AM IBOC System Mods Coming?
by Leslie Stimson, 03.24.2010
In my previous edition I wrote about the inclusion of AM in upcoming HD Radio portables. I suspect system modifications from iBiquity are helping that development along.
Though company executive Bob Struble told me the technology developer had nothing just yet to announce, he did mention some sort of planned software upgrade the company is working on to optimize AM reception. I've written about this off and on since AMs were allowed to power up their IBOC at night in 2007, and now the company seems to have made some headway.
I noticed that Jeff Detweiler will speak at the NAB Show about upcoming AM HD Radio exciter software improvements providing new features.
Those features include, among other things, a way to allow the AM analog signal "to be restored to 10 kHz bandwidth while providing stereo digital in a single stream configuration which is backwardly compatible with existing receivers." Other updates include AM HD Radio data support for synchronizing audio and data applications and improved time synchronization between audio and PSD to improve music tagging applications.
Another new PSD support feature will sustain station logo and album art images, he said.
Get a sneak look at what Detweiler will talk about here, in the digital edition of the newest Radio World.
| COMMENTS (7) | | hwh - 07/23/2010 | | Good idea, this analog mode with station ID left on the digital part. You can't hope to beat 10 kHz AM with 32 kbps digital. |
| | Anonymous - 04/08/2010 | | I've experienced more distortion in moderate bandwidth radios when transmitting 10khz audio. The station sounds better when you cut the Optimod back to 5 or 6 khz. No one has called to complain about 5KHZ analog audio bandwidth.
Personally I would like to get all 50kbps of data on the digital channel for audio and let the data pass starve. 32kbps is a bit rough on audio just yet. I haven't tried using Neural processing on the digital channel yet to see if it can help the grunge of the HD coder. I suspect it will.
I have to agree with the thought on using C-Quam at night and HD during the day.
Can anyone get Ibiquity to make the decoder chips with a wider analog reception mode? The crappy sound in analog is artificial and annoying. |
| | Anonymous - 03/25/2010 | | The only way to solve thee digital problems associated with AM radio is to transmit digital components that cancel each other out during transmit. Selective fading will still cause massive issues that will be very difficult to overcome. Essentially, any changed made will improve local reception but long distance reception will still suffer. |
| | Anonymous - 03/25/2010 | | The backawards compatibility that I would like is the ability to switch the iBiquity exciters over to provide digitized version of analog C-Quam AM stereo at night, yet maintain only enough digital to provide Station ID. This would eliminate the night time problems, give stations high quality audio at night for hundreds of miles without disrupting their neighbors on the dial. Also, if all AM stations used GPS to synchronize, there would be no platform motion or hetrodyning, providing decent night time audio.
Now if they would just get some AM stations to offer some unique (XM-like) LOCAL musical programming instead of talk, that would be great. A lot of wishing and hoping, but wouldn't it be great if they did do this? |
| | Anonymous - 03/25/2010 | | James, you have yet to prove your "rating theory" from the other post regarding people tuning out. Still waiting... |
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