Signal

A signal is a means of transmitting information, referring to codes, signs, movements, light, sound, etc. used to convey specific messages or meanings. In a broad sense, it can refer to anything that carries information, making it a widely used term across various fields. Examples include hand signals, radio or television waves, mobile phone signals, beacon signals (light), and people's facial expressions. In communications and electronics, signals are classified according to various criteria.

Classification by continuity:

• Analog signal

• Continuous signal

• Discrete signal

• Digital signal

Classification by periodicity:

• Periodic signal

• Aperiodic signal

Classification by statistical characteristics:

• Deterministic signal

• Random signal

  • Stationary signal

  • Non-stationary signal

Classification by sensory correspondence:

• Audio signal

• Video signal