Spectrum sharing in Cognitive Radio using game theory

Due to the fixed spectrum allocation policy, bandwidth has become one of the scarcest resources for the wireless communications. Therefore, various advanced application, which is very useful in the development of communication system, cannot be used. Currently, the wireless network systems suffer from insufficient bandwidth utilization. However, the licensed users or primary users (PUs) do not use their spectrum all the time. So, to enhance the efficiency of bandwidth usage, the concept of Cognitive Radio (CR) also called secondary user (SU) has emerged as a new design paradigm. By detecting the spectrum holes in PU band as long as they cause no intolerable interference to licensed users, we can make a new dynamic bandwidth sharing strategy between primary and secondary users based on the economic factors, so that the bandwidth utilization and users satisfaction can be enhanced dramatically. We have proposed a simulation model, which allocates free bandwidth of PUs to SUs with an aim to minimize overall bandwidth allocation cost. To share the bandwidth of the primary user with secondary user´s, we have developed an algorithm to minimize the cost of the bandwidth.