GFSK problem in link budget analysis

[amr87]

link budget analysis

I am doing a link budget analysis for a direct up-conversion bluetooth transmitter. Sine the bluetooth basic rate uses a GFSK modulation, the flicker noise is an issue. How can we adopt the noise figure definition to include such effect.

After all, I just want to know how to choose the appropriate flicker noise corner and the corresponding white noise level that doesn't degrade the output SNR.
I have read that we can integrate the noise in the band of interest but I think that there is more better ways specially that flicker noise tends to infinity near the DC.

did anyone do something like that or seen something similar in scientific papers even for other narrow-band modulation schemes??

Reagrds

 

[kspalla]

link budget

I guess link budget does not have high priority for flicker noise. It is the over all noise that effect the link budget.

 

[amr87]

link budget + snr

You are right. But the I think we need something that quantify the effect of noise on the degradation of the modulation scheme. Of course, this problem will differ from modulation scheme to another (for example wide band Vs. narrow band).

When we want to obtain the NF of any RF chain, we try to get the SNR at the input and the SNR at the output and use the equation NF=SNR_i/SNR_o. The SNR in the output is determined (for the receiver case for example) by the SNR required for the demodulator to be able to decode the signal with certain BER. This SNR is usually derived for a signal corrupted by white gaussian noise.
So, my question is how can we adopt this method to take into account the flicker noise in the transmitter case.

Regards,