Demonstration of DCSK-aided OFDM Design for Cognitive Radio System via USRP

In this paper, we demonstrate two differential chaos shift keying (DCSK) modulated orthogonal-frequency-division-multiplex (OFDM) design for cognitive radio (CR) systems using the universal software radio peripheral (USRP) platform. For two OFDM-based DCSK systems over the non-contiguous spectrum band identified by using the energy detection method, which respectively transmit the reference chaotic sequence with different number of available subcarriers, we propose the implementation modules for transmissions via USRP using the laboratory virtual instrument engineering workbench (LabVIEW), including the modulator, the demodulator and the frame synchronization modules. Subsequently, we provide experimental results to analyze the spectrum efficiency, bit rate error (BER) and frame error rate (FER) over the real wireless channels, which demonstrate the efficient and reliable performances of DCSK aided OFDM systems, and verify the effectiveness of reliable video transmissions.