude or phase domain? or both?
I mean does thermal noise affect the phase of a signal?
2. As above, quantization noise is amplitude noise or phase noise or both?
3. How do we look thermal noise and phase noise generated by LO ?
What's their difference?

Thanks a lot,

 

[dspman]

Hi SkyHigh

I have several questions, please help me to clarify this.
1. Thermal noise is a kind of noise on amplitude or phase domain? or both?
I mean does thermal noise affect the phase of a signal?
2. As above, quantization noise is amplitude noise or phase noise or both?
3. How do we look thermal noise and phase noise generated by LO ?
What's their difference?

Thanks a lot,

hi

1- YES thermal noise also effects phase as well as amplitude. it can cause many problems in some comunication systems.
2- Quantization noise also affects both amplitude and phase!!
this type of noise can be modeled as AWGN, in tip toe calculations but the more realestic way is to model it as it is. I mean you have to generate the signals then quantize them and after that process the quantized signal.
3- the termal noise and phase noise of the LO have effects on your signal when it goes throw mixers. so you have to mention them carefully. some times and in some systems they are buttle neck! so they have to be modeled carefully.

yours,