Cooperative communication may be more generic. Ad-hoc networks refers to self-organizing wireless networks, in which the wireless hosts also operate as relay stations, to route packets from source to destination. This can happen at layer 2, such as 802.11 operating in ad-hoc mode instead of infrastructure mode, or at layer 3, such as MANET. (In my opinion, MANET uses layer 3 addressing and routing very much as if it were layer 2, but that's another discussion.)
Here's one example of cooperative communication that you might not have thought about:
http://work911.com/communication/coop.htm
But take a look at this, where cooperative communication is used to create antenna diversity effects, with single antenna devices:
I haven't found definite agreement on this, but I would think that even a peer-peer file sharing service such as the original Napster, in which files are transmitted to a destination in chunks, simultaneously by multiple hosts, would also qualify as cooperative communication. Even if not wireless or similar to ad-hoc in purpose.
So in general, I would say that ad-hoc networking is a subset of the techniques covered in the broader area of cooperative communication.
Cooperative communications is basically efficient utilization of communication resources, by allowing nodes or terminals in a communication network to collaborate with each other in information transmission.Ad-hoc networks refers to self-organizing wireless networks, in which the wireless cooperative to achieve high level goals.
So we can say that every cooperative communications networks can be Adhoc networks .