Noise Floor Formula. Thus noise figure is independent of the input signal level. If you do oversampling you have to take that into account as 10log fs2BW.
The noise floor determined by the thermal noise at room temperature expressed in dBm units can be estimated as NFthermal dBm 17410log10 BW. Gain is the system gain. DBm is the power level expressed in decibels relative to one milliwatt.
The thermal noise floor equals 174 dBm in 1 Hz bandwidth and 134 dBm in 10 kHz bandwidth.
Noise_Floor dBm 174 10LOG BW Hz Noise_Figure dB Gain dB Minimum_Detectable_Signal dBm 174 3 dB 10LOGBW Hz Noise_Figure dB Spurious_Free_Dynamic_Range dB ord 2 12 174 IIP2 dBm Noise_Figure dB 10LOGBW Hz Spurious_Free_Dynamic_Range dB ord 3 23 174 IIP3 dBm Noise_Figure. Noise power is based on the thermal noise power at the input of the system along with system gain and noise figure. If we look at the normalized B 1 Hz bandwidth noise floor equation we have. In summary the noise floor is the level of background noise in a signal or the level of noise introduced by the system below which the signal thats being captured cannot be isolated.
