Optimal Power Transmission for Various Spectrum Sharing Approaches in OFDM based Cognitive Radio Network

In context of effective resource utilization using spectrum sensing and dynamic spectrum access (DSA), Cognitive Radio (CR) has been proposed as versatile and an emerging technology. In order to understand, how OFDM is consider as suitable candidate for cognitive radio, this paper presents various aspects of Orthogonal Frequency Division Multiplexing (OFDM) based cognitive radio. As total transmission rate of CR user is maximized in interference constraint scenario, this paper also formulate problem for optimal transmit power control in OFDM based CR under various spectrum sharing approaches such as underlay, overlay and interweave. Apart from existing works in the literature here we presented mathematical formula for power-allocation schemes for interweave as well as joint underlay and overlay approach. MATLAB simulation shows that with optimal power transmission by CR users, capacity can be improved significantly.