Date Added: Jun 2011
In cognitive radio networks, in order to avoid collision to Primary User (PU), Cognitive Radio (CR) user ought to sense the spectrum periodically to certify that PU is absent. However, the collision to PU also occurs due to imperfect sensing or PU's returning when CR user is transmitting. In this paper, the authors study a transmitting-collision tradeoff problem in cognitive radio networks. In particular, they investigate a flexible data transmitting scheme so as to minimize the collision to PU under the probability of detection constrains. In addition, by jointly considering both CR user's traffic and PU's state, the probability of collision is derived in detail.