A Dynamic Spectrum Sharing Scheme Based on SA-OFDM for Cognitive Radios

In this paper, a novel dynamic spectrum sharing scheme combining spectrum adaptation and OFDM for cognitive radio system is proposed. Given spectrum sensing and channel estimation information by the receiver, an improved model due to transmit power thresholds for SA-OFDM system is adopted to achieve spectrum adaptation for unlicensed users. In order to improve spectrum efficiency and reduce computational complexity, a dynamic power allocation algorithm is also proposed. Simulations indicate that the scheme solves the partial interference problem in interference temperature model and improves the spectrum utilization, and the proposed algorithm is appropriate for SA-OFDM system due to its low computational complexity and good performance.