Description of a Cognitive Radio Testbed based on USRP Platforms and CogWave

Today, many software defined radio (SDR) platforms are commercially available as off-the-shelf products at a very reasonable price. The concept of cognitive radio (CR) is to have a network of SDRs which can autoconfigure and autonomously change its parameters (waveform, frequency, bandwidth, power) according to the user needs and the electromagnetic environment. CogWave is an open-source software framework aiming at developing CR waveforms. Multiple waveforms have been implemented in CogWave, such as the multichannel DAA-OFDM waveform, the DADS waveform, and GNU Radio waveforms. CogWave provides the means to implement different CR waveforms and to develop rules to switch between different CR waveforms during run-time according to the user needs and the electromagnetic environment. A description of a CR testbed based on USRP platforms and the CogWave framework is given. In the scenario, a jammer perturbs the data transmission between two CR nodes. Results show that when the throughput drops under a predifined threshold, the CR nodes are able to switch from one waveform to another waveform while maintaining communication.