Subchannel and power allocation for OFDMA-based mobile cognitive radio networks

Abstract

Recently, researches on mobile cognitive radio network (CRN) has been paid more attention to, involving spectrum sensing, power control and spectrum access, while no schemes considering both the power and spectrum assignment at the same time. In this paper, an efficient resource allocation (RA) scheme is proposed for the orthogonal frequency division multiple access (OFDMA)-based mobile underlay CRN. Through location-awareness techniques, a realistic model based on predictable channel state information (CSI) is considered. According to the predicting result, the sum average effective capacity (EC) of the secondary network is calculated and aimed to be maximized through the RA scheme. Meanwhile the interference introduced to primary users (PUs) should be less than given thresholds, the signal to interference plus noise ratio (SINR) requirements and the limit of total transmit power of secondary users (SUs) should be satisfied. A stepwise algorithm is introduced to solve the optimization RA at the cost of a low complexity, with four procedures including access control, initial power allocation, subchannel allocation and power allocation. Simulation results demonstrate that the proposed algorithm can achieve not only higher total EC but also higher energy efficiency (EE) and spectrum efficiency (SE).