Any in-band digital solution has no choice but harm the host analog signal and/or the adjacents.
The best solution would have been to have every analog allocation "mapped" to another frequency offset by a specific amount,
and in "new" spectrum.
AM MW's digital component should have been mapped to 2.0 to 3.8 mhz, the FM broadcast band should
have been mapped into the 45 mhz range, or some other under-utilized spectrum.
I can't believe the ITU hasn't already made such a decision for worldwide application.
It's not as though digital audio transmission is so new that the ITU couldn't have already made some allocations.
Perhaps it's just another example of pretending that competition will always bring the best result.
Many times, it can be proven that a cooperative solution does the most good.
What we got here in the US was the most divisive possible solution, that permitted the greatest amount of disruption,
mostly to the benefit of corporations over natural persons.
I still miss how clean and uncluttered FM used to sound, particularly in the car.
Where I live, FM constantly has spits and flutters as airplane reflections cause cancellation, allowing the FM iboc sideband
noise to intrude, making city grade signals sound like semi-dx did 30 years ago.
I did notice the cancellation noises/etc when I moved near the airport, before iboc came along, but it wasn't obnoxious.
I actually get a lot less noise on AM than FM. And I'm using a mono-only Motorola receiver in the car.
I used to be able to listen to many signals across the lake, from Michigan.
Not that I wanted to very much, but now it's hard to listen to signals from 10 miles away.
Oh, I can listen, but I choose not to listen to something where I have to hear so much extraneous noise.
If I wanted so much noise, I could be listening to shortwave instead, if there were anything left to listen to.
That's unacceptable.