The paper is a survey of the field on cooperative networks. Surprisingly enough, it is a short survey, meaning the field is still very new. It has only 11 references. This survey cites the origin of cooperative network in the paper of Cover and El-Gamal (capacity theorems for the relay channel, IEEE Trans. Info Theory, 1979).
The survey categorizes four different types of cooperation: detectand forward; amplify and forward; decode and forward; coded cooperation.
- The first one pairs nodes in a pair, and each partner's node attempts to detect the partner's bits and then retransmits the detected bits.
- Amplify and forward is more of an analog version of the first one: the partner receives a signal, and amplifies it. The receiver then decodes based on the signal received fromt the source and from the source's partner.
- Decode and forward is a variation of the first one, in which the partner encodes the packet from the source differently, so that the receiver has to different encoding to reconstruct the packet from (similar to the sensys paper by Dubois-Ferriere here, where I found this reference.)
- Coded cooperation: each user sneds different portion of each user's code word via two independent fading paths. I guess at the simplest, it is the decode-and-forward above.
Performance is strongly improved by cooperation in terms of block error rate.
Paper is low level technical reading (no complex analysis or concepts) and clearly presented. It'd be interesting to know what applications --if any-- Nortel has in mind for this work.