Definition: baseband

Electronic data in their original form. Baseband refers to analog or digital data before being intermixed with other data. See multiplexing and modulation.

For Example
The output of an analog microphone is baseband. When an FM station's carrier frequency is stripped away in the radio (demodulated), the original audio signal that you hear is the baseband signal. See frequency modulation.

Ethernet transmission is considered baseband, because signals are not intermixed and occupy the full bandwidth of the line. In fact, "base" is part of the Ethernet version name (see 10Base-T and 100Base-T).

When a compressed digital audio signal such as MP3 is transcoded to another format, it is decompressed back to the original bit rate (the baseband signal) before it is compressed into the new format (for a specific example, see aptX). See baseband processor.

Baseband Video

In this cable TV set-top box manual, "baseband video" refers to the composite video signal from an analog VCR or camcorder, which comprises only video frames not intermixed with the audio. See composite video and carrier frequency.