A New Model for Cooperative Cognitive Radio Network Using Coalitional Game.

In this paper we study the resources access problem in cognitive radio networks, especially we are interested in the large number of secondary users (SUs) present in the system. We propose a model based on channel access process when the PU is active, respecting the level of interference authorized by the operator. In this paper, we take secondary users as positive potential cooperators for the primary users. SUs negotiate with PUs for the acquisition of underutilized channels with exceeded interference caused to the PU. The PU will support additional interference. but will benefit from the cooperation of SUs to relay its data. In each transmission frame, one or more secondary users are selected to act as a relay for the primary user and also transmit its own data. We model this cooperation as coalitional game. The utility function considers various factors such as transmission power and noise level. A distributed coalition formation algorithm is also proposed, which can be used by SUs to decide whether to join or leave a coalition. Such a decision is based on whether it can increase the maximal coalition utility value. The objective of this work is to demonstrate that the proposed scheme is able to enhance the network throughput while increasing the opportunity that SUs can access the licensed spectrum owned by PUs.