Joint Frequency Synchronization and Spectrum Occupancy Characterization in OFDM-Based Cognitive Radio Systems
OFDM-based Cognitive Radio (CR) systems are shown to be an effective solution for increasing spectrum efficiency by activating the certain group of subcarriers (sub-bands) in locally available spectrum. However, each CR receiver should synchronize itself to appropriate carrier frequency and to identify currently activated sub-bands. Moreover, energy and bandwidth efficiency of CR systems can be improved if each CR could provide additional characterization of the local spectral content. In this paper a novel joint frequency synchronization and spectrum occupancy characterization method for OFDM-based CR systems is proposed.