FMeXtra is a deprecated in-band on-channel digital radio broadcasting technology created by Digital Radio Express. It was intended to allow a second all-digital signal to be simulcast with an existing analog FM radio station, offering a less noisy signal that would be particularly useful in urban environments where multipath distortion can seriously degrade analog FM transmissions. It can also support a second all-digital channel at the same frequency, allowing two channels to be broadcast by a single FM station.
FMeXtra is a deprecated in-band on-channel digital radio broadcasting technology created by Digital Radio Express. It was intended to allow a second all-digital signal to be simulcast with an existing analog FM radio station, offering a less noisy signal that would be particularly useful in urban environments where multipath distortion can seriously degrade analog FM transmissions. It can also support a second all-digital channel at the same frequency, allowing two channels to be broadcast by a single FM station.
FMeXtra was one of two competing systems considered by the FCC for standardization in the U.S., and by extension, Canada and Mexico. The other system, HD Radio, could carry up to four signals in a single channel and offer higher quality audio. FMeXtra's appeal was that it could be implemented at relatively low cost, requiring only a single rack mount case added to a radio station's existing equipment and transmitter plant. It required no license, unlike HD Radio which allows one free channel but requires 3% annual royalties for additional channels.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).