From Analog to Digital: Signal Simulation

Iraitz — Mon, 08 Sep 2025 11:47:06 +0000

In this project I made a simple simulation of how an analog signal becomes digital. The process has four main steps:

1 ANALOG SIGNAL

I start with a sine wave of 100 Hz.
I use a very small time step, so the signal looks continuous.
This is my reference “analog” signal.

Result: a smooth curve, the original wave.

2 SAMPLING

The analog signal is sampled with different frequencies (Fs = 150, 200, 500, 1000 Hz).

150 Hz (below Nyquist) → the samples are not enough, the signal looks distorted.

200 Hz (at Nyquist) → the minimum frequency to capture the signal, but still not very clear.

500 and 1000 Hz (above Nyquist) → the signal is represented much better.

This shows the Nyquist theorem: the sampling frequency must be at least 2 times the signal frequency.

3 QUANTIZATION

After sampling, the amplitude of each point is mapped to a fixed number of levels.

I tested 8, 16, and 64 levels.

8 levels (3 bits) → very rough signal, steps are big.

16 levels (4 bits) → better, but still visible distortion.

64 levels (6 bits) → the signal looks smooth, very close to the original.

More levels = higher accuracy, but also more bits are needed.

4 SUMMARY

The simulation shows the complete path:

Analog → Sampling → Quantization → Digital Representation

If sampling is too low → aliasing and distortion.

If quantization levels are too low → the signal loses quality.

Higher sampling and more levels → better quality, but more data to store or transmit.

DEV Community: Iraitz