“Single-Frequency Networks for HD Radio”

Learn the parameters for a hybrid FM+IBOC booster installation that minimizes on-channel interference
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Nautel Ltd. Research Engineer Philipp Schmid will talk at the NAB Show about planning parameters required for a hybrid FM+IBOC booster installation that minimizes on-channel interference.

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The topic should be of interest to FM broadcast engineers looking to improve or expand their station signal coverage through the use of single-frequency networks as well as technology “visionaries” looking to see what is possible with HD Radio technology down the road.

“With careful coverage planning,” Schmid told us, “HD Radio SFNs allow seamless coverage between adjacent on-channel transmissions, providing clear audio in the transition region. Analog FM transmission can at best minimize audible interference in the transition region. HD Radio SFNs can be used to fill-in terrain obstruction today, and in the future can be deployed in cell-based configurations once all-digital transmission is adopted.”

Schmid said he will present an HD Radio SFN implementation that can also solve the diversity delay problem that causes listener annoyance when blending between misaligned FM and HD-1 audio streams.

“We control the HD-1 audio throughput delay from the studio to the RF transmission waveform [see image] in order to meet very tight SFN timing requirements. As long as the FM throughput delay does not vary, the diversity delay can be dialed in very precisely using the HD-1 audio as a reference, even if the station has no intention of operating in an SFN configuration at this time.”

His session will be held Sunday afternoon during the Broadcast Engineering and Information Technology Conference.

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