Adaptive radio scenario evaluation and FMW generation methods for cognitive UWB radio systems

Cognitive ultra-wideband (UWB) radio gains more and more interests from colleges and manufactories. It provides a flexible, low-cost wireless application with the ability of extending spectrum utilization. Cognitive UWB radio combines the advantages of cognitive radio (CR) and UWB together and the applications based on this technique are viewed as the candidates of the next generation wireless technology. We propose an adaptive CR UWB radio scenario evaluation and fundamental modulation waveforms (FMW) generation method in this paper. The proposed method utilizes real-time transform domain technique to evaluate the radio scenarios and generate cognitive UWB FMW. Thus the interference from the CR UWB systems to the primary licensed applications and the interference following the opposite direction can both be suppressed effectively. We introduce the radio scenario evaluation method and the adaptive FMW generation algorithm and compare the interference avoidance ability of the generated waveforms with a common Gaussian impulse based UWB FMW without adopting cognitive techniques by simulation. The comparisons confirm that the proposed radio scenario evaluation method and adaptive FMW generation algorithm are superior to the common UWB FMW scheme without cognitive techniques. The proposed scheme can be adopted in any CR systems operating in any frequency bands.