Nautel Explores HD Multiplexing
Radio World Magazine, 04.13.2015
Do broadcasters want or need more FM band capacity, more digital channels?
Nautel is showing a working prototype of a concept called HD Multiplex at the NAB Show, saying the goal is “to foster discussion within the broadcast community” and “determine the appropriate path for further development.”
The company said this technology would enable the placement of up to 15 audio streams or stations within 600 kHz of signal bandwidth or up to nine audio streams in 400 kHz of signal bandwidth.
Nautel’s President/CEO Kevin Rodgers listed possible applications: “A station considering HD conversion could test the waters by leasing an audio stream on the multiplex. AM stations could be moved to the FM band, as proposed by some countries. Netcasters could place their most popular streams on an over-the-air signal. In many cases, this could provide new revenue for broadcasters through leases or ad insertion in the various streams. Further, small markets could have a broad variety of diverse formats served by a single low-cost station.”
Nautel said the technology allows the combination of multiple independent IBOC exgine modulators into one HD PowerBoost crest factor reduction engine, permitting two or more IBOC stations to be amplified using one transmitter and subsequent antenna system. It said this all-digital IBOC configuration is capable of carrying up to three times the standard IBOC content. “The methodology also maintains backward compatibility with existing receivers by ensuring the standard sideband channel separation within the multiplexed signal,” it said in its announcement.
According to Nautel, a transmitter operating in HD Multiplex mode could provide coverage comparable to a higher-powered hybrid analog/digital transmitter. Through modification of the established IBOC crest factor reduction, Nautel’s HD PowerBoost could operate on all of the independent stations transmitted using HD Multiplex.
Nautel’s John Whyte told Radio World, “We present this technology to foster discussion and certainly the regulatory situation in each jurisdiction would need to assess the applicability of the technology.”