Extraction of analog useful signal from noisy signal

The signal processing allows extraction of useful information from noisy signal. We must distinguish between the signal, which carries the useful information and the noise which interferes with it. Filtering a noisy signal consists to suppress or attenuate undesired components to improve the quality of the received signal. Analog filtering uses passive (resistor, capacitor, inductor) or active components like bipolar transistor or operational amplifier, while digital filtering (discrete signals) is performed from a programmable integrated structure. Adaptive filtering involves adjusting the filter in real-time based on the signal and noise, which can be especially effective when the noise varies. As long as the changes brought by noise (random signal) are unknown, their amplitudes are random variables. Random (i.e., non-deterministic) signals cannot be completely predicted until they have been observed. In this paper, we design and simulate an analog noisy signal. Using electronics schemes we show how to generate noisy signal and how to extract useful signal from it.