Modulation identification for cognitive aeronautical air-ground communications

The main objectives for deploying Cognitive Radio (CR) technology in aeronautical communications are to achieve reliable communications and to avoid the expected congestion that is bound to occur in the near future. CR allows a very flexible and dynamic radio management system leading to improved radio spectrum utilization. Realizing CR features in aeronautical communications requires the ability to identify the modulation type of the received signal. In this paper, we introduce a modulation identification algorithm to distinguish the aeronautical signals from other modulated signals based on wavelet transform (WT) analysis. The proposed identification algorithm is able to recognize multicarrier and single-carrier modulated signals and is also able to discriminate linear and non-linear modulations. Simulation results are provided to demonstrate the performance of the identification algorithm for an aeronautical channel modeled as a Ricean fading channel in presence of Gaussian noise.