RF signal identification algorithms
Plenty! In fact, since the mid-1970s, people in security have been working on automatic transmission classification.
It's a hard problem, and you logically can't detect all transmission schemes, but it's something that's being sold as service and as product, especially for government (and three-letter government agencies).

These guys, for example, focus on HF/VHF/UHF comms, and I've seen the list of classifiable transmission schemes they had for a public demo. It's long.

Now, what these recognize are just common standards (in Ham Radio, that would be called modes),  and they are specific to one greater usage scenario (security-relevant communication). 

There's a lot of underlying algorithms to automatically classify the number of observed channels, bandwidths, symbol rates, constellations, spreading, scramblers, error-correction codes, frame lengths, synchronization preambles.... but even listing these would take a book.

I can point you to what a student did during Google summer of code: It's gr-inspector, a GNU Radio-based signal detection and classification program.



It's pretty generic in that it detects bands with power in them (which is no good for spread-spectrum systems, but for anything else it's a viable approach), and it gets pretty specific once you have an OFDM signal in there. Part of his job was writing a classifier just to get OFDM parameters: carriers, spacing, length of cyclic prefix. That took someone who was dangerously close to being a M.Sc. in communications engineering nearly 3 months. You can imagine how much work it is writing a set of classifiers for all useful transmission schemes!

You might be interested in the two papers he cites in his blogpost I linked to above; and especially their references.