Digital Radio Processor

http://www.google.co.uk/search?hl=en&q=Digital+Radio+Processor&btnG=Google+Search&meta=

Unfortunately this is one of those open ended questions without any details of what you really want to know.

Despite that I thought I might post a link to a somewhat new spin on radio, a software radio, I think its an interesting concept.

1. radio
2. radios
3. radios

etc., etc....

Yes.

Check out iBiquity Digital. They have a digital radio technology being deployed in the States now. I think TI has the processor chip, with others working on one as well.

Realy cool tech. It allows radio stations to super-impose a digital bit-stream in the unused side-bands of the carrier signal. It provides 7 "layers" of digital content, meaning a radio station can broadcast 2-3 different music formats, and still have room for song info.

It's "digital HD radio" without the monthly fees that the satellite radio guys charge.

Are you wanting to know about Digital signal processors used for audio processing? Or are you wanting to know about Digital Transmission, IBOC?

The Ibiquity link above will tell you about HD Radio, you can buy HD radios for automobiles and the house. HD Radio can theretically contain 8 digital carriers within the analog 10KHz FM bandwidth allocated to a radio station. I do not know of anyone that is currently broadcasting more than HD3. HD1 is usually the digital form of the analog broadcast. HD2,3 and so on are different content that is commercial free programming for atleast 2years. There are many stations across the country that are currently broadcasting HD, I think the number is in the mid 600s in the US.

If you want to know about digital signal processing of audio you may want to check out companies like Orban and Omnia are the two largest manufacturers of processing at transmitter sites.