Cognitive radio using spectrum-sharing and power minimisation

In this paper, we use a Spectrum Sharing/allocation algorithm to implement a Cognitive Radio network without spectral awareness. This allows radio resources to be allocated to primary users and to secondary users in such a way that primary system and secondary system are aware of each other. By doing this, sensing of spectrum holes is avoided but the primary users will be protected and will always be allocated sufficient bandwidth to meet their QoS requirements. However, secondary users also have the concept of QoS and only those that can be given sufficient resources are actually allocated any, so avoiding wasting resources on users that cannot meet their QoS requirements. The scenario adopted is a multi-cell OFDMA network and the resource allocation is formulated as a non-cooperative game: each cell is a player whose aim is to maximise the number of secondary users that can reach their bitrates subject to the premise that all primary users in that cell can achieve their bitrate. Once spectrum is allocated we implement a power-minimisation algorithm to minimise the power consumption in the network while maintaining the number of users meeting their QoS requirements. Simulation results show the beneüt of the approach.