An Adaptive OFDMA Platform for IEEE 802.22 Based on Cognitive Radio

CR is the key technology that will enable flexible, efficient and reliable spectrum use by adapting the radio's characteristics to the real-time conditions of the environment. In this paper, an adaptive OFDMA platform is presented to satisfy the requirements of IEEE 802.22, the first standard based on the CR. In the system, two channel types are supported to apply different AMC methods according to user channel environments. Simulation results are also provided to find a better way in constructing diversity subchannels when AMC is performed with average SNR over the whole subcarriers