informationssignalen

Informationssignalen is a term used in information and communication theory to denote the part of a signal that conveys meaningful information, as opposed to the carrier waveform, noise, or distortion. In communications engineering, the information signal is the modulating signal that is transmitted or processed to convey message content. It can be analog (continuous-valued, e.g., speech) or digital (discrete-valued, e.g., a bit stream). In a transmission system, the information signal is used to modulate a carrier so that its content appears in the transmitted waveform; at the receiver, demodulation recovers the information signal for interpretation.

In signal processing, the information signal is often treated as a random process with statistical properties. Shannon information theory measures the rate at which information can be transmitted over a channel, with the information signal representing the source of data to be conveyed. The quality of reception is affected by noise and distortion, which degrade the information signal and influence metrics such as bit error rate and channel capacity.

Common representations include time-domain signals s(t) and their frequency-domain spectra. The information signal's bandwidth, power, and modulation scheme determine the system’s performance and efficiency. Digital information signals enable error correction, compression, and multiplexing.

Examples include voice signals, text data, images, and video streams. Applications range from telephone and radio to modern data networks and digital audio/video systems.