Joint power and spectrum allocation for cooperative cognitive radio network with end user mobility

Cooperative cognitive radio network (CCRN) has gained much attention in the literature of wireless communication. In CCRN, cooperative relaying stimulates primary user (PU) to lease more spectrum to secondary users (SUs). This paper proposes a two stage joint power and spectrum allocation scheme for a CCRN. In the proposed scheme, PU leases unused licensed spectrum to multiple SUs using the frequency division multiple access (FDMA) technique. Here, we have considered that the end users (primary and secondary receivers) can move randomly in any direction. In the first stage, a pricing based dynamic spectrum leasing (DSL) has been used for PU to lease its unused frequency band to the SUs to maximize the revenue. Equal power has been allocated to the PU and all SUs in this stage. In the second stage, a relay assisted DSL scheme has been proposed to induce the PU to lease extra bandwidth to satisfy the increased quality of service (QoS) demands of the SUs, on the condition that QoS of the PU is satisfied. In this stage, power has been allocated to maximize the rate gain of PU and all the SUs. Numerical results have been used to verify the validation of the proposed methodology.