A Joint Three Compensation round based scheduling Algorithm and a dynamic resource allocation procedure for OFDMA Cognitive systems

In this paper we propose a three compensation round based scheduling algorithm and a dynamic resource allocation procedure for OFDMA based cognitive radio. The main contribution of the proposed scheduling scheme is a high interaction with the external environment, to insure on one hand fairness guarantee between the different real time traffic queues and on the other hand, an enhancement in the Quality of Service level offered by the cognitive network. The contribution of our proposed resource allocation algorithm is to allow a maximum number of cognitive users to use the available spectrum holes and to secure cognitive transmissions. The general contribution of the joint proposed scheduling and resource allocation algorithm is to satisfy the Quality of Service requirements of cognitive users and to respect primary user priority. The resource allocation scheme is implemented in a distributed manner and confirmed by the High Capabilities node during the Conflict resolution procedure. The scheduling procedure is composed by a normal scheduling period and three on-demand compensation rounds based on two different virtual start tags. Our results show that the proposed mechanisms can achieve high overall throughput, high fairness degree, and low over all packet loss percentage.