Software Defined Radio Implementation of SMSE Based Overlay Cognitive Radio

In this paper, we demonstrate an adaptive interference avoidance overlay cognitive radio implementation via software defined radio. Using spectrally modulated spectrally encoded (SMSE) framework, we implement a multi-carrier based overlay cognitive radio waveform via USRP (Universal Software Radio Peripheral) software defined radio boards and GNU radio software platform. This cognitive radio is capable of detecting primary users in real time and adaptively adjusting its transmission parameters to avoid interference to primary users. More importantly, this cognitive radio can take advantage of multiple spectrum holes by employing non-contiguous multicarrier transmission technologies. Additionally, we demonstrate that when the primary user transmission changes, the cognitive radio dynamically adjusts its transmission accordingly. We also demonstrate seamless real time video transmission between two cognitive radio nodes, while avoiding interference from primary users and interference to primary users operating in the same spectrum.