Two topics of interest at this year NAB Show 2018 Broadcast Engineering and Information Technology Conference were the state of HD Radio and the results of recent testing -- and a related demonstration -- of all-digital sidebands in a multiplex.
The first HD Radio transmission occurred in 1992 from WILL(FM) in Champaign, Ill. In 2018, according to Xperi Digital, over 50% of new cars are equipped with HD Radio receivers. Fresh from the Nautel Users Group gathering, Sales Manager Central USA Jeff Welton shared some tips and suggestions for HD Radio engineers, and advice. “I tell people every HD Radio install is situational, there is no one right way to do an install.”
Nautel, Xperi, NAB Pilot and Beasley Broadcasting are conducting the broadcast demo during the show using all-digital sidebands in a multiplex on that broadcaster’s Las Vegas station, KKLZ.
The experimental demo shows the ability to transmit multiple IBOC sidebands within a station’s signal, using Nautel HD Multiplex. According to an announcement, the demo provides two independent IBOC sidebands on each side of KKLZ’s regularly programmed analog FM carrier; it encompasses several minute-long loops of audio content, intentionally placed on the “even” dial positions surrounding the station, heard at 96.3 MHz. The four digital sidebands are located at 96.0, 96.2, 96.4 and 96.6 MHz, frequencies that are not normally associated with standard FM radio stations in the U.S., and provide capacity for up to 12 HD Radio audio services in addition to the FM carrier. The organizers said Beasley is suspending its regular HD Radio programming during NAB Show exhibit hall hours to support the live demonstration.
The demo is a follow-up to all-digital FM radio tests earlier in 2018 at KKLZ, when a variety of test signals, including a 600 kHz-wide HD Multiplex signal, consisting of three pairs of IBOC sidebands, were transmitted during overnight hours. According to the organizers, the test successfully demonstrated over-the-air reception of 15 separate audio services.
NAB's David Layer presented results. “We see the future coming; there’s going to be autonomous vehicles," he said, which will present a new range of possible applications related to HD Radio's data capabilities. "We believe all-digital radio may be a player in that space. We think it’s time to start thinking about all-digital.” The test is being conducted with commercially available automobile receivers that are capable of receiving the digital transmissions.
NAB Show attendees will be able listen to the test at the Pilot section at the Futures Park in the North Hall.