Practical Coding Schemes for Cognitive Overlay Radios
The authors develop practical coding schemes for cognitive overlay radios as modeled by the cognitive interference channel, a variation of the classical two user interference channel where one of the transmitters has knowledge of both messages. Inspired by information theoretical results, they develop a coding strategy for each of the three parameter regimes where capacity is known. A key feature of the capacity achieving schemes in these regimes is the joint decoding of both users' code-words, which they accomplish by performing a posteriori probability calculations over a combined trellis. The schemes are shown to perform close to the capacity limit with low error rate.