Time multiplexing

Definition: Time multiplexing is a method of transmitting and receiving two or more independent signals over a common channel path by means of synchronized switches at each end of the transmission line. This way each signal appears on the line only a fraction of time in an alternating pattern. In fNIRS this technique of switching on and off different light sources at fixed intervals avoids the superposition of two sources being detected by a single detector simultaneously. This strategy is commonly employed in fNIRS devices to enable the detector to identify from which emitter the light came from. The temporal resolution of a device is inversely proportional to the number of time multiplexing steps and step width (i.e., the more steps there are, the slower the frequency of acquisition).

Alternative definition:

Synonym: Time division multiplexing

References: DOI: 10.1117/1.nph.8.1.012101; DOI: 10.1201/b17289 (section 7.3.1)

Related terms: Frequency multiplexing