Location Based Relay Selection and Power Allocation in Cognitive Networks

In the case where the source is located within the coverage area of a primary user but far away from destination, the communication can be achieved by establishing a multi-hop router between the user and the source by sharing the frequency band of the primary user. A relay selection algorithm optimizing the number of hops and the total transmit power is proposed based on the location information, and a power allocation algorithm is presented for maximizing the system capacity under the constraints of the total transmit power and the received signal-to-interference ratio. Simulation results show that the algorithm can effectively reduce the total transmit power and improve the system capacity.