Analog vs Digital: Relaying a Signal Through Noise

PhysicsMeasurement & UncertaintyCommunity

Send a sine signal from a source, through noisy relay stations, to a receiver. The analog copy collects new noise on every link. The digital copy is sampled and quantised once, and then each relay regenerates its bits. Change the sampling rate and bit depth to see how quantisation works.

Lesson: Analog noise adds up at every relay and is never removed: after k links the RMS error is about σ·√k. A digital relay only needs to decide whether each bit is 0 or 1, so it rebuilds the bits exactly unless the noise is bigger than half the voltage swing. Digitising adds a fixed quantisation error. That error shrinks by about 6 dB for each extra bit, and more samples per cycle make the staircase follow the wave more closely, but the amount of data grows.

Created by a teacher with Simulic AI and reviewed by the Simulic team.