Spectrum mobility demonstration of SMSE based overlay cognitive radio via software defined radio

Abstract

In our previous work, we have demonstrated an interference avoidance overlay cognitive radio using software defined radio [1][2]. By employing spectrally modulated spectrally encoded (SMSE) framework based multi-carrier transmission waveforms, the cognitive radio is capable of turning off certain subcarriers to avoid interference to the primary users in the band. Hence, the cognitive radio operates over multiple noncontiguous spectrum holes. Here, we extend our previous work to implement and demonstrate spectrum mobility in cognitive radio. Specifically, while the cognitive radio operates over a 2MHz band, the cognitive radio will continuously sense the spectrum wider than the 2MHz band. When the total available spectrum, which is determined by stitching all spectrum holes together in the 2MHz band, is insufficient to support the required cognitive radio transmission, the cognitive radio dynamically moves to a different frequency band where enough spectrum holes exist. We demonstrate real time video transmission between two cognitive radio nodes and seamless transition when the spectrum handoff occurs.