Dear reltol1,
Some researchers prefer to calculate the dominant noises that affect the circuits, whereas some analyse the simulation and cancel the respective function of the circult to obtain the noise figure. This noise figure can be further analysed for possible dominant noises.
However, noises have been studied over the past 5 decades. Literature about noises has been so well-documented that experienced researchers and engineers, at the snap of the finger, can tell what noise is present in which circuit, in PCB or IC, in low power or high power, in RFIC or baseband circuit, and so. It's like common-sense tells us what we already have realised.
In any circuits, irregardless Analog or Digital, you may study the following noises:
1. 1/f or Pink Noise
2. Johnsson or Thermal Noise
3. Shot Noise
4. Additive White Gaussian Noise (AWGN) or commonly known as White Noise
5. Flicker Noise or Recombination Noise in BJTs only
6. Switching Noise (commonly known as AC Voltage Fluctuations)
7. Crosstalks
8. Signal Return Noise
9. IR Drop
10. LR Drop
11. RC Loss or High-Frequency Attenuation or LPF Effect
12. LC Loss
13. EMI
14. Main or 50/60Hz Noise
15. All leakages (flux and current) are noises
Some of these are voltage-variable noises whereas some are independent noises.
There are also timing noises:
1. Jitter
2. Skew
3. Inter-symbol Inteferences (ISI)
All these timing noises have phase differences to that of your signal, thus the signal can suffer from additive or subtractive amplitude change. If the signal suffers from a noise with 180 phase difference, the signal can be almost cancelled.
IC Design Enr.
PhD (Imperial College London)
Analog Devices Plc. (Ireland)